- Created by: kerri_bartlett
- Created on: 15-06-15 16:21
Issues of bias in diagnosis (1)
Cultural bias; classification systems are based on cultural assumptions of what is normal and abnormal behaviour e.g. in the West it is abnormal to hear voices but some religious groups may see this as desirable behaviour; a key method of defining mental illness is through social norms meaning Western classification systems are culturally biased; Psychological tests such as personality or IQ tests are often used which are standarised to Western views and norms; Cochrane et al found black Afro-Caribbeans in the UK are up to 7 times more likely to be diagnosed with schizophrenia also supported by Blake who gave case studies and described them as white or Afro-Caribbean; Johnstone fouond that lower class patients spent longer in hospital, prescribed physical rather than psychological treatments and have poorer prognosis.
Evaluation; over-diagnosis in some cultural groups may be due to genetic differences rather than culture bias e.g. Afro-Caribbeans may be more vulnerable towards schizophrenia however rates aren't as high as in the UK; minority groups in Britain may have more stressful lives and make them more likely to develop schizophrenia - social and environment; Malgady looked at Type 1 & 2 errors, type 2 means they ignore culture bias but may not recognise when treatment is needed accepting a flase null hypothesis, type 1 means ignoring the null hypothesis and that there is a culture bias and so refer healthy patients for mental health treatments; Malgady believes that Type 2 errors are more serious and therefore it is desirable to accept that there is a culture bias when there isnt.
Issues of bias in diagnosis (2)
Gender Bias; the practice of psychiatry is male dominated and so this is the standard by which behaviours are measured, this means that normal female behaviours are seen as signs of illness; anorexia nervosa diagnosis includes the cessation of the menstrual cycle which assumes all sufferers are female; women are more liekly to be diagnosed with depression and phobias and men are more likely to be diagnosed with alcohol abuse or anti-social conduct; histronic personality disorder was correctly diagnosed 80% of the time when the patient was female and 30% when male as female behaviour may be seen as submissive or hysterical; studies rely on male participants as females behaviour fluctuates with hormone levels over the month meaning many studies shouldnt be generalised to female patients and behaviours.
Evaluation; it is possible that some cases of differential diagnosis are due to real differences rather than bias e.g. gender differences in in life experiences such as pregancy and childbirth may explain why women suffer depression; men and women respond differently to depression - women seek help and men use distractions such as alcohol; rates of depression are twice as high in women then in men and similar for bipolar disorder, if there was a systematic gender bias this should be reflected in bipolar disorder too. Desirability of diagnostic system; inaccuracy suggests they shouldnt be used; both ICD and DSM are continually updated so reliability and validity are always improving; psychiatric diagnoses result in labelling e.g. you are schizophrenic not you have schizophrenia, these labels stick throughtout life so misdiagnosis has lifelong implications.
Aetiologies of Schizophrenia (1)
Physiological explanations; Genetic factors - schizophrenia is more common in people with genetic realitives who also have it, closer the relative the higher the risk; 1,000 SZ and 1,000 conrtols found that 16% with FDR and only 7% of the conrtols had schizophrenia; concordance rate of 40.4% for MZ twins and only 7.4% for DZ twins showing that there is genetic influence164 adoptees with biological mothers with schizophrenia were studied and found 11 (6.7%) also had it compared with 4/197 (2%) of controls. Dopamine hypothesis - neurons fire too easily and often; abnormally high D2 receptors meaning more dopamine is binded and therefore more neurons are firing; leads to disturbances in attention, perception and thought found in schizophrenic patients.
Evaluation; family concordance rates may be due to similar child rearing; blind diagnosis in twin studies lead to MZ rates becoming lower but still higher than DZs; MZs are treated more similarly with more identity confusion and experience the same things than DZs meaning concordance rates reflect the environmental differences between the two sets of twins; amphetamine and other drugs cause higher dopamine; anti-psychotic drugs found in post-mortems increased dopamine levels as the neurons struggle with the sudden deficiency; over 90 brain scan studies revealed a substantial overlap with schizophrenics and controls in ventricle size; anti-psychotic medication may be the cause of enlarged ventricals in schizophrenics; Lyon et al found medication increased the density of the brain tissue decreased leading to enlarged ventricles.
