Schizophrenia

• Schizophrenia has an incidence rate of 1% worldwide.
• The typical age of onset for schizophrenia is late teens to early 20s.
• Schizophrenia affects men and women equally.
• Schizophrenia is a psychotic disorder characterised by a loss of contact with reality.
• Schizophrenia has two types of symptoms, positive and negative.
• Positive symptoms in schizophrenia are behaviours and disturbances which schizophrenics have whilst non-schizophrenic do not, and often improve or disappear with medication.
• Hallucinations in schizophrenia are perceiving stimuli which other people do not perceive, most commonly auditory hallucinations (hearing voices), and less often visual hallucinations.
• Delusions in schizophrenia are having beliefs which other people do not share, these might be delusions of grandeur (‘I am Jesus’), or paranoid delusions (‘The CIA is out to get me’).
• Classification systems have become more reliable over time.
• One hundred Danish patients with a history of psychosis were assessed using operational criteria, finding a concordance rate of 98%, demonstrating the high reliability of clinical diagnosis of schizophrenia using up-to-date classifications.
• Beck et al (1962) reported a 54% concordance rate between experienced practitioners’ diagnoses when assessing 153 patients.
• Jakobsen et al (2005) tested the reliability of the ICD-10 classification system in diagnosing schizophrenia.
• Söderberg et al (2005) reported an 81% concordance rate using the DSM classification system.
• A diagnosis is reliable if, given the same symptoms, the same diagnosis is made.
• Nilsson et al (2000) found only a 60% concordance rate between practitioners using the ICD classification system, implying the DSM system is more reliable.
• ICD-10 includes diagnoses such as thought echo, thought insertion/withdrawal, passivity, delusional perception, and third person auditory hallucinations, running commentary.
• Negative symptoms in schizophrenia are behaviours and disturbances resulting from something schizophrenics lack compared to non-schizophrenics, and do not respond well to medication.
• Anhedonia in schizophrenia is the lack of pleasure in activities they would normally enjoy.
• Flat affect in schizophrenia is the lack of, or inappropriate, emotions.
• Alogia in schizophrenia is the lack of, or poverty of, speech.
• Avolition in schizophrenia is a lack of motivation.
• Catatonia in schizophrenia is a lack of movement.
• Schizophrenia is divided into Type I and Type II.
• Type I schizophrenia is an acute type, often appearing quickly and characterised by positive symptoms.
• Type II schizophrenia is a chronic type, where symptoms appear gradually and are more likely to be negative symptoms.