Use and discontinuation of antipsychotic medication in 20 years following a first episode of schizophrenia: results from the OPUS trial

Introduction. Short-term exposure to antipsychotics has proven to be beneficial. However, naturalistic studies are lacking regarding the long-term use of antipsychotics. This study aimed to investigate changes in use of antipsychotics over 20 years after a first-episode schizophrenia. Methods. This study is part of the Danish OPUS trial (1998-2000), including 496 participants with first-episode schizophrenia. Participants were reassessed four times over 20 years. The main outcomes were days on medication, redeemed prescriptions of clozapine, psychiatric hospitalizations, and employment. Results. At the 20-year follow-up, an attrition of 71% was detected. In total, 143 out of 496 participated, with 36% (n = 51) in remission-of-psychotic-symptoms-off-medication. The lowest number of days on medication (mean [S.D.], 339 [538] days) was observed in this group over 20 years. Register data on redeemed antipsychotics were available for all trial participants (n = 416). Individuals in treatment with antipsychotics (n = 120) at the 20-year follow-up had spent significantly more days in treatment (5405 [1857] v. 1434 [1819] mean days, p = 0.00) and more had ever redeemed a prescription of clozapine (25% v. 7.8%, p = 0.00) than individuals who had discontinued antipsychotics (n = 296). Further, discontinuers had significantly higher employment at the 20-year follow-up (28.4% v. 12.5%, p = 0.00). Conclusion. In a cohort of individuals with first-episode schizophrenia, 36% were in remission-of-psychotic-symptoms-off-medication. However, high attrition was detected, potentially affecting study results by inflating results from individuals with favorable outcomes. From register data, free from attrition, approximately 30% were in treatment with antipsychotics, and 70% had discontinued antipsychotics. Individuals in treatment had the least favorable outcomes, implying greater illness severity.