2 symptoms for at least 1 month with signs of

2 symptoms for at least 1 month, with signs of continuous disturbance for 6 months
“Positive” symptoms
1. hallucinations (false perceptions)
2. Delusions (false beliefs)
3. Disorganized speech (derailment, incoherence, loose associations)
4. Disorganized behavior (e.g., disheveled appearance)
“Negative” symptoms
▶ flat affect (lack of emotion)
▶ reduction in speech quality
▶ mental confusion
▶ lack of energy/initiative
▶ Diagnosis also requires significant decrease in functioning or failure to make expected
gains
Prevalence and Course
• Rare in children less than 12 age
• Increased prevalence in adolescence and early adulthood
• average age onset 20-25
• COS: boys > girls, difference disappears in adolescence
• Gradual onset: ~ 95% show a clear history of disturbances prior to onset of psychosis
• speech language problems
• poor motor development
• movement abnormalities
• social skills deficits

• odd behavior (suspicion/paranoia)
• substance abuse
• childhood onset of schizophrenia indicates a more severe form of the disorder
• Chronic disorder with poor long-term prognosis
• Prevalence rates of adult schizophrenia similar across cultural groups and countries
• COS is distinct from transient psychotic symptoms
Causes of COS
• Strong genetic contribution (80% heritability)
• Neurodevelopmental model
– Genetic vulnerability +prenatal insult
defective neural circuitry, which is vulnerable to dysfunction under stress & developmental
changes
• Exaggerated cortical gray matter loss during adolescence
• Pattern eventually mimics that seen in adult-onset cases
• temporal (attention and perception) and prefrontal lobe (organizing, planning, problem-
solving) gray matter reductions.
Family Influences
exposure to a stressful family environment + genetic risk increases risk for developing COS
Parents of children with COS are more critical
parents of those with COS score higher on communication deviance =
interpersonal signs of attentional and thought disturbance.
Treatment of COS
• Primary treatment: anti-psychotic medications (dopamine antagonists – block dopamine
transmission)
– reduce hallucinations and delusions

– negative symptoms often endure – predict poor quality of life
– adverse effects reduce adherence to treatment and require constant monitoring
• Weight gain
• Metabolic changes (cholesterol, prolactin)
• Sedation
• Neurological side effects
– Akathisia – inner restlessness inability to sit still
– Other long-term motor side effects (tremor, tardive dyskinesia)
• Treatment guidelines emphasize the use of antipsychotic medications combined with
psychosocial treatments
– family intervention
– social skills training