- SZ is more common among biological relatives of a person.
- The closer the degree of relatedness, the higher the risk.
- Joseph (2004): concordance rate of 40.4% identical twins and 7.4% for non-identical twins.
- Tienari et al., (2000): 164 control adoptees in Finland whose biological mothers had SZ, 11 had SZ, comparedto 4/197 control adoptees.
- Research has shown that SZ patients have 15% bigger ventricles.
- Part of the brain structure (neuroanatomy)
- However may be because of antipsychotic medication.
- Dopamine is a neurotransmitter that helps operate the brain.
- Dopamine is fired too quickly or too often.
- Amphetamines: cause synapse to flood with dopamine, producing hallucinations and dellusions.
- Antipsychotic Drugs: block acitivity of dopamine and hallucinations and dellusions stop.
- Parkinson's Disease: given L-dopa to increase dopamine levels, they develop SZ symptoms.
- Conventional Antipsychotics (reduce dopamine).
- Davis et al., (1980): analysed 29 studies, relapse occured 55% on placebos, 19% on real drug.
- Ross and Read (2004): 45% on placebos actually benefitted.
- side effects: 30% will develop Tardive Dyskenesia; being perscribed medication will affirm something is wrong with you and reduces motivation to look for possible solutions.
- Atypical Antipsychotics (block dopamine and serotonin)
- claims to reduce negative symptoms aswell, but marginal support.
- findings show only slightly more effective or the same as conventional.
- lower risk of Tardive Dyskenesia.
- fewer side effects, patients more likely to continue treatment.
Electro-convulsive Therapy (ECT)
- Electric current passed between 2 scalp electrodes to create a seizure (0.6 amps).
- 3 - 15 treatments required.
- Tharyan and Adams (2005): more people improved than on 'sham ECT', however results favoured medication.
- potentially life saving
- side effects - memory dysfunction, brain damage, death.
- ethical issues, Rose et al., (2005): meta-analysis, 1/2 felt ill informed, 1/3 felt forced into treatment.
Cognitive Behavioural Therapy (CBT)
- Assumption that people have a distorted belief which influences their behaviour.
- Event --> interpretation --> feeling --> behaviour.
- Patients encouraged to 'reality-test' their symptoms and change their faulty thought patterns.
- Gould et al.,: all 7 studies in meta-analysis reported decrease of positive symptoms after treatment, however diffcult to assess because patients are usually also on mediation.
- not everyone can benefit, 142 SZ patients - many deemed not suitable, older people less likely.
- Aims to treat underlying cause using different techniques, e.g. dream analysis, free association.
- Once conflicts are made conscious, they can be resolved.
- Gottdiener (2000): meta-analysis of 37 studies, concluded it was an effective treament (66% improved).
- not worth extra effort when medication is available?
Characteristics of Schizophrenia
- SZ is a psychotic disorder characterised by the loss of contact with reality.
- DSM-IV-TR - SZ diagnosis requires one month of two or more positive symptoms.
- Onset between mid-teens and early 30s.
- Affects 1% of UK population.
Positive Symptoms - distortion of normal function.
- experiences of control
- disordered thinking
Negative Symptoms - lack of normal function.
- affective flattening (lack of emotion)
- alogia (poverty of speech)
- avolition (loss of ability to initiate action or goal-directed behaviour)
Reliability of Diagnosis
Can scientists agree who has it?
Rosenham (1973): normal people admitted to psychiatric hospitals claiming they heard voices saying 'empty', 'thud' and 'hollow'.
- all but 1 were diagnosed as SZ.
- in a follow-up study, Rosenham warned of sending out more pseudopatients, but did not send any - detection rate was 21%.
Copeland et al., (1971): gave description of patient to 13 US and 194 UK psychiatrists.
- 69% US diagnosed as SZ, 2% UK diagnosed as SZ.
Validity of Diagnosis
Can scientists agree on what it is?
- people with Dissociative Identity Disorder have more SZ symptoms than people with SZ.
Bentall et al., (1988): reviewed research into causes, outcomes and treatment of SZ.
- conclude SZ was not a useful scientific category.