Not Two Sides of the Same Coin: A Qualitative Comparative Analysis of Post-Treatment Abstinence and Relapse

Substance use disorder (SUD) can be a chronic relapsing condition with poor treatment outcomes. Studies exploring factors associated with abstinence or relapse after treatment are often quantitative in nature, applying linear statistical approaches, while abstinence and relapse result from non-linear, complex, dynamic and synergistic processes. This study aims to explore these underlying dynamics using qualitative comparative analysis (QCA) as a mixed methods approach to further our understanding of factors contributing to post-treatment abstinence and relapse.

In a prospective study, we gathered both qualitative and quantitative data pertaining to post-treatment substance use and the factors linked to substance use outcomes. These factors encompassed psychiatric comorbidity, intellectual disability, social disintegration, post-treatment support, and engagement in activities among patients who had undergone inpatient treatment for severe SUD (n = 58). QCA, a set-theoretic approach that considers the complex interplay of multiple conditions, was applied to discern which factors were necessary or sufficient for the occurrence of either abstinence or relapse.

We found two solutions predicting abstinence, and five for relapse. Post-treatment conditions (support and engagement in activities) were important for retaining abstinence. For relapse, individual baseline characteristics (intellectual disability, social disintegration, psychiatric comorbidity) combined with (post-)treatment factors (post-treatment support, activities) were important.

Although abstinence and relapse represent opposing outcomes, they each exhibit distinct dynamics. To gain a comprehensive understanding of these dynamics, it is advisable to examine them as separate outcomes. For clinical practice, it can be worthwhile to recognize that fostering the conditions conducive to abstinence may differ from preventing the factors that trigger relapse.