Schizophrenia

Flussdiagrammknoten

• SCHIZOPHRENIA

• A psychotic break from reality.

• Can be caused by depression, family, genes and the environment.

• Classification and Diagnostic Manuals

• ICD-10

• DSM-V

• (International Classification of Diseases) created by WHO to classify illness. Used by UK and 110 other countries. Version 10 was implemented in 1994. More that 14,000 codes for diseases, signs, symptoms, abnormal findings and external causes. Monitors diseases, counts deaths and causes.

• A classification and description of over 200 mental disorders-grouped in terms of common features. V is the most recent update. This system is mostly used in the USA. This is the best for mental disorders as it specifically focuses on them and is applied to only one country.

• Positive Symptoms: Appears to reflect an excess or distortion of normal functioning.

• Types of Positive Symptom

• HALLUCINATIONS: A sensory experience that doesn't exist but is real for the person. They can be any of the five senses. E.g. Seeing dead people.

• DELUSIONS: Persistant ideas which are clearly untrue but are experienced as true. There can be delusions of persecution, people plotting against them (e.g. That the FBI are out to get them.) Or delusions of reference, events referring directly to them when they don't.

• DISORGANISED SPEECH: Hard to follow, may produce a "word salad." The jumbled words make no sense and a word may be chosen for rhyme rather than meaning.

• NEGATIVE SYMPTOMS: Describes thoughts and behaviour the person used to have before they became ill but no longer have/or have to a lesser extent been taken away from their psyche

• Types of Negative Symptom

• SPEECH POVERTY: May appear to have little interest in conversation. May have disrupted speech or long pauses in the flow of speech or responding to conversation.

• AVOLITION: The person may shun social contact and prefer to be by themselves. A lack of general will to interact.

• APATHY: A lack of interest in activities of previous interest and importance.

• RELIABILITY AND VALIDITY IN THE DIAGNOSIS OF SCHIZOPHRENIA

• RELIABILITY

• The consistency of measurements

• INTER-RATER RELIABILTY: That different clinicians must reach the same conclusions measured by the kappa score. It is important to reach consistent results.

• There is poor reliability diagnosing sz because even central diagnostic requirement lacks sufficient reliablity for it to be a reliable method of distinguishing between schizophrenic and non-schizophrenic patients. It relies on people's subjective interpretations and different classification systems.

• ROSENHAN 1973: An investigation to see whether mentally healthy patients would be admitted into hospital. 8 psuedopatients called a mental hospital saying that they were hearing voices. It took 7-52 days to be declared sance after behaving normally and following ward rules. Psychiatrists failed to detect the sanity of patients.

• Cultural Differences

• COPELAND 1971 gave 134 USA and 194 British psychologists a description of a patient. 69% of the US diagnosed sz compared to 7% of British. LAHMANN 2015 interviewed 60 adults, 20 of Ghana, Indian and USA. Ghanian and Indian subjects had positive experiences with voices and USA had more violent.

• Reliabilty has been improved in culture because of different classification systems, updated and reviewed versions and training of medical staff.

• VALIDITY

• Whether an observed effect is a genuine one. Measures accuracy.

• SYMPTOM OVERLAP: Where symptoms of a disorder may not be unique to that disorder but may be found in other disorders. Can make sz diagnosis difficult.

• CO-MORBIDITY: The extent that two or more conditions or diseases occur simutaneously in a patient. Such as depression.

• Gender Bias

• Likey to occur if diagnosis is dependent on the gender. Can be stereotypical thoughts on gender. Woman are more likely to be diagnosed with sz

• If there isn't a valid diagnosis, there will be lots of misdiagnosis which can influence people's lives concerning the stigma around it. Those who haven't got a diagnosis may go without necessary treatment.

• BIOLOGICAL DIAGNOSIS OF SZ

• GENETICS

• FAMILY STUDIES

• GOTTESMAN 1991: Children with two sz parents had a concordance rate of 46%. Children with one sz parent had a rate of 13% and siblings were 9%.

• TWIN STUDIES

• JOSEPH 2004: pooled data for all sz twin studies prior to 2001. It showed a concordance rate of 40.4% for MZ twins and 7.4% for DZ twins.

• Supports a genetic position because they have a concordance rate for MZ twins as it is higher that DZ twins.

• A limitation of using twin research is that MZ twins are expected to do things in a more similar environment and experience more identity confusion than DZ twins

• ADOPTION STUDIES

• TIENARI 2000: found that in Finland, of 164 adoptees whose biological mothers had been diagnosed with sz, 11 (6.7%) received a sz diagnosis compared to 4 (2%) of 197 adoptees.

• The findings show a genetic liability to sz had been "decisively confirmed".

• A limitation of using adoption studies is that adoptees may be selectively placed. JOSEPH 2004 claimed this is likely. In countries like Denmark and the USA potential parents would be informed of the genetic background of children prior to adoption.

• DOPAMINE HYPOTHESIS

• The original dopamine hypothesis claims an excess of dopamine is associated with the positive symptoms of sz. This means that the neurons that use dopamine fire too often and transmit too many messages. Evidence provided shows that amphetamines increase the amount of dopamine.

• The revised dopamine hypothesis claims that positive symptoms of sz are caused by an excess of dopamine receptors. These receptors lead to more firing and an overproduction of messages.

• The dopamine hypothesis is supported by the success of drug treatments. Antipsychotics reduces the effects of dopamine therefore reducing the symptoms of sz.

• Leutch 2013 found in a meta-analysis of 212 studies that the antipsychotic drugs are hugely effective. Those given the actual drug rather than the placebo were significantly more effective.

• Supporting evidence is also inconclusive. Moncrieff 2009 found that stimulant drugs (like cocaine) include sz episodes as these types of drugs affect other transmitters as well as dopamine. Evidence for dopamine concentration in post-mortem brain scans are inconclusive.

• NOLL 2009: claims there is strong evidence against the original and revised dopamine hypothesis. He argues that anti-psychotic drugs don't alleviate hallucinations and delusions. In some people hallucinations and delusions are present despite high dopamine levels.

• NEURAL CORRELATES

• Changes in neuronal events and mechanisms that results in characteristic symptoms of a behaviour or mental disorder.

• FMRI brain scans by JOHNSTONE et al found sz had enlarged ventricles but non-sufferers did not. Suggests sz is linked to loss of brain tissue. 

• Evidence doesn't show that it is caused by sz but it may be an effect of sz. However, brain structure may be caused by something else. Sz may be though a cause of the abnormal structures.

• PSYCHOLOGICAL EXPLANATIONS OF SZ

• FAMILY DYSFUNCTION

• The presence of problems within a family that contribute to relapse rates in recovering szs, including a lack of warmth between parent and child.

• DOUBLE BIND THEORY

• Suggests that children who frequently receive contradictory messages from their parents are more likely to develop sz. These interactions prevent the development of an internally coherent construction of reality and this manifests as sz symptoms.

• EXPRESSED EMOTION

• A negative emotional climate. This is a family communication where members of the psychiatric patient discuss that patient in a critical or hostile manner which indicates an emotional over-involvement or power-concern with the patient or behaviour. A patient returning to high EE is four times more likely to relapse than a patient whose family is low in EE. People with sz have a lower tolerance for intense environmental stimuli.

• BERGER 1965 found szs reported a higher recall of double bind statements by their mothers than non-szs. LIERN 1974 measured patterns of parental communication in families with a sz child and found no difference when compared to "normal" families. HALL AND LEVIN 1980 found no difference between families with and without a sz member concerning verbal and non-verbal.