Unraveling Relapse in Male Forensic Psychiatric Patients with Substance Use Disorders—The Impact of Social, Psychiatric, and Personality Factors Post Long-Term Remission

Abstract Substance use disorder, labelled a chronic relapse condition by the WHO, remains challenging to address with limited progress in effective relapse prevention measures. Scientific evaluation is hindered by cost, but an opportunity arises in the German forensic psychiatric setting governed by § 64 of the German criminal code. Here, patients undergo two-year multi-modal therapy followed by up to five years of supervised oversight post-release. This retrospective study analyzed legal and medical records, revealing key determinants of relapse, including emotional stress, social activities, personality disorder diagnosis, inpatient treatment relapse, age at first conviction, and loss of motivation. Surprisingly, social factors like family and work status, living situation at discharge, and dialectical behavioral therapy during admission showed no impact, nor did index crime type. Polysubstance use, except for cannabinoids and psychostimulants other than cocaine, increased relapse probability. Multiple inpatient pretreatments were insignificant predictors. A generalized linear model highlighted substance use during inpatient treatment, personality disorder, and previous convictions as most central predictors of post-discharge relapse, challenging conventional notions and informing effective substance use disorder management.