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Transcript of Schizophrenia
& diagnosis Biological
treatments Clinical Characteristics Positive & negative symptoms The symptoms of schizophrenia are typically divided into positive & negative symptoms.
Positive symptoms are those that appear to reflect an excess or distortion of normal functions.
Negative symptoms are those that appear to reflect a diminution or loss of normal functions, which often persist during periods of low (or absent) positive symptoms.
Under DSM-IVR, the diagnosis of schizophrenia requires at least a one month duration of 2 or more positive symptoms. Positive symptoms Negative symptoms Delusions- Bizarre beliefs that seem real to the person with schizophrenia, but they are not real. Sometimes these delusions can be paranoid in nature. Delusions may also involve inflated beliefs about the person's power & importance.
Experiences of control- The person may believe they are under the control of an alien force that has invaded their mind and/or body.
Hallucinations- Bizarre, unreal perceptions of the environment that are usually auditory (hearing voices) but may also be visual (seeing lights, objects or faces), olfactory (smelling things) or tactile (e.g. feeling that bugs are crawling on or under the skin).
Disordered thinking- The feeling that thoughts have been inserted or withdrawn from the mind. In some cases the person may believe their thoughts are being broadcast so that others can hear them. Tangential, incoherent or loosely associated speech is used as an indicator of thought disorder. Affective flattening- A reduction in the range & intensity of emotional expression, including facial expression, voice tone, eye contact & body language.
Alogia- Poverty of speech, characterised by the lessening of speech fluency & productivity. This is thought to reflect slowing or blocked thoughts.
Avolition- The reduction of, or inability to initiate and persist in goal-directed behaviour (for example sitting in the house for hours every day doing nothing); it is often mistaken for apparent disinterest. Reliability Reliability Reliability refers to the consistency of a measuring instrument, such as a questionnaire or a scale, to assess, for example, the severity of schizophrenic symptoms.
Reliability of such questionnaires or scales can be measured in terms of:
whether 2 independent assessors give similar diagnoses (inter-rater reliability)
whether tests used to deliver these diagnoses are consistent over time (test-retest reliability). Inter-rater reliability Test-retest reliability The publication of DSM-III in 1980 was specifically designed to provide a much more reliable system for classifying psychiatric disorders.
In a review of the success of DSM-III, Carson claimed that DSM-III had fixed the problem of inter-rater reliability once & for all.
Psychiatrists now had a reliable classification system, so this should have led to much greater agreement over who did, or not, have schizophrenia. Cognitive screening tests such as RBANS (Repeatable Battery for the Assessment of Neuropsychological Status) are important in the diagnosis of schizophrenia as they measure the degree of neuropsychological impairment.
Wilks et al administered 2 alternate forms of the test to schizophrenic patients over intervals varying from 1-134 days. The test retest reliability (correlation of scores across the 2 test periods) was high at 0.84. Evaluation of reliability Inter-rater reliability Unreliable symptoms Test-retest reliability Comparing DSM and ICD Despite the claims for increased reliability in DSM-III (and later revisions), over 30 years later there is still little evidence that DSM is routinely used with high reliability by mental health clinicians.
Recent studies e.g. Whaley have found inter-rater reliability correlations in the diagnosis of schizophrenia as low as +0.11.
Rosenhan highlighted the unreliability of diagnosis in his study where "normal" people presented themselves to psychiatric hospitals in the US claiming they heard an unfamiliar voice in their head saying the words "empty", "hollow" and "thud". They were all diagnosed as having schizophrenia and admitted. Throughout their stay, none of the staff recognised that they were actually normal. In a follow-up study, Rosenhan warned hospitals of his intention to send out more "pseudopatients". This resulted in a 21% detection rate, although none actually presented themselves. For a diagnosis of "schizophrenia", only one of the characteristic symptoms is required "if delusions are bizarre". However, this creates problems for diagnosis.
When 50 senior psychiatrists in the US were asked to differentiate between "bizarre" and "non-bizarre" delusions, they produced inter-reliability correlations of only around +0.40, forcing the researchers to conclude that even this central diagnostic requirement lacks sufficient reliability for it to be a reliable method of distinguishing between schizophrenic and non-schizophrenic patients (Mojtabi and Nicholson). Measures of cognitive functioning are vital in the diagnosis of schizophrenia, therefore must have test-retest reliability of several measures of attention and information processing in 14 chronic schizophrenics.
Prescott et al analysed the test-retest reliability of several measures of attention and information processing in 14 chronic schizophrenics. Performance of these measures was stable over a 6 month period. Cheniaux et al investigated the inter-rater reliability of the diagnosis of schizophrenia according to both DSM-IV and ICD-10. Although the inter-rater reliability was above +0.50 for both classificatory systems, schizophrenia was more frequently diagnosed according to ICD-10 than DSM-IV criteria. Cultural differences in diagnosis The reliability of diagnosis in schizophrenia is further challenged by the finding that there is massive variation between countries.
