Factors associated with relapse in schizophrenia despite adherence to long-acting injectable antipsychotic therapy

• Published in: International clinical psychopharmacology Vol. 31; no. 4; p. 202
• Main Authors: Alphs, Larry, Nasrallah, Henry A, Bossie, Cynthia A, Fu, Dong-Jing, Gopal, Srihari, Hough, David, Turkoz, Ibrahim
• Format: Journal Article
• Language: English
• Published: England 01.07.2016
• Subjects: Adolescent; Adult; Antipsychotic Agents - administration & dosage; Antipsychotic Agents - therapeutic use; Delayed-Action Preparations - administration & dosage; Double-Blind Method; Female; Humans; Injections, Intramuscular; Internationality; Male; Medication Adherence; Recurrence; Risperidone - administration & dosage; Schizophrenia - diagnosis; Schizophrenia - drug therapy; Young Adult
• ISSN: 1473-5857
• DOI: 10.1097/YIC.0000000000000125

Many patients with schizophrenia will relapse despite uninterrupted antipsychotic (AP) long-acting therapy (LAT). This exploratory analysis examined variables associated with relapse despite ensured adherence to LAT. This was a post-hoc exploratory analysis of a 1-year study of risperidone long-acting injection in patients with stable schizophrenia or schizoaffective disorder (NCT00297388; N=323). Patients were discontinued from previous oral APs and randomly assigned to biweekly intramuscular injections of risperidone long-acting injectable 50 (n=163) or 25 mg (n=161) for 52 weeks. Cox proportional hazards regression models examined variables putatively associated with relapse. A total of 59/323 (18.3%) patients relapsed over 12 months despite continuous AP LAT. Variables associated with the risk of relapse included illness duration (6.0% increase each year; P=0.0003) and country (Canada vs. USA, 4.7-fold risk increase; P=0.0008). When illness duration was further categorized as ≤5, 6-10, and >10 years, patients with an illness duration of >10 versus ≤5 years were at greatest risk of relapse (>10 vs. ≤5 years associated with a 4.4-fold increase in the risk of relapse; P=0.0181). Findings suggest that patients with more chronic illness have a greater risk of relapse despite ensured treatment adherence, supporting the need for early intervention to prevent the deleterious effects of chronicity.