Diagnostic Criteria for Schizophrenia and Schizoaffective Disorder

Core Diagnostic Requirements

The American Academy of Child and Adolescent Psychiatry recommends that schizophrenia requires at least two psychotic symptoms present for a significant portion of one month, with only one symptom needed if delusions are bizarre or hallucinations involve running commentary or conversing voices 1, 2
The American Academy of Child and Adolescent Psychiatry suggests that schizophrenia requires a duration of continuous disturbance for at least 6 months, including at least 1 month of active symptoms, and social/occupational dysfunction must be markedly below previous levels 1, 2
The American Academy of Child and Adolescent Psychiatry states that mood symptoms, if present, must be brief relative to the total duration of psychotic illness in schizophrenia 1, 2
The American Academy of Child and Adolescent Psychiatry recommends that schizoaffective disorder requires at least 2 weeks of psychotic symptoms persisting in the absence of prominent mood symptoms during the same continuous period of illness 1

The American Academy of Child and Adolescent Psychiatry suggests that a complete medical workup is mandatory before assuming primary psychiatric disorder, with approximately 20% of acute psychosis cases having medical causes 2
The Journal of the American Academy of Child and Adolescent Psychiatry recommends obtaining thorough pediatric and neurological evaluation, including physical examination, complete blood count, chemistry panel, thyroid function, toxicology screening, and neuroimaging/EEG when clinically indicated 3, 4, 2

The American Academy of Child and Adolescent Psychiatry recommends that antipsychotic medications are first-line treatment for schizophrenia, with atypical antipsychotics preferred over traditional neuroleptics for equivalent efficacy on positive symptoms with better tolerability 1, 2
The American Academy of Child and Adolescent Psychiatry suggests that adequate therapeutic trials require sufficient dosages over 4-6 weeks before concluding treatment failure 1
The American Academy of Child and Adolescent Psychiatry recommends that clozapine is reserved for treatment-resistant cases after failure of at least two other antipsychotics (at least one should be atypical) 1, 2

The Journal of the American Academy of Child and Adolescent Psychiatry states that onset before age 10 is uniformly associated with poor outcome 7
The Journal of the American Academy of Child and Adolescent Psychiatry suggests that insidious onset (over more than 4 weeks) predicts greater disability 7
The Journal of the American Academy of Child and Adolescent Psychiatry recommends that family psychiatric history may help differentiate: increased family history of mood disorders suggests schizoaffective or bipolar disorder 6, 5