Diagnosis of schizophrenia

Schizophrenia

A severe mental health condition where contact with reality and insight are impaired

Positive symptoms of schizophrenia

Atypical symptoms experienced in addition to common experiences like hallucinations and delusion

Delusions

A positive symptom

Beliefs that have no basis in reality e.g. a person believes that they are someone else or that they are a victim of a conspiracy.

Hallucinations

A positive symptom

Sensory experiences that have either no basis in reality or are distorted perceptions of things that are there.

Negative symptoms of schizophrenia

Atypical experiences that represent the loss of a common experience like a loss of clear thinking or a loss of motivation.

Avolition

A negative symptom

Loss of motivation to carry out tasks which results in lowered activity levels

Speech poverty

A negative symptom

Reduced frequency and quality of speech

Co-mobordity

The occurrence of 2 conditions together e.g. schizophrenia and a personality disorder at the same time.

In cases where 2 conditions are frequently diagnosed together it calls into question the validity of classifying the conditions separately.

Symptom overlap

Occurs when 2 or more conditions share symptoms.

Calls into question the validity of classifying the 2 conditions separately

Culture bias

A tendency to interpret all phenomena through the lens of ones’s own culture, ignoring the effects that cultural differences might have on behaviour

Gender bias

Psychological research or theory may offer a view that does not justifiably represent the experience and behaviour of men or women.

Bias

A tendency to treat one individual or group in a different way than others

W Co-morbidity

If 2 MHCs co-occur in different people then it calls the validity of the diagnosis into question as schizophrenia and depression might be a single condition.

Schizophrenia is commonly diagnosed with other conditions.

Buckley - 50% of people with schizophrenia also have depression, 47% had a substance abuse and 23% had OCD.

Problem for diagnosis as at least some people diagnosed with both schizophrenia and depression may just have an unusual case of depression.

W Culture bias

Symptoms of schizophrenia like hearing voices have different meanings and are more accepted in different cultures.

In some African-Caribbean societies - voices = communications from ancestors.

British-African-Caribbeans - 9x more likely to have a schizophrenia diagnosis than white British people.

African-Caribbean origin living in African-Caribbean countries - Not such a high level - rules out genetic vulnerability.

This difference may happen as British psychiatrists misinterpret symptoms in African-Caribbean-British people.

Suggests that these people may be discriminated by a culturally-biased diagnostic system.

W Gender bias

Men diagnosed more commonly than women 1.4:1 ratio.

A possible explanation is that women are less vulnerable than men due to of genetic factors.

More likely that women are undiagnosed as they have closer relationships and better support. So women with schizophrenia often appear to function better than men.

This underdiagnosis is a gender bias and means women may not get treatment or beneficial services.

W Symptom overlap with other conditions

Schizophrenia and bipolar disorder can involve positive symptoms like delusions. Less severe in bipolar disorder so isn’t a requirement for diagnosis.

It can be difficult to decide whether a person with delusions should be diagnosed with schizophrenia or bipolar disorder. This calls into question the value of a diagnosis.

Suggests that it might be better to focus on distinct symptoms rather than looking at conditions which aren’t that different

S Reliability

Osório

A diagnosis is reliable when different diagnosing clinicians reach the same diagnosis for the same person (inter-rater reliability)

Reported excellent reliability for the diagnosis of schizophrenia in 180 people using the DSM-5. Pairs of interviewers achieved inter-rater reliability of +.97 and test-retest reliability of +.92

Suggests that we can be sure that the diagnosis of schizophrenia is consistently applied.