Copeland gave 134 US & 194 UK psychiatrists a description of a patient. 69% of the US psychiatrists diagnosed schizophrenia but only 2% of the British psychiatrists gave the same diagnosis. Validity Validity Comorbidity Positive or negative symptoms Prognosis Evaluation of validity Comorbidity & medical complications Comorbidity & suicide risk Ethnicity may lead to misdiagnosis Symptoms Validity refers to the extent that a diagnosis represents something that is real & distinct from other disorders & the extent that a classification system such as ICD and DSM measures what it claims to measure.
Reliability and validity are linked because a diagnosis cannot be valid if it is not reliable. Comorbidity is an important issue for the validity of diagnosis of mental illness. It refers to the extent that 2 (or more) conditions co-occur.
Psychiatric comorbidities are common among patients with schizophrenia. These include substance abuse, anxiety & symptoms of depression.
Buckley et al estimate that comorbid depression occurs in 50% of patients, and 47% of patients also have a lifetime diagnosis of comorbid substance abuse.
Such comorbidity creates difficulties in the diagnosis of a disorder and also in deciding what treatment to advise. Klosterkotter et al assessed 489 admissions to a psychiatric unit in Germany to determine whether positive or negative symptoms were more valid for a diagnosis of schizophrenia. They found that positive symptoms were more useful for diagnosis than were negative symptoms. People diagnosed as schizophrenic rarely share the same symptoms, nor is there evidence that they share the same outcomes.
The prognosis for patients varies with about 20% recovering their previous level of functioning, 10% achieving significant and lasting improvement, and about 30% showing some improvement with intermittent relapses (Bentall et al).
A diagnosis of schizophrenia, therefore, has little predictive validity- some people never appear to recover from the disorder, but many do. The poor levels of functioning found in many schizophrenics may be less the result of their psychiatric disorder and more to do with their untreated comorbid physical disorders.
A US study (Weber et al) examined nearly 6 million hospital discharge records to calculate comorbidity rates. Psychiatric and behaviour related diagnoses accounted for 45% of comorbidity. However, the study also found evidence of many comorbid non-psychiatric diagnoses.
Many patients with a primary diagnosis of schizophrenia were also diagnosed with medical problems, including hypothyroidism, asthma, hypertension & type 2 diabetes.
The authors concluded that a consequence of being diagnosed with a psychiatric disorder such as schizophrenia is that patients tend to receive a lower standard of medical care, which in turn adversely affects their prognosis. People with schizophrenia pose a relatively high risk for suicide, with comorbid depression being the major cause for suicidal behaviour.
For example, among patients in the National Comorbidity Survey (Kessler et al), the rate for attempted suicide rose from 1% for those with schizophrenia alone to 40% for those with at least one lifetime comorbid mood disorder. Research suggests that within the UK and elsewhere, rates of schizophrenia among African-Caribbeans are much higher when compared with white populations. For example, Harrison et al reported that the incidence rate for schizophrenia was 8 times higher for African-Caribbean groups (46.7 per 100,000) than for white groups (5.7 per 100,000).
Some of this increase can be explained as a result of poor housing, higher rates of unemployment & social isolation. However, there also remains the possibility that misdiagnosis may, in part, result from factors such as cultural differences in language & mannierisms and difficulties in relating between black patients and white clinicians. Despite the belief that identification of the symptoms of schizophrenia would make for more valid diagnoses of the disorder, many of these symptoms are also found in many other disorders, such as depression and bipolar disorder.
Ellason and Ross point out that people with dissociative identity disorder (DID) actually have more schizophrenic symptoms than people diagnosed as being schizophrenic. Genetic factors Family studies Twin studies Family studies (e.g. Gottesman) find individuals who have schizophrenia and determine whether their biological relatives are similarly affected more often than non-biological relatives.
Family studies have established that schizophrenia is more common among biological relatives of a person with schizophrenia, and that the closer the degree of genetic relatedness, the greater the risk.
For example, children with 2 schizophrenic parents have a concordance rate of 46%, children of one schizophrenic parent 13% and siblings 9%. Twin studies offer a unique opportunity for researchers to investigate the relative contributions of genetic & environmental influences.
If monozygotic (identical) twins, who share 100% of their genes, are more concordant (similar) in terms of a trait like schizophrenia than dizygotic (fraternal) twins who share only 50% of their genes, then this suggests that the greater similarity is due to genetic factors.
Joseph calculated that the pooled data for all schizophrenia twin studies carried out prior to 2001 shows a concordance rate for monozygotic twins of 40.4% and for dizygotic twins of 7.4%.
More recent, methodologically sound studies (e.g. those using "blind" diagnoses where researchers do not know whether the twin they are assessing is MZ or DZ) have tended to report a lower concordance rate for monozygotic twins.
However, despite this, twin researchers still argue that even these findings support the genetic position, because they provide a monozygotic concordance rate that is many times higher than the dizygotic concordance rate. Adoption studies Because of the difficulties of disentangling genetic and environmental influences for individuals who share genes and environment, studies of genetically related individuals who have been reared apart are used.
