Schizophrenia Flashcards
What type of disorder is Schizophrenia?
Psychotic
Positive symptoms of schizophrenia
Hallucinations: unusual sensory experiences; can be auditory, visual etc.
Delusions: irrational beliefs, including paranoia, delusions of persecution, delusions of grandeur
Speech disorganisation: incoherent speech, changes of topic mid sentence.
Negative symptoms of schizophrenia
Avolition: difficulty in beginning or keeping up with goal-directed activity, reduced motivation.
Speech poverty: reduced amount and quality of speech, delay in response during conversation.
Validity of diagnosis
the extent to which we are measuring what we intend to measure, in the context of schizophrenia, can we correctly diagnose it when it occurs
Reliability of diagnosis
refers to consistency, if two clinicians saw the same patient, would they draw the same conclusion and give the same diagnosis
Rosenhan: Aim
investigate whether the sane can be distinguished from the insane
Rosenhan Sample: study one
8 pseudopatients, age 20+, included Rosenhan.
Variety of professions, 3F, 5M.
Used false names and professions
Rosenhan’s involvement was known only to the hospital administrator and chief psychologist.
Rosenhan method: study one
Pseudopatients sought admission to a hospital, claiming to hear unfamiliar voices of their sex saying words like ‘empty’ and ‘hollow’. They had to convince staff they were sane. They behaved ‘normally’, indicated no symptoms, and were co-operative. In four hospitals, they observed staff responses to ‘when am I likely to be discharged?’
Rosenhan results: study one
All were successfully admitted, and not detected by staff in the hospitals. All but one received diagnoses of schizophrenia, and were discharged with a diagnosis of ‘schizophrenia in remission’. Experience was negative and unpleasant. Hospital staff avoided interaction with patients. Most individuals experienced depersonalisation and powerlessness
Rosenhan sample: study two
Psychiatric staff at a teaching hospital, judgements were made on 193 patients
Rosenhan method: study two
Staff were told that over 3 months, one or more pseudopatients would attempt to gain admission. Each staff member rated each patient, on a 10 point scale according to the likelihood that the patient was an imposter
Rosenhan results: study two
41 patients were rated with high confidence to be pseudopatients by at least one member of the staff. No pseudopatients actually presented themselves to the hospital.
Cheniaux et al (2009)
Two psychiatrists independently diagnosed 100 patients using both the DSM and the ICD criteria
Psychiatrist one diagnosed 26 under the DSM and 44 under the ICD
Psychiatrist two diagnosed 13 under the DSM and 24 under the ICD
This implies that diagnosis is not reliable, between clinicians or between systems
Implies that the systems are not valid, either the DSM is underdiagnosing or the ICD is overdiagnosing
They’re reviewed as we gain knowledge, helps clinicians to have clarity and accuracy in diagnosis
Jacobson et al (2005)
100 Danish patients with a history of psychosis were assessed using the criteria in the ICD-10; 98% concordance rate was found between clinicians.
Soderberg et al (2005)
81 raters from various psychiatric outpatient clinics rated eight case vignettes using the DSM-IV; 81% concordance rate was found.
Causes of issues with reliability and validity
Co-morbidity, gender bias, culture bias and symptom overlap
Co-morbidity
The occurrence of two different conditions together; if conditions occur together frequently, this calls into question the validity of their classification and diagnosis because they could actually be a single condition.
Research - Co-morbidity
Buckley et al (2009) reported that 50% of schizophrenics had depression, 15% had panic disorders, 29% had PTSD and 47% experienced substance abuse
Symptom overlap
Considerable overlap of symptoms of schizophrenia and other conditions; this means that under ICD a patient that receives a diagnosis of schizophrenia, but receives a diagnosis of a different condition (e.g. bipolar depression) under the DSM.
Research - Symptom Overlap
Ophoff (2011) assessed genetic material of 50,000 participants, of seven gene locations on the genome associated with schizophrenia, three were also associated with bipolar disorder
Gender bias
When psychological research and theories offer a view that does not justifiably represent the experiences of both men and women
Research - Gender Bias
Longnecker et al (2010) reviewed studies on the prevalence of schizophrenia and concluded that since the 1980s more men have been diagnosed with schizophrenia than women
Culture bias
A tendency to ignore cultural differences and interpret phenomena through the “lens” of one’s own culture.
Research - Culture Bias
Bhugra et al (1997) collected cases of psychosis among African-Caribbeans and White British individuals, for 18-29 year olds, the diagnosis rates were 14.7 per 10,000 for African Caribbeans and 7.5 per 10,000 for White British individuals
Ripke et al (2014)
Meta-analysis of studies linking variations across the human genome
Compared the genetic makeup of 37,000 patients and 113,000 control participants.
Found 108 different genetic variations that increased risk of schizophrenia.
Many related to the functioning of neurotransmitters including dopamine
Aetiologically heterogeneous
Caused by different genes in different people
Polygenic
Caused by several different genes
Gottesman (1991)
Identified percentage of people who develop schizophrenia if they have relatives with schizophrenia.
As the number of genes you share with an individual with Sz increases so does your risk of Sz
