Baseline Antipsychotic Dose Predicts Conversion to Psychosis

TOPLINE:

Initiation of a high- vs low- baseline dose of an antipsychotic is tied to an elevated risk for psychosis conversion in high-risk patients, data from a new meta-analysis confirmed.

METHODOLOGY:

Investigators analyzed data from eight studies including 290 people at high-risk for psychosis who took antipsychotics at baseline.Each study included detailed information on medication dosage — provided in terms of chlorpromazine equivalent doses (CPZ-ED) — and information about subsequent transition to psychosis.The mean age of the sample was 19 years, and of 290 people, 66 transitioned to psychosis.

TAKEAWAY:

The mean CPZ-ED received by individuals who transitioned to psychosis was 161.5 mg/d (range, 60-395 mg/d) compared with 115.7 mg/d (range, 13-224 mg/d) in those who did not convert.Among those exposed to antipsychotics at baseline, those at risk for psychosis received higher doses than those who did not convert (Hedges g, 0.41; P=.005) by the follow-up periods.Investigators noted that the minimum CPZ-ED effective for acute schizophrenia was approached more often in those who converted to psychosis than in those who did not, and some of those who converted were plausibly exposed to dosages that are deemed effective in controlling psychotic symptoms (150-200 mg/d).The findings confirm that a fraction of individuals at high risk for psychosis, despite belonging to stage 1b of the clinical staging model of psychosis, are being treated as though they are at stage 2 (ie, first episode psychosis), the authors noted.

IN PRACTICE:

The findings confirm “that baseline pharmacological treatment is a widely neglected yet relevant prognostic modulator that might mask the potential effectiveness of some of the treatments currently prescribed to individuals at high risk for psychosis who are seeking treatment,” study authors wrote.

SOURCE:

Andrea Raballo, MD, PhD, of the Università della Svizzera Italiana, in Lugano-Viganello, Switzerland, led the study, which was published online March 20, 2024, in JAMA Psychiatry.

LIMITATIONS:

The studies included in the analysis did not systematically detail baseline psychopathological information for those who converted to psychosis and those who did not.