Background and Hypothesis Based on the need-adapted approach, delaying antipsychotics could help identify first-episode psychosis adolescents who might not require them. However, some individuals might need antipsychotics, and postponing could harm their prognosis. This nationwide register-based follow-up aimed to test these two hypotheses.

Study Design All adolescents aged 13-20 with a psychotic disorder (ICD-10 codes: F20-F29) in Finland between 2003-2013 were identified (n=6,354) from national registers. For each case, a fixed 1825-day follow-up period was established from the onset of psychosis or until death. The outcome was considered "good" if adolescents did not die and had not received psychiatric treatment and/or disability allowances during the final year of follow-up. Testing the first hypothesis involved all antipsychotic treatment-naïve adolescents with first-episode psychosis (n=3714). The second hypothesis was tested with a sub-sample of only those who had received antipsychotics during follow-up (n=3258). To account for baseline confounders, hypotheses were tested via a stabilized inverse probability of treatment weighted generalized linear models with logit link function.

Study Results Immediate antipsychotic treatment after the onset of psychosis was associated with poor five-year outcome (adjusted odds ratio [aOR]: 1.8, 95% CI: 1.6-2.1). There was no statistically significant association between antipsychotic postponement and treatment outcome in those who eventually received antipsychotic treatment (aOR: 1.02, 95%CI: 0.7-1.2, p: 0.8), thus not providing support for second hypothesis.

Conclusions There is a significant subgroup of adolescent with psychosis who do not require immediate antipsychotic treatment. A more robust design is needed to evaluate the causality of the observed association.