Probably the most methodologically sound study of this type was carried out by Tienari et al in Finland. Of the 164 adoptees whose biological mothers had been diagnosed with schizophrenia, 11 also received a diagnosis of schizophrenia, compared to just 4 of the 197 control adoptees (born to non-schizophrenic mothers).
The investigators concluded that these findings showed that the genetic liability to schizophrenia had been "decisively confirmed". Evaluation Family studies Twin studies Adoption studies Research has shown that schizophrenia appears to run in families, supporting the argument for a genetic basis for the disorder.
However, many researchers now accept that the fact that schizophrenia appears to run in families may be more to do with common rearing patterns or other factors that have nothing to do with heredity.
For example, research on expressed emotion has shown that the negative emotional climate in some families may lead to stress beyond an individual's coping mechanisms, thus triggering a schizophrenic episode. A crucial assumption underlying all twin studies is that the environments of monozygotic (MZ) twins and dizygotic (DZ) twins are equivalent. It is therefore assumed that the greater concordance for schizophrenia between MZ twins is a product of greater genetic similarity rather than greater environmental similarity.
However, as Joseph points out, it is widely accepted that MZ twins are treated more similarly, encounter more similar environments (i.e. are more likely to do things together) and experience more "identity confusion" (i.e. frequently being treated as "the twins" rather than as 2 distinct individuals) than DZ twins.
Joseph argues that as a result, there is reason to believe that the differences in concordance rates between MZ & DZ twins reflect nothing more than the environmental differences that distinguish the two types of twin. A central assumption of adoption studies is that adoptees are not "selectively placed", i.e. adoptive parents who adopt children with a schizophrenic biological parent are no different from adoptive parents who adopt children whose background is normal.
Joseph claims that this is unlikely to have been the case, particularly in the early studies. In countries like Denmark and the US, potential adoptive parents would have been informed of the genetic background of children prior to selection for adoption.
As Kringlen points out- "Because the adoptive parents evidently received information about the child's biological parents, one might wonder who would adopt such a child." Methodological problems with heredity studies Most schizophrenia adoption studies would not have found statistically significant differences between the adoptees born to schizophrenic and non-schizophrenic parents without broadening the definition of schizophrenia to include non-psychotic "schizophrenia spectrum disorders".
For example, in a study by Kety et al, no cases of full schizophrenia were found among the first degree relatives of adopted children identified with a schizophrenia spectrum disorder. The dopamine hypothesis Dopamine Dopamine is one of the many different neurotransmitters that operate in the brain. The dopamine hypothesis states that messages from neurons that transmit dopamine fire too easily or too often, leading to the characteristic symptoms of schizophrenia.
Schizophrenics are thought to have abnormally high numbers of D2 receptors on receiving neurons, resulting in more dopamine binding and therefore more neurons firing. Dopamine neurons play a key role in guiding attention, so disturbances in this process may well lead to the problems relating to attention, perception and thought found in people with schizophrenia (Comer). Amphetamines Antipsychotic drugs Parkinson's disease Amphetamine is a drug with special relevance for our understanding of schizophrenia.
It is a dopamine agonist, stimulating nerve cells containing dopamine causing the synapse to be flooded with this neurotransmitter.
Large doses of the drug can cause the characteristic hallucinations and delusions of a schizophrenic episode. Although there are many different types of antipsychotic drug, they all have one thing in common- they block the activity of dopamine in the brain.
By reducing stimulation of the dopamine system, these drugs eliminate symptoms, such as hallucinations and delusions.
The fact that these drugs (known as dopamine antagonists because they block its action) alleviated many of the symptoms of schizophrenia, strengthened the case for dopamine being a significant contributory factor in this disorder. Low levels of dopamine activity are found in people who suffer from Parkinson's disease, a degenerative neurological symptoms disorder.
It was found that some people who were taking the drug L-dopa to raise their levels of dopamine were developing schizophrenic-type (Grilly). Evaluation Post-mortem studies Evidence from neuroimaging research Evidence from treatment A major problem for the dopamine hypothesis is the fact that drugs can be used to treat schizophrenia by blocking dopamine activity increase it as neurons struggle to compensate for the sudden deficiency.
Haracz, in a review of post-mortem studies of schizophrenics, found that most of those studied who showed elevated dopamine levels had received antipsychotic drugs shortly before death. Post-mortems of schizophrenics who had not received medication, on the other hand, showed that these individuals had normal levels of dopamine. The development of sophisticated neuroimaging techniques such as PET scans has allowed researchers to investigate dopamine activity more precisely than in previous studies that had relied on measures of the metabolites (waste products) associated with dopamine activity.
However, neuroimaging studies have, as yet, failed to provide convincing evidence of altered dopamine activity in the brains of individuals with schizophrenia (Copolov and Crook). Much of the evidence supporting the dopamine hypothesis comes from the success of drug treatments that attempt to change levels of dopamine activity in the brain.
The basic mechanism of antipsychotic drugs is to reduce the effects of dopamine and so reduce the symptoms of schizophrenia.
