Which aspects of long-term outcome are predicted by positive and negative symptoms in early-onset psychosis? An exploratory eight-year follow-up study.

Background: Early-onset psychoses show substantial variability of diagnostic and functional outcome. Finding reliable prognostic factors may allow to allocate resources to those with the worst prognosis. The aim of the study was to gain new insights regarding the potential value of baseline negative and positive symptoms as predictors of outcome in psychoses of early onset.

Method: Sixty-three patients with early-onset schizophrenia spectrum psychosis hospitalized in an adolescent psychiatry unit were assessed with the Positive and Negative Syndrome Scale during the index admission. Associations with diagnosis, illness course and functional outcome were analysed in mean 8 years of follow-up (range 3.4-13.5 years).

Results: The mean age at the index admission and the follow-up was 16.6 ± 1.2 and 24.5 ± 3.0 years, respectively. A significant majority of subjects continued psychiatric treatment (95%) and had been readmitted (71%). The mortality rate was 3% (suicide and accident). Negative symptoms were related to mental health service utilization during the follow-up. General severity of symptoms, specifically positive and cognitive factors were associated with the diagnosis of schizophrenia and inversely with diagnostic shift outside the schizophrenia spectrum at the catamnesis. Poor impulse control at baseline was associated with worse functional outcome. The drug-free subgroup with no occupational/educational activity compared with the drug-treated subjects showed lower levels of baseline negative symptomatology.

Conclusion: The study findings suggest that in patients with early-onset psychosis negative and positive symptoms show a differential prognostic value. Pharmacotherapy may attenuate the effect of symptoms on functional outcome. These hypotheses need to be tested in future studies using confirmatory approaches.