Only 19.1% of First-Episode Psychosis Patients Adhere to Antipsychotics
Key Clinical Summary
- Among 11,889 commercially insured US patients with first-episode psychosis, 19.1% met the study’s threshold for antipsychotic adherence during 12 months of follow-up.
- Greater adherence was associated with fewer emergency department visits and more behavioral health and general outpatient visits.
- Antipsychotic adherence was not significantly associated with psychiatric or general hospitalization.
Young people beginning antipsychotic treatment after first-episode psychosis had low medication adherence, according to a retrospective US cohort study published in JAMA Network Open.
Patients classified as treatment-adherent had fewer emergency department visits and greater outpatient health care utilization, although adherence was not significantly associated with hospitalization.
Study Findings
Researchers analyzed Merative MarketScan commercial insurance claims from January 2013 through December 2021. The study cohort included 11,889 patients aged 15 to 40 years with 12 months of continuous enrollment who had no prior diagnosis of psychosis, who subsequently experienced first-episode psychosis and began antipsychotic treatment.
The patients’ mean age was 22.7 years, and 56.4% were male. Schizophrenia spectrum disorders accounted for 43.0% of diagnoses, mood disorders with psychotic features accounted for 42.5%, and other psychotic spectrum disorders accounted for 14.5%.
Adherence was assessed over 365 days using the proportion of days covered. Patients with medication available for at least 80% of that period were classified as adherent. Overall, patients had antipsychotic medication available for 43.3% of follow-up days, or 158 of 365 days, and 19.1% met the adherence threshold.
Adherence rates were 23.1% among patients with schizophrenia spectrum disorders, 16.9% among those with mood disorders with psychotic features, and 13.5% among those with other psychotic spectrum disorders.
Adherence was associated with fewer emergency department visits (incidence rate ratio [IRR] 0.85; 95% confidence interval [CI], 0.81–0.90; P < .001). It was also associated with more behavioral health outpatient visits (IRR, 1.53; 95% CI, 1.47–1.59; P < .001) and general outpatient visits (IRR, 1.07; 95% CI, 1.02–1.13, P = .003). No statistically significant associations were identified for psychiatric or general hospitalization
Clinical Implications
The findings identify low antipsychotic adherence as a potential challenge during the early course of psychosis. The observed association between adherence, greater outpatient engagement, and fewer emergency department visits supports attention to treatment continuity after antipsychotic initiation.
Long-acting injectable antipsychotic use was uncommon: 0.5% of patients received injectable formulations exclusively, while 3.9% received both oral and injectable formulations. However, the small numbers prevented robust analyses of their use.
The results should not be interpreted as establishing causality. Prescription claims indicate that medication was available, not that patients took it as prescribed. The database also excluded publicly insured patients and could not fully capture medications obtained outside insurance claims or administered during hospitalization.
Expert Commentary
Regarding the sensitivity analysis, “low antipsychotic adherence does not necessarily reflect complete disengagement from medication treatment,” wrote corresponding author Eric E. Seiber, PhD, College of Public Health, The Ohio State University, Columbus, Ohio, and study coauthors. Adherence reached 32.7% when antidepressants and mood stabilizers were included with antipsychotics.
The researchers called for further study of medication trajectories during early psychosis. Their findings suggest that improving antipsychotic treatment continuity and outpatient engagement may help reduce reliance on emergency services, while underscoring the need for research beyond commercially insured populations.
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