For example, Davis et al carried out a meta-analysis of 29 studies that analysed the effectiveness of antipsychotic treatment compared with a placebo.
They found that at the end of the clinical trial, relapse occurred in 55% of the patients whose drugs were replaced by a placebo, but only 19% of those who remained on the drug. The possibility that schizophrenia is a biological disorder that originated in distant ancestral humans is supported by the fact that it is found in even the most remote racial enclaves. Australian Aborigines became isolated from the rest of humankind about 60,000 years ago, yet schizophrenia has been observed in this racial group (Torrey).
Stevens & Price have proposed a novel hypothesis for the persistence of schizophrenia. They suggest that schizoid personalities have acted in the past to perform the valuable function of dividing tribal communities when they become too large (e.g. may help to sustain given dwindling food resources).
As a group grows in size there comes a point when the optimum group size is exceeded and splitting the group will increase the reproductive fitness of each individual. According to this perspective, schizophrenia would be an adaptation whose function is to facilitate group splitting. This would be achieved through the influence of a charismatic leader, who, because of his psychotic thinking, can separate himself from the dogma of the main group and create a new community with a new world view (Stevens and Price).
Stevens & Price maintain that schizoid symptoms such as mood changes, bizarre beliefs, hallucinations & delusions of grandeur would induce discontented group members to leave. Evolutionary perspective Conventional antipsychotics Conventional antipsychotic drugs Conventional antipsychotics such as chlopromazine are used primarily to combat the positive symptoms of schizophrenia such as hallucinations & thought disturbances- products of an overactive dopamine system. The basic mechanism of conventional antipsychotic drugs is to reduce the effects of dopamine and so reduce the symptoms of schizophrenia.
Conventional antipsychotics are dopamine antagonists in that they bind to dopamine receptors (particularly the D2 receptors) but do not stimulate them, thus blocking their action.
By reducing stimulation of the dopamine system in the brain, antipsychotic drugs such as chlorpromazine can eliminate the hallucinations and delusions experienced by people with schizophrenia. Effectiveness of conventional antipsychotics Appropriateness of conventional antipsychotics Many studies that have evaluated the effectiveness of antipsychotic medication have done so by comparing the relapse rates of those on medication with those on a placebo.
For example, a review by Davis et al found a significant difderence in terms of relapse rates between treatment and placebo groups in every study reviewed, thus demonstrating the therapeutic effectiveness of these drugs.
One of the studies in the Davis et al review (Vaughn & Leff) found that antipsychotic medication did make a significant difference, but only for those living with hostility and criticism in their home environment. In such conditions, the relapse rate for those on medication was 53%, but for those in the placebo condition the relapse rate was 92%. For individuals living in more supportive home environments, there was no significant difference between those on medication (12% relapse rate) and those in a placebo condition (15% relapse rate). Conventional antipsychotics have many worrying side effects, including tardive dyskinesia (uncontrollable movements of the lips, tongue, face, hands and feet). About 30% of people taking antipsychotic medication develop tardive dyskinesia, and it is irreversible in 75% of cases (Hill).
Ross & Read argue that being prescribed medication reinforces the view that there is "something wrong with you". This prevents the individual from thinking about possible stressors such as life history or current circumstances that might be a trigger for their condition. In turn this reduces their motivation to look for possible solutions that might alleviate these stressors and reduce their suffering. Placebos Ross & Read argue that studies such as the Davis et al study are not a fair comparison of treatment versus non-treatment because, under the placebo conditions, the patient is actually in a drug withdrawal state.
With sudden and complete withdrawal of antipsychotic medication, the previously blocked dopamine system becomes flooded with dopamine because of the heightened sensitivity and increased numbers of dopamine receptors (which happens as a response to a drug-induced blockade of the dopamine system during medication). This results in a total overwhelming of the dopamine system. Consequently, claim Ross & Read, a proportion of the relapses in the placebo condition can be explained by the withdrawal effects of the drugs.
Davis et al analysed the results of 29 studies. They found that relapse occurred in 55% of the patients whose drugs were replaced by a placebo, and 19% of those who remained on the drug. Ross & Read point out that these figures are misleading, as they also indicate that 45% of those on a placebo did benefit. Likewise, of the 81% who benefited from the drug, the data suggest that a large proportion (i.e. 45%) would also have benefited from a placebo. Atypical antipsychotics Atypical antipsychotic drugs Atypical antipsychotic drugs (such as clozapine) also combat positive symptoms of schizophrenia but there are claims that they have some beneficial effects on negative symptoms as well.
Atypical antipsychotic drugs act on the dopamine system, but are thought to block serotonin receptors in the brain too.
Kapur & Remington, however, suggest that these drugs do not involve serotonin or other neurotransmitters, but only the dopamine system and the D2 receptors in particular. They help by only temporarily occupying the D2 receptors and then rapidly dissociating to allow normal dopamine transmission.