Aetiologies of Schizophrenia (2)
Psychological explanations; Freud believed schizophrenia was due to repression and attempts to re-establish ego control; schizophrenia was seen as an infantile state with hallucinations and delusions reflecting the need for ego control; the first time SZs experience voices they turn to others for confirmation but they fail to confirm the reality and the SZs believe they are simply hiding the truth; stressful life events have been found to be associated with schizophrenia, particularly schizphrenic relapses, Brown and Birley found SZs reported twice as many stressful life events when relapsing than a control group; contradictory parenting messages are likely to cause schizophrenia e.g. looking disgusted while saying i love you; this prevents internally coherant contruction of reality; R.D. Laing "schizophrenia is actually a reasonable response to an insane world".
Evaluation; no evidence to support Freud except disordered family patterns can be the cause; Fromm-Reichmann said 'schizophregenic mothers are rejecting and overprotective causing SZ; Meyer-Lindenberg et al found a link between excess dopamine in the prefrontal cortex and working memory; van Os et al found no link between life events and the onset of schizophrenia; in a prospective study patients who had a major life event were less likely to relapse; evidence supporting a link between life events and schizophrenia is only correlational meaning schizophrenia may be the cause not life events; Berger found schizophrenics report higher double-bind than non-schizophrenics but recall is affected by their schizophrenia.
Treatments for Schizophrenia (1)
Chemotherapy; anti-psychotics such as chloropromazine are used to fight the positive symptoms such as hallucinations; conventional antipsychotics bind to but do not stimulate dopamine receptors; A-typical anti-psychotics such as clozapine also fight positive symptoms but also negative symptoms, they act on both dopamine and serotonin levels, they have lower side effects. Evaluation; Davis et al found replace in 55% of 3519 people who were on a placebo drug, but 19% in those who remained on the real drug, 45% on placebo had no relapse; being prescribed medication reinforces that there is 'something wrong with you'; superiority or a-typical is only moderate; tardive dyskinesia is a side effect in 30% of people and irreversible in 75% of cases.
Electroconvulsive Therapy; historically found that schizophrenia was rare in severe epilepsy so they tried inducing seizures; an electric current is passed through 2 scalp electrodes - above the temple on the non-dominant side and the middle of the forehead; they are unconscious due to a barbiturate and given a nerve blocker; 0.6amps is passed through for half a second, 15 treatments are needed. Evaluation; APA looked at studies comparing ECT and simulated ECT, concluded that ECT produced results no different from or worse than medication; ECT and medication together may be more effective (Tharyan and Adams); a major side effect is memory loss, usually temporary and 1 treatment does not result in serious impairment but they get worse over the course of the treatment; NICE say there isnt enough evidence to support the use of ECT, in the UK the use declined 59% between 1979 and 1999.
Treatments for Schizophrenia (2)
Cognitive Behavioural Therapy; helps to identify the irrational thoughts and teach the schizophrenics how to deal with and change these maladaptive thoughts; weekly or fortnightly for 5-20 treatments; patients are encouraged to evaluate the content of their delusions or any voices and to consider ways which they might test the validity of their faulty beliefs; might be set behavioural assignments which can enable them to improve their general level of functioning; therapist may draw a diagram and ask the patient to show them the links between their thinking, behaviour and emotions; CBT cannot completely eliminate the symptoms of schizophrenia but it can make patients better able to cope with their maladaptive behaviours.
Evaluation; outcome studies review how well the patient is doing after the treatment, studies into CBT suggest that patients who recieve such treatments experience fewer hallucinations and delusions and recover their functioning to a greater extent than those who recieve medication alone; 25-50% reduction in positive symptoms in recovery time of patients given medication and CBT; lower drop-out rates and greater patient satisfaction when used alongside medication; it is difficult to assess the effectiveness of CBT apart from medication; in a study of 142 schizophrenics many were not suitable for CBT because psychiatrists said they wouldnt engage with therapy; found that older patients were deemed less suitable than younger patients.
Aetiologies of Depression (1)
Physiological; Twin studies indicate a genetic basis; 177 probands with depression and their same gender co-twin - concordance for MZs was 46% and 20% for DZs suggesting a large genetic factor; diathesis-stress relationship says that genes predispose us to depression but there must be a stressor to produce a depressive reaction; groups with more negative life events and most genetically at risk of depression were found to have the highest levels; short-short alleles are associated with low levels of serotonin and high depression; low noradrenaline and serotonin are found in depressed individuals; Prozac was used to prohibit the reuptake of serotonin confirmed the link between serotonin and depression; diet can also have a large effect as it affects the levels of serotonin produced.
