- Created by: sana
- Created on: 09-05-11 21:24
Classification and Diagnosis of Schizophrenia
A) Characteristic symptoms: 2 or more, for some significant time during a 1 month period; (delusions, hallucinations, disorganised speech, disorganised behaviour, negative symptoms)
B) Social/Occupational Dysfunction
D) Exclusion of mood disorders
E) Exclusion of known organic causes
Positive symptoms (Type I) : delusions, hallucinations, disordered thinking, experiences of control
Negative symptoms (Type II) : alogia (poverty of speech), affective flattening (lack of expressed emotions), avolition (inability to persist in goal directed behaviour)
*Cultural differences: diagnosis, 69% US psychiatrists, 2% UK.
Issues with Reliability and Validity in Diagnosing
Reliability: extent to which psychiatrists can AGREE when INDEPENDANTLY ASSESSING patients
> Rosenhan, psuedopatients. Questions reliability.
> Little evidence that DSM is used by psychiatrists. Inter-rater reliability 0.11
> Positive more useful for diagnosis. When 50 psychiatrists asked to class bizzare and non-bizzare behaviour, inter-reliability of 0.40 --> lacks sufficient reliabilty
Validity: What exactly IS Schizophrenia?
>Some symptoms cross over into other mental disorders such as depression, bipolar etc.
>No evidence of shared outcomes; little predictive validity (some recover,some don't)
> Ellason and Ross found people with Dissociative Identity Disorder (DID), in fact are more 'schizo' than schizos themselves!
Biological Explanations of Schizophrenia 1
Diathesis-Stress relationship, where biological disposition, but only develop if significant stressors.
Research shows in family studies that risk of developing more if parent/sibling has it. However, could be 'cause similar environment.
Twin studies found MZ twins higher concordance rate than DZ twins, monozygotic at 40%, and dizygotic twins at 7.4%. More recent 'blind' studies where researcher doesn't know whether twin is DZ/MZ, found lower than 40%, but still higher than DZs. Joseph (2004) said that MZ twins usually treated the same, environment, experiences etc., not individuals but pair & therefore could be environment still, not genes.
To seperate genetics from environment, can look at adoption studies. Still found genetics likely to be a factor. However, can be parenting again as they're given info on child prior to adoption and will be aware of risk of developing schizo, still take on..
Biological Explanations of Schizophrenia 2
Dopamine hypothesis: schizos thought to have abnormally high D2 receptors. Evidence as follows...
AMPHETAMINES: dopamine agonist, ie, gives more out. Large doses create hallucinations & delusions
ANTI-PSYCHOTIC DRUGS: all one thing in common, block activity of dopamine. Found eliminates symptoms
Parkinson's disease: sufferers have less dopamine, so medication (L-Dopa) gives it out, some started developing symptoms
PET scans allow to investigate dopamine activity more precisely, but can't provide evidence of altered dopamine activity
Torrey (2002) found larger ventricles.. META analysis found not true, found only bigger when on drugs - which could be causing the enlarged ventricle. Also poor brain development could be reason for large ventricle and reason of negative symptoms.
Psychological Explanations for Schizophrenia 1
Psychodynamic: Freud believed it was result of regression to pre-ego stage (especially the infantile characteristics such as poverty of speech) and attempts to re-establish ego control (through hearing voices etc). Little evidence to prove. Behaviour of parents may be consequence not cause
Cognitive: Further features of disorder stem from trying to understand experiences..reject feedback & develop delusions.
Life events and schizo: Retrospective studies and prospective studies both show relapse when stressful life events. However, can be consequence not cause, eg divorce because problems coping with schizo.
Labelling Theory: The symptoms of schizo seen as deviant from what we call 'normal', label of 'schizo' may be applied.Then self-fulfiling prophecy Scheff
Psychological Explanations for Schizophrenia 2
Double-bind theory - children who recieve contradictory messages from parents more likely to develop schizo. Difficulty in interaction 'cause don't fully understand, and this prevents an internal coherant construction of reality. This then manifests itself into schizo symptoms.
Expressed emotions - Expressed emotion (EE) family communication style, eg. criticism, hostility, & emotional over-involvement. Patients with high level EE families, more likely to relapse. Iran study by Kalafi and Torabi proves this as main cause for relapse.but is this cause/effect? therapy helps.
van Os et al. found no link in life events and schizophrenia. Evidence only correlational link.