It is this characteristic of atypical antipsychotics that is thought to be responsible for the lower levels of side effects (such as tardive dyskinesia- involuntary movements of the mouth and tongue) found with these drugs compared to conventional antipsychotics. Appropriateness of atypical antipsychotics Effectiveness of atypical antipsychotics Although the production of the new "atypical" antipsychotics raised expectations for the outcomes possible with medication, a meta-analysis of studies revealed that the superiority of these drugs compared to conventional antipsychotics was only moderate (Leucht et al). This analysis found that 2 of the new drugs tested were only "slightly" more effective than conventional antipsychotics, while the other 2 were no more effective.
The claim that atypical antipsychotics are particularly effective with the negative symptoms of schizophrenia also has very marginal support. In the Leucht et al study, 2 of the atypical drugs were "slightly" more effective than conventional antipsychotics, one was "as effective" and one "slightly worse". One of the main claims of the atypical antipsychotics is the lower likelihood of tardive dyskinesia. This claim was supported in a study by Jeste et al, which found tardive dyskinesia rates in 30% of people after 9 months of treatment with conventional antipsychotics, but just 5% for those treated with atypical antipsychotics.
Atypical antipsychotics may ultimately be more appropriate in the treatment of schizophrenia because there are fewer side effects, which in turn means that patients are more likely to continue their medications and therefore see more benefits. Ethical issues The problems associated with the use of antipsychotic medication raises significant ethical issues. Critics argue that if side effects, deaths and psychosocial consequences were taken into account, a cost-benefit analysis of its advantages would most probably be negative.
In the US recently, a large out-of-court settlement was awarded to a tardive dyskinesia sufferer on the basis of the Human Rights Act 1988, which states that "no one shall be subjected to inhuman or degrading treatment or punishment" (Chari et al). Electroconvulsive therapy (ECT) Historical origins What happens in ECT? Effectiveness of ECT Appropriateness of ECT ECT and schizophrenia The idea that schizophrenia could somehow be cured by inducing seizures followed reports that dementia praecox (an early name for what we now know as schizophrenia) was rare in patients with severe epilepsy, and that seizures in patients with dementia praecox somehow reduced the symptoms of the disorder.
The first studies of the clinical use of this technique specifically for the treatment of schizophrenia were disappointing, with lower rates of recovery for ECT patients compared to those who did not receive ECT (Karagulla). An electric current is passed between 2 scalp electrodes to create a seizure. An electrode is placed above the temple of the non-dominant side of the brain, and a second in the middle of the forehead (unilateral ECT).
The patient is first injected with a short-acting barbiturate, so they are unconscious before the electric shock is administered.
They are then given a nerve-blocking agent, paralysing the muscles of the body to prevent them contracting during the treatment and causing fractures.
A small amount of electric current (approximately 0.6 amps), lasting about half a second, is passed through the brain.
This produces a seizure lasting up to one minute, which affects the entire brain. A patient usually requires 3-15 treatments. An American Psychiatric Association review listed 19 studies that had compared ECT with "stimulated ECT" (patients are given general anesthesia but no ECT).
It concluded that ECT produced results that were no different from or worse than antipsychotic medication.
However, an Indian study (Sarita et al) found no difference in symptom reduction between 36 schizophrenia patients given either ECT or stimulated ECT. Because there are significant risks associated with ECT, including memory dysfunction, brain damage and even death, use of this technique as a treatment for schizophrenia has declined.
In the UK, the decline between 1979 and 1999 was 59% (Read) Tharyan & Adams carried out a review of 26 studies in order to assess whether ECT resulted in any meaningful benefits for schizophrenic patients (e.g. in terms of hospitalisation, change in mental state and behaviour). They included a range of studies that compared ECT with a placebo condition, with "stimulated" or "sham" ECT and with antipsychotic medication.
They found that when ECT was compared with placebo or stimulated ECT, more people improved in the real ECT condition. However, there was no indication that this advantage was maintained over the medium or long term.
When ECT was compared with antipsychotic medication treatment, results favoured the medication groups. There was some limited evidence to suggest that when ECT was combined with antipsychotic medication, this resulted in a greater improvement in mental state.
The authors conclude that a combination of ECT and medication may be appropriate when rapid reduction of symptoms is required, or when patients show limited response to medication alone. Psychological theories Psychodynamic Evaluation Cognitive Evaluation Freud believed that schizophrenia was the result of 2 related processes, regression to a pre-ego stage and attempts to re-establish ego control.
If the world of the schizophrenic has been particularly harsh, for example if his or her parents were cold and uncaring, an individual may regress to this early stage in their development before the ego was properly formed and before he or she had developed a realistic awareness of the external world.
Schizophrenia was thus seen by Freud as being an infantile state, with some symptoms (e.g. delusions of grandeur) reflecting this primitive condition, and other symptoms (e.g. auditory hallucinations) reflecting the person's attempts to re-establish ego control. There is no research evidence to support Freud's specific ideas concerning schizophrenia, except that subsequent psychoanalysts have claimed, like him, that disordered family patterns are the cause of this disorder.
For example, Fromm-Reichmann described "schizoprenogenic mothers" or families who are rejecting, overprotective, dominant and moralistic, as important contributory influences in the development of schizophrenia.