Evaluation; it is possible that vulnerability to more than just depression is inherited through genes; Kendler et al found higher concordance when looking for depression and generalised anxiety disorder; Wilhelm et al found negative life events were associated with depression and short-short produced the highest vulnerability; Kraft et al studied 96 patients treated for 6 weeks with SNRIs found higher response than that with a placebo; changes in diet to produce less serotonin makes patients currently in remission have relapses showing that low serotonin causes depression; however lowering serotonin in all people does not have this effect; aan het Rot et al says depressive episode alters the serotonin system such that a person becomes more vulnerable to the effects of future changes in serotonin.
Aetiologies of Depression (2)
Psychological; Freud said that some depression can be explained by genetic factors but many were linked to childhood experiences of loss or rejection which were repressed; later in life when a loved one or job is lost the repressed feelings turn inwards on themselves; Beck says that depression is due to a negative schema during childhood they are activated in new situations that resemble the original condition in which the schema was learned; negative traid - negative/pessimistic view of self, world and future; learned helplessness by trying but failing to control unpleasant experiences meaning they think they have no control over their life or success; every attribution depressed people make is blaming themselves.
Evaluation; studies have found that people who suffer depression refer to their parents as affectionless supporting Freud's theory of loss; men who lost their fathers during childhood scored higher on the depressive scale; children whose mothers died in childhood suffer depression later in life; could be linked to the lack of affection following from parental figures; 10% who experience loss later become depressed; Hammen and Krantz found that depressed women made more errors in logic when asked to interpret written material from non-depressed patients; Hiroto and Seligman showed that college students who were exposed to uncontrollable aversive events were more likely to fail on subsequent cognitive tasks; Miller and Seligman found depressed students performed worst of all on a similar task; suggest having some degree of control is likely to improve performance, expecially for those who are depressed.
Treatments for Depression (1)
Chemotherapy; antidepressants such as tricyclic and SSRIs are used to treat moderate to severe depression; work by either reducing or enhancing the reuptake of serotonin or noradrenaline; tricyclics block the transporter mechanism; SSRIs such as Prozac block mainly serotonin; has 3 distinct phases - treatment of current symptoms, continuation for 4-6 months and finally maintenance. Evaluation; Kirsch et al found a significant advantage of SSRIs in only severe cases of depression; medication is less useful when given to children adn adolescents; Prozac and SSRIs increased the amount of suicides as it increases suicidal thoughts; in 65 or older the risk of suicide is lessend.
Elecotroconvulsive Therapy; used for severly depressed patients for whom medication has not worked and have been ineffective; used when there is a risk of suicide because ECT has much quicker results than antidepressant drugs; NICE suggests that ECT should only be used where the illness is life-threatening and all other treatments have failed; the seizure, not the electric stimulus, generates improvements in depressive symptoms; restores the brains ability to regulate mood. Evaluation; there is evidence for and against the effectiveness of ECT; 18 studies with 1,144 patients showed that ECT is more effective than drug therapy in the short-term treatment of depression; impaired memory, cardiovascular problems and headaches; Rose et al concluded that at least one third complained of persistent memory loss; unilateral (one side) causes less cognitive problems but may be just as effective as bilateral (both sides).
Treatments for Depression (2)
Cognitive behaviour therapy; emphasises the role of maladaptive thoughts and beliefs in the origin and maintenance of depression; when people think negatively about themseves and their life they become depressed; CBT aims to identify these maladaptive thoughts and any dysfunctional behaviours that may be contributing to depression; 16-20 sessions adn is focused on current problems and current dysfunctional thinking; record any emotions they feel, automatic negative thougths and then realistic thoughts that challenge the negative ones; by challenging the dysfunctional thoughts clients are encouraged to try out new ways of thinking and ultimately behaving; are encouraged to take up or restart an activity they enjoy.
Evaluation; Butler et al found 16 publlished meta-analyses and concluded that CBT was highly effective for treating depression; however Holmes said thta it is less effective than anti-depressant drugs and psychotherapies; studies are normally on highly selected individuals with only depression and no other symptoms; NICE recommends CBT as the most effective psychological treatment for moderate and severe depression; 15% of the successive outcome is down to whether the therapist condducted the therapy effectively; clients engagement with homework is crucial to improvement and the therapist must get the client involved with this; CBT appears less suitable for people who have high levels of dysfunctional beliefs that are both rigid and resistant to change; also less suitable in situations where high levels of stress in the individual reflect realistic stressors in the persons life that therapy cannot solve.