Tienari et al. found that kids whose parents were schizo more likely to develop even in adopted families. However, these families were disturbed anyway, so the illness only manifested itself under appropriate environmental conditions, and genetic vulnerability alone, not sufficient. Berger (1965) found schizos higher recall of double-bind statements by mothers than non-schizos. However, reliable? Recall affected by schizo? Liem found no difference from normal families in the degree to which verbal and non-verbal communication in agreement. Scheff found 13/18 labelled became schizos. evidence.
Biological Therapies for Schizophrenia
Convential antipsychotics : used to combat +ve symptoms, dopamine antogonists, bind to dopamine receptors, but don't stimulate. Block. Effective as shown by Davis et al study, sig dif in relapse rates, 55% who on placebo relapsed. However, that means 45% on placebo benefitted too. Vaughn & Leff found this drug effective for those living in hostile environment. Side effects 'tardive dyskinesia' - uncontrollable movements- about 30% of users develop this & in 75% it's irreversable. Prescribing drugs makes the person think there's something wrong with them, stress more. Prevents them from finding stressors and alleviating them.
Atypical antipsychotics: combat `+ve but there are claims that combats -ve too. Also act on dopamine system but thought to block serotonin too. However, some say dont involve serotonin but only dop, spesh D2 receptors. Less side effects compared to conventional eg. tardive dyskinesia only 5% instead of 30% with conventional . However, meta-analysis found only moderate diff in comparison to convent. Also, claim that allevaites negative symptoms, only moderately. Not much signif dif.
Electroconvulsive therapy (ECT). Tharyan & Adams reviewed 26 studies. Found more people improved in real ECT over sham/simulated. American Psychiatric Association reviewed 19 studies and concluded that ECT results no more diff or worse than antipsychotics. Risks of ECT : memory dysfuntion, brain damage, death.
Pscyhological Therapies for Schizophrenia 1
Cognitive Behavioural Therapy -
Faulty thinking leads to faulty behaviour. In relation to schizophrenia, one may believe that their behaviour is being controlled by something or someone else. Delusions are thought to result from faulty thinking and CBT aims to identify and correct this. In CBT, patients are encouraged to find the origin of symptoms, to evaluate content of their delusions by testing validity of faulty beliefs. Behavioural assignments may be set to improve functioning. During CBT the therapist makes the patient think of alternatives to the alreadt present maladaptive response, trying to find an alternative coping strategy already present in the patient's mind.
Outcome studies suggest that it is effective and patients experience fewer hallucinations & recover to a greater extent. Gould et al found that 7/7 studies in meta-analysis reported signif decrease in +ve symptoms. However, most research conducted on patients recieving antipsychotics as well as CBT so diff to examine CBT independantly. Also, not everyone is suitable for therapy, and won't respond/engage properly. (Kingdon & Kirschen)
Pscyhological Therapies for Schizophrenia 2
Pyschodynamic therapy - Psychoanalysis
Based on theory that we are often unaware of influence of unconcious conflicts. The aim of psychoanalysis is to help bring these into the concious mind, and deal with them. It assumes that all symptoms are meaningful and are a product of life history of the individual. The therapist will create an alliance with patient by offering help to what patient sees as main problem. The more severe, the more support given. Freud believed schizos couldnt be analysed because they couldnt form 'transference' (where emotions originally associated with one person are shifted onto the analyst unconsciously) Because of this, not many therapists in this field. However, variations eg. win trust of patient and build relationship, replace harsh conscience with less destructive one. As patient gets healthier, he takes a more active role in recovery, and therapist less active.
Some research shows that it is in fact, more harmful to schizos. But Gottdeiner's meta-analysis concluded that it was effective. Still though there were methodoligical issues with this as only 37 studies (difficult to assess impact of variable eg. therapist training/experience) and also almost half of them didnt allocate random patients. May found that antipsychotics alone more powerful than psychodynamic therapy, but Karon & VandenBos found opposite. Expensive too, but believed to gain employment by Karon & Vandenbos. Ethical issues, schizos vulnerable, shouldnt come to any psychological harm eg.medical discontinuation, placebo, and informed consent