Studies have shown that parents of schizophrenic patients do behave differently from parents of other kinds of patient, particularly in the presence of their disturbed offspring (Oltmanns et al), but this is likely to be a consequence of their children's problems as a cause. This explanation of schizophrenia acknowledges the role of biological factors in causing the initial sensory experiences of schizophrenia, but claims that further features of the disorder appear as individuals attempt to understand those experiences.
When schizophrenics first experience voices and other worrying sensory experiences, they turn to others to confirm the validity of what they are experiencing. Other people fail to confirm the reality of these experiences, so the schizophrenic comes to believe that others must be hiding the truth.
They begin to reject feedback from those around them and develop delusional beliefs that they are being manipulated and persecuted by others. There is much evidence of a physical basis for the cognitive deficits associated with schizophrenia, for example research by Meyer-Lindenberg et al, which found a link between excess dopamine in the prefrontal cortex, and working memory.
The suggestion that "madness" is consequence of disbelieving others receives curious support from a recent suggestion for treatment. Yellowlees et al have developed a machine that produces virtual hallucinations, such as hearing the TV tell you to kill yourself, or one person's face morphing into another. The intention is to show schizophrenics that their hallucinations are not real. As yet there is no evidence that this will provide a successful treatment. Socio cultural factors Family relationships (double bind theory) Evaluation Expressed emotion Evaluation Bateson et al suggest that children who frequently receive contradictory messages from their parents are more likely to develop schizophrenia. For example, if a mother tells her son she loves him, yet at the same time turns her head away in disgust, the child receives two conflicting messages about their relationship on different communicative levels, one of affection on the verbal level, and one of animosity on the non-verbal level. The child's ability to respond to the mother is incapacitated by such contradictions because one message invalidates the other.
These interactions prevent the development of an internally coherent construction of reality, and in the long run, this manifests itself as schizophrenic symptoms (e.g. flattened affect and withdrawal). These ideas were echoed in the work of psychiatrist R.D. Laing, who argued that what we call schizophrenia is actually a reasonable response to an insane world. Importance of family relationships The importance of family relationships in the development of schizophrenia is supported by an adoption study by Tienari et al. In this study those adopted children who had schizophrenic biological parents were more likely to become ill themselves than those children with non-schizophrenic biological parents. However, this difference only emerged in situations where the adopted family was rated as disturbed. In other words the illness only manifested itself under appropriate environmental conditions. Genetic vulnerability alone was not sufficient. There is some evidence to support this particular account of how family relationships may lead to schizophrenia. Berger found that schizophrenics reported a higher recall of double-bind statements by their mothers than non-schizophrenics. However, this evidence may not be reliable, as patients' recall may be affected by their schizophrenia.
Other studies are less supportive. Liem measured patterns of parental communication in families with a schizophrenic child and found no difference when compared to normal families. Hall & Levin analysed data from various previous studies and found no difference between families with and without a schizophrenic member in the degree to which verbal and non-verbal communication were in agreement. Another family variable associated with schizophrenia is a negative emotional climate, or more specifically, Expressed emotion (EE) is a high communication style that involves criticism, hostility, and emotional over-involvement. High levels of EE are most likely to influence relapse rates. A patient returning to a family with high EE is about 4 times more likely to relapse than a patient returning to a family with low EE (Linszen et al).
In a study of the relapse rates among schizophrenics in Iran, Kalafi and Torabi found that the high prevalence of EE in Iranian culture (overprotective mothers and rejective fathers) was one of the main causes of schizophrenic relapses. It appears that the negative emotional climate in these families arouses the patient and leads to stress beyond his or her already impaired coping mechanisms, thus triggering a schizophrenic episode. The effects of expressed emotion have received much more universal empirical support than the double-bind theory. However, there is the issue of whether EE is a cause or an effect of schizophrenia.
Either way it has led to an effective form of therapy where high-EE relatives are shown how to reduce levels of expressed emotion.
Hogarty et al found that such therapy can significantly reduce relapse rates. However, as with all therapies, it is not clear whether the EE intervention was the key element of the therapy or whether other aspects of family intervention may have helped. Socio-cultural factors Life events & schizophrenia Evaluation Labelling theory Evaluation A major stress factor that has been associated with a higher risk of schizophrenic episodes is the occurrence of stressful life events. These are discrete stresses, such as the death of a close relative or the break-up of a relationship. For example, a study by Brown & Birley found that, prior to a schizophrenic episode, patients who had previously experienced schizophrenia reported twice as many stressful life events compared to a healthy control group.
The mechanisms through which stress factors trigger schizophrenia are not known, although high levels of physiological arousal associated with neurotransmitter changes are thought to be involved (Falloon et al). Expressed emotion and culture Although findings on expressed emotion have been replicated cross-culturally, expressed emotion is much less common in families of people with schizophrenia outside the West (Jenkins and Kamo).
