The impact of psychopathological subtypes on retention rate of patients with substance use disorder entering residential therapeutic community treatment

BACKGROUND A specific psychopathology of addiction has been proposed and described using the self-report symptom inventory (SCL-90), leading to a 5-factor aggregation of psychological/psychiatric symptoms: 'worthlessness and being trapped', 'somatic symptoms', 'sensitivity-psychoticism', 'panic-anxiety' and 'violence-suicide' in various populations of patients with heroin use disorder (HUD) and other substance use disorders (SUDs). These clusters of symptoms, according to studies that have highlighted the role of possible confounding factors (such as demographic and clinical characteristics, active heroin use, lifetime psychiatric problems and kind of treatment received by the patients), seem to constitute a trait rather than a state of the psychological structure of addiction. These five psychopathological dimensions defined on the basis of SCL-90 categories have also been shown to be correlated with the outcomes of a variety of agonist opioid treatments. The present study aims to test whether the 5-factor psychopathological model of addiction correlates with the outcome (retention rate) of patients with SUDs entering a therapeutic community (TC) treatment. METHODS 2016 subjects with alcohol, heroin or cocaine dependence were assigned to one of the five clusters on the basis of the highest SCL-90 factor score shown. Retention in treatment was analysed by means of the survival analysis and Wilcoxon statistics for comparison between the survival curves. The associations between the psychopathological subtypes defined by SCL-90 categories and length of retention in treatment, after taking into account substance of abuse and other sociodemographic and clinical variables, were summarized using Cox regression. RESULTS Patients with cocaine use disorder (CUD) showed poorer outcomes than those with heroin dependence (HUD). Prominent symptoms of "worthlessness-being trapped" lead to a longer retention in treatment than in the case of the other four prominent psychopathological groups. At the multivariate level, age, detoxified status and total number of psychopathological symptoms proved to influence outcome negatively, especially in CUD. Somatic symptoms and violence-suicide symptoms turned out to correlate with dropout from residential treatment. CONCLUSIONS The SCL-90 5-factor dimensions can be appropriately used as a prognostic tool for drug-dependent subjects entering a residential treatment.