Schizophrenia: Symptoms and Features

Question 1

How is schizophrenia diagnosed?

Answer 1

DSM-5
- requires at least two of the four key symptoms listed below.
- The person must have at least one month of active symptoms and six months of disturbance to everyday functioning.

ICD-10
- less focus on dysfunction and six months of disturbance is not necessary. Six subtypes are listed.

Question 2

What are the four key symptoms of schizophrenia?

Answer 2

• Thought insertion
• Hallucinations
• Delusions
• Disorganised thought

THHallDelDis

Question 3

What are thought inversions?

Answer 3

• A person believes their thoughts do not belong to them and have been implanted by an external source.
• Experience ‘blurring’ between self and others.

Question 4

What are hallucinations?

Answer 4

• Involuntary and vivid perceptual experiences that occur in the absence of external stimuli.
• Visual, olfactory (smell), somatosensory (bodily feelings).
• Auditory are most common in schizophrenia (experienced as hearing voices, distinct from one’s own inner voice/thoughts).

Question 5

What are delusions?

Answer 5

• ‘Fixed beliefs that are not amenable to change in the light of conflicting evidence’ (DSM-5).
• May relate to everyday life, or may be ‘bizarre’.
• Many forms, e.g. persecutory (someone is trying to harm you), referential (environmental cues have personal meanings) and/or grandiose (you are exceptional).

Question 6

What are disorganised thoughts?

Answer 6

• Inferred from speech - derailment (unrelated ideas) or tangentiality (going off on a different topic).
• Difficult to follow the person’s train of thought.
• ‘Word salad’ (random stringing together of words), ‘neologism’ (blending words to create new words).
• Mixing up words is common so this is only classed as symptomatic if it leads to dysfunctional communication.

Question 7

What is the prevalence of schizophrenia? (how frequent, what age)

Answer 7

• Lifetime prevalence is 0.3-0.7% (varies with ethnicity, nationality and geographic origin in immigrants).
• Onset is slightly earlier in males (early- to mid-20s) than females (late-20s) and males have a poorer prognosis.