One possible explanation for this is that non-Western cultures are less individualist and less committed to concepts of personal responsibility than Western societies, such as the US and UK. Thus, they are less likely to blame someone with schizophrenia for their actions. Retrospective studies Prospective studies Brown & Birley supported the claim that life events play an important role in schizophrenia. They found that about 50% of people experience a stressful life event in the 3 weeks prior to a schizophrenic episode, while only 12% reported one in the nine weeks prior to that.
A control sample reported a low and unchanging level of stressful life events over the same period, suggesting that it was the life events that triggered the relapse. Unlike retrospective studies, which study events in the past, prospective studies monitor the presence of absence of stressful life events prospectively (i.e. in the future).
Hirsch et al followed 71 schizophrenic patients over a 48-week period. It was clear that life events made a significant cumulative contribution in the 12 months preceding relapse rather than having a more concentrated effect in the period just prior to the schizophrenic episode (as suggested by the retrospective studies). Not all evidence supports the role of life events. For example, van Os et al reported no link between life events and the onset of schizophrenia. Patients were not more likely to have had a major stressful life event in the 3 months preceding the onset of their illness. In a prospective part of the study, those patients who had experienced a major life event went on to have a lower likelihood of relapse.
Evidence that does suggest a link between life events and schizophrenia is only correlational. It could be that the beginnings of the disorder (e.g. erratic behaviour) were the cause of the major life events. Furthermore, life events after the onset of the disorder (e.g. losing one's job, divorce) may be a consequence rather than a cause of mental illness. The labelling theory of schizophrenia, popularised by Scheff, states that social groups construct rules for members of their group to follow. The symptoms of schizophrenia (e.g. hallucinations and delusions, and bizarre behaviours) are seen as deviant from the rules we ascribe to "normal" experience. If a person displays these unusual forms of behaviour, they are considered deviant, and the label of "schizophrenic" may be applied.
Once this diagnostic label is applied it becomes a self-fulfilling prophecy that promotes the development of other symptoms of schizophrenia (Comer). In a review of the evidence, Scheff evaluated 18 studies explicitly related to labelling theory. He judged 13 to be consistent with the theory and 5 to be inconsistent, thus concluding that the theory was supported by the evidence.
A study which he assessed as supporting labelling theory was the Rosenhan study. Rosenhan found that once the "label" of schizophrenia had been applied, the "diagnosis" continued to influence the behaviour of staff toward the patient, even when this was no longer warranted. Cognitive-behavioural therapy Cognitive behavioural therapy The basic assumption of CBT is that people often have distorted beliefs which influence their behaviour in maladaptive ways. For example, someone with schizophrenia may believe that their behaviour is being controlled by someone or something else.
Delusions are thought to result from faulty interpretations of events, and cognitive therapy is used to help the patient to identify & correct these.
An example of a delusional belief:
EVENT: See a man outside house.
INTERPRETATION: He's following me.
FEELING: Scared, paranoid.
BEHAVIOUR: Take evasive action, avoid going out. CBT techniques Outcome studies Effectiveness Appropriateness In CBT, patients are encouraged to trace back the origins of their symptoms in order to get a better idea of how the symptoms might have developed.
They are also encouraged to evaluate the content of their delusions or of any internal voices they hear, and to consider ways in which they might test the validity of their faulty beliefs.
Patients might also be set behavioural assignments with the aim of improving their general level of functioning. The learning of maladaptive responses to life's problems is often the result of distorted thinking by the schizophrenic, or mistakes in assessing cause & effect (for example assuming that something terrible has happened because they wished it).
During CBT, the therapist lets the patient develop their own alternatives to these previous maladaptive beliefs, ideally by looking for alternative explanations and coping strategies that are already present in the patient's mind. Outcome studies measure how well a patient does after a particular treatment, compared with the accepted form of treatment for that condition. Outcome studies of CBT suggest that patients who receive cognitive therapy experience fewer hallucinations and delusions and recover their functioning to a greater extent than those who receive antipsychotic medication alone.
Drury et al found benefits in terms of a reduction of positive symptoms and a 25-50% reduction in recovery time for patients given a combination of antipsychotic medication and CBT. A subsequent study by Kuipers et al confirmed these advantages, but also noted that there were lower patient drop-out rates and greater patient satisfaction when CBT was used in addition to antipsychotic medication. Research has tended to show that CBT has a significant effect on improving the symptoms of patients with schizophrenia. For example, Gould et al found that all seven studies in their meta analysis reported a statistically significant decrease in the positive symptoms of schizophrenia after treatment.
Most studies of the effectiveness of CBT have been conducted with patients treated at the same time with antipsychotic medication. It has been difficult, therefore, to assess the effectiveness of CBT independent of antipsychotic medication. CBT for schizophrenia works by trying to generate less distressing explanations for psychotic experiences, rather than trying to eliminate them completely.
Negative symptoms may well serve a useful function for the person and so can be understood as "safety behaviours". For example, within a psychiatric setting, the strong expression of emotions might lead to increases in medication or hospital admission. Similarly, inactivity and withdrawal might be seen as a way of avoiding making positive symptoms worse. CBT, therefore, offers some hope of alleviating these maladaptive thought processes.
