Assessment and Treatment of Psychosis in Adolescents

Critical First Steps: Substance Use Assessment and Cessation

The American Academy of Child and Adolescent Psychiatry recommends that cannabis use be discontinued immediately in adolescents presenting with psychotic symptoms, as it can both mimic and exacerbate psychotic symptoms, particularly in vulnerable adolescents with a family history of schizophrenia 1, 2
A toxicology screen should be obtained to confirm marijuana use and rule out other substances of abuse that can cause psychotic symptoms, according to the American Academy of Child and Adolescent Psychiatry 1, 2
Cannabis-induced psychosis can be indistinguishable from primary psychotic disorders at initial presentation, requiring a period of abstinence to clarify the diagnosis, as noted by the American Academy of Child and Adolescent Psychiatry 1

A detailed psychiatric assessment, including symptom presentation, course of illness, mental status examination, and family psychiatric history, is necessary to determine the underlying cause of psychotic symptoms in adolescents, as recommended by the American Academy of Child and Adolescent Psychiatry 3, 2
A physical examination and medical workup, including complete blood count, serum chemistry, thyroid function, urinalysis, and neuroimaging if necessary, should be conducted to rule out organic causes of psychosis, according to the American Academy of Child and Adolescent Psychiatry 1, 4
A developmental and functional assessment should be performed to determine if there has been deterioration from previous baseline functioning, as recommended by the American Academy of Child and Adolescent Psychiatry 3, 2

The American Academy of Child and Adolescent Psychiatry suggests waiting 4-6 weeks after marijuana cessation before making a definitive diagnosis of schizophrenia, as substance-induced psychotic symptoms may resolve spontaneously 1
During this observation period, the patient should be monitored for persistence of psychotic symptoms, which would support a primary psychotic disorder rather than substance-induced psychosis, as noted by the American Academy of Child and Adolescent Psychiatry 1

If schizophrenia is confirmed after substance cessation and completion of the diagnostic evaluation, the American Academy of Child and Adolescent Psychiatry recommends considering antipsychotic medication, starting with an atypical antipsychotic such as risperidone or olanzapine 3, 5
The medication should be started at a low dose and titrated slowly over several weeks to minimize side effects while achieving therapeutic benefit, as recommended by the American Academy of Child and Adolescent Psychiatry 5, 6
An adequate therapeutic trial requires 4-6 weeks at sufficient dosage before determining efficacy, according to the American Academy of Child and Adolescent Psychiatry 5, 6

The American Academy of Child and Adolescent Psychiatry recommends obtaining informed consent from the parent/guardian and assent from the adolescent before starting antipsychotic medication, and documenting baseline weight, metabolic parameters, and any movement abnormalities 5, 6
The patient should be monitored regularly for extrapyramidal side effects, weight gain, and metabolic changes, and for substance use relapse, which is a major risk factor for treatment failure, as noted by the American Academy of Child and Adolescent Psychiatry 5, 6

The American Academy of Child and Adolescent Psychiatry warns against starting antipsychotics while the patient is actively using marijuana, as this obscures the diagnosis and marijuana use alone can cause treatment failure, and against assuming schizophrenia diagnosis without ruling out substance-induced psychosis 1
Bipolar disorder should not be overlooked, as approximately 50% of adolescents with bipolar disorder are initially misdiagnosed as having schizophrenia, and mania in teenagers often presents with florid psychosis, according to the American Academy of Child and Adolescent Psychiatry 7, 1

The American Academy of Child and Adolescent Psychiatry recommends that substance abuse treatment be the immediate priority and must be addressed before or concurrent with any other intervention, and that psychosocial interventions such as social skills training and relapse prevention strategies should accompany any treatment plan 3, 5
Specialized educational support should be provided to address any cognitive or functional deficits, as recommended by the American Academy of Child and Adolescent Psychiatry 5