Schizophrenia Flashcards
Schizophrenia
Psychosis in the form of profound disruption to ones cognition and emotion, affecting language, thought, perception, emotions and sense of self.
Positive Symptoms
An excess or distortion of normal functions. This includes hallucinations, delusions, disorganised speech, and disorganised of catatonic behaviour.
Disorganised speech
Thoughts interrupt speech/ derail topics. Echolalia- rhyming words, Neologism- making up words.
Catatonic behaviour
Inability to motivate or initiate a task, rigid postures or aimless motor activity.
Negative Symptoms
Symptoms that reflect a reduction/ loss of normal function. This includes alogia, avolition, anhedonia and affective flattening.
Alogia
Lessening of speech fluency and productivity.
Avolition
Reduction of interest and desires.
Affective Flattening
Reduction in the range and intensity of emotions.
Anhedonia
Loss of interest in pleasurable activities.
Milev et al 2005- defecit syndrome/ symptoms
Deficit syndrome = more than 2 negative symptoms for 12 months or longer. Those with deficit syndrome have more pronounced cognitive deficits and poorer outcomes.
Makinen et al 2008- negative symptoms ratio
1 in 3 schizophrenics suffer with negative symptoms.
Schizophrenia Diagnosis Kappa Score
According to Regier et al 2013 the diagnosis had a kappa score of 0.46.
Reliability Cultural Differences
- Significant variations between countries when it comes to a SZ diagnosis.
- Copeland 1971- 134 US and 194 British psychiatrists a description of patients: 69% of the US ones diagnosed SZ, whereas only 2% of the British did.
- Luhrman et al 2015- interviewed 60 adults, 20 from each of Ghana, India and the US,. Those from Africa and India had positive experiences with their voices, where the American ones were violent and hateful- no consistent characteristics.
Reliability- inter-rater
Whaley 2001- inter-rater reliability correlations in the diagnosis of SZ as low as 0.11 (kappa score).
Reliability- unreliable symptoms
Mojtabi and Nicholson 1995- 50 senior psychiatrists differentiated between bizarre and non bizarre delusions, producing an inter-rater reliability of 0.4- subjective.
Rosenhan et al 1972
Sent pseudo-patients to 12 different hospitals. They phoned the hospital for an appointment, stating that they had voices in their head that were ‘empty’, ‘hollow’ and ‘thud’. After they were admitted, they stopped stimulating symptoms and told staff that they were better. They remained in the hospital between 7 and 52 days (average of 19).
Validity- gender bias
- Some diagnostic categories in the DSM may be more biased toward pathologising one gender due to research being more focused on one.
- Broverman et al 1970- clinicians in the US equated a mentally healthy adult behaviour with a male.
- Longenecker et al 2010- men have been diangosed with schizophrenia more often than women since the 1980s.
- Cotton et al 2009- female schizophrenics tend to function better than males.
- Loring and Powell 1988- 290 male and female psychiatrists read patients behaviour: when described as male or unspecified, 56% gave diagnosis, when described as female, 20% gave diagnosis.
Validity- symptom overlap
- Many symptoms of schizophrenia are also prevalent in depression and bipolar disorder.
- Ellason and Ross 1995- pointed out that people with dissociative identity disorder have more schizophrenic symptoms than most diagnosed schizophrenics.
- Read 2004- most schizophrenics could also have at least one other diagnosis.
Validity- co-morbidity
- Multiple disorders can occur at once in schizophrenics.
- Buckley et al 2009- estimate that co-morbid depression occurs in 50% of patients and substance abuse in 47%.
- Swets et al 2014- meta analysis showed that at least 12% of schizophrenics had OCD, 25% displayed symptoms.
- Calls into question whether it is a single condition.
- Weber et al 2009- analysed 6 million hospital discharge records and found thjat 45% had evidence of other disoders, but also found evidence of other non-psychiatric disorders like asthma or diabetes.
Validity- prognosis
The prognosis varies with 20% recovering to their previous functioning, 30% showing improvement with some relapses and 10% achieving long lasting progress/ improvement. Diagnosis has little predictive value.
Genetic Explanation
Schizophrenia tends to run in families, but only among individuals who are genetically related. It is thought that it is a combination of genes that make a person more vulnerable to developing schizophrenia.
Family Studies (Gottesman and Shields 1991)
Children with two schizophrenic parents had a concordance rate of 46%, with one parent had a rate of 13% and with a sibling 9%.
Twin Studies (Joseph 2004)
Calculated from a poll of all twin studies that MZ twins had a concordance rate of 40.4%, while DZ twins had a rate of 7.4%. More recent blind studies (researchers don’t know if they are MZ or DZ twins, concordance rates have been lower for MZ twins.
Adoption Studies (Tienari et al 2000)
164 adoptees (biological mother had schizophrenia) 11 (6.7%) received a diagnosis compared to 4 (2%) of 197 control adoptees.