The use of CBT in conjunction with medication seems to have benefits, but it is commonly believed within pschiatry that not everyone with schizophrenia may benefit from CBT.
For example, in a study of 142 schizophrenic patients in Hampshire, Kingdon and Kirschen found that many patients were not deemed suitable for CBT because psychiatrsts believed they would not fully engage with the therapy.
In particular they found that older patients were deemed less suitable than younger patients. Psychodynamic therapy (psychoanalysis) Psychoanalysis Psychodynamic techniques Effectiveness Appropriateness Psychoanalytic therapy is based on the assumption that individuals are often unaware of the influence of unconscious conflicts on their current psychological state.
The aim of psychoanalysis is to help bring these conflicts into the conscious mind where they can be dealt with. The psychoanalytic appraoch to schizophrenia assumes that all the symptoms are meaningful and are a product of the life history of the individual patient. The therapist attempts to create an alliance with the patient by offering real help with what the patient perceives as the problem. The more severe the disorder for the individual patient, the more support the therapist must provide. In the early part of the 20th century, Freud believed that schizophrenics could not be analysed because they could not form a transference with the analyst. Transference refers to the process by which emotions that are originally associated with one person (such as a parent) are unconsciously shifted onto the analyst. In the wake of Freud's pessimistic assessment of the value of psychoanalysis in the treatment of schizophrenia, only a handful of therapists specialised in this technique, or variations of it.
However, other forms of psychodynamic therapy have sometimes been found successful in treating schizophrenia. These have in common with Freudian psychoanalysis the belief that the first task of any psychodynamic therapy is to win the trust of the patient and to build a relationship with them.
The therapist achieves this by replacing the harsh and punishing conscience, probably based on the patient's parents, with one that is less destructive & more supportive. As the patient gets healthier, the patient takes a more active role (and the therapist a less active role) in their own recovery. Malmerg & Fenton argue that it is impossible to draw definite conclusions for or against the effectiveness of psychodynamic therapy. In fact the Schizophrenia Patient Outcome Research Team (PORT) has even argued that some forms of psychodynamic therapy are harmful for patients with schizophrenia. Despite this, a meta-analysis of 37 studies (Gottdiener) concluded that psychodynamic therapy was an effective treatment for schizophrenia.
Research on the effectiveness of psychodynamic therapy for schizophrenia has produced contradictory findings. For example, May found that patients treated with this therapy together with antipsychotic medication had significantly better outcomes than those treated with the therapy alone. What was even more damning was that antipsychotic medication alone was also superior to psychodynamic therapy.
However, Karon and VandenBos found the opposite, with patients treated with therapy improving more than those receiving medication alone. Despite the fact that the evidence for the effectiveness of psychodynamic therapy in schizophrenia is not entirely convincing, the treatment guidelines of the APA (American Psychiatric Association) recommend that "supportive interventions" such as psychodynamic therapy are appropriate when combined with antipsychotic treatments.
One argument against using psychodynamic therapy is that its expense (psychodynamic therapists are expensive and the treatment is usually long term) prevents it being adopted on a large scale. Some critics argue that because it does not appear more effective than antipsychotic medication, psychodynamic therpay is not worth the extra expense.
However, there is evidence to suggest that the overall cost of treating schizophrenics decreases with the use of therapy because they are less likely to seek inpatient treatment and are more likely to gain employment (Karon & Vanden Bos). Meta-analysis Methodological limitations Gottdiener reviewed 37 studies published between 1954 and 1999 covering 2642 patients with a mean age of 31.1 years. They found that, overall, 66% of those receiving psychotherapy improved after treatment, compared with only 35% of those who did not receive psychotherapy. Specific results are summarised:
Type of psychotherapy
Results showed that psychoanalytic and cognitive-behavioural therapies produced similar levels of therapeutic benefit.
Use with antipsychotic medication
Results showed no difference in improvement when psychotherapy was accompanied by antipsychotic medication compared to psychotherapy alone.
Outpatients versus inpatients
Results showed that outpatients (treated outside the context of a psychiatric institution) improved at a higher rate than inpatients. In the Gottdiener study, there were a number of methodological issues that prevented firm conclusions being drawn about the effectiveness of psychotherapy as a treatment for schizophrenia.
Number of studies- The relatively small number of studies meant that it was difficult to assess the impact of variables, such as therapist training or experience.
Random allocation- About half of the studies reviewed did not allocate patients randomly to treatment conditions, thus introducing a treatment bias that may possibly have affected the results. Ethical issues Research on therapies for schizophrenia must be carried out in a way that does not place vulnerable individuals at risk.
The BPS advise that when participants take part in a psychological investigation they should not be increasing the probability that they would come to any form of harm.
The possibility for harm is heightened when dealing with vulnerable groups, such as patients with schizophrenia. The potential for harm in outcome studies of schizophrenia include those associated with medication discontinuation, the use of placebo conditions and capacity for informed consent.