A scoping review of amenable patient-specific predictors of treatment failure in the treatment of anxiety and depressive disorders

Background By identifying predictors of treatment failure that are susceptible to change (amenable), we can move towards studying ways to decrease the odds of treatment failure, e.g., by targeting these predictors before treatment, adapting interventions, accordingly, choosing more suitable treatments, or preparing patients better for psychotherapy. While treatment success, within anxiety and depressive disorders, has been studied extensively, it seems that treatment failure is overlooked, even while we know that about one third of the treatment population shows no benefit in treatment. Method In order to review the available body of knowledge concerning amenable patient-specific predictors for treatment failure, we conducted a literature search in PubMed, PsycInfo, Embase, and Medline, following the Prisma-ScR guidelines. Thirty articles met the inclusion criteria and are summarized in this review. Conclusions were drawn for scientific and clinical implications. Results Predictors of treatment failure that are replicated or are significant in multiple studies are low treatment expectancy, high neuroticism, low use of social support, low outcome expectancy, and low perceived social support. Treatment failure is hard to define, and very few studies are replicated. There are predictors that are studied in multiple articles, but they are measured with different instruments, or in very small or specific patient samples, therefore it is difficult to compare findings from different studies. Conclusions There are no predictors that stand out as overall strong amenable predictors of treatment failure. Possible predictors are high neuroticism, low treatment expectancies, and low use of social support. Future research should focus on replicating studies to confirm these predictors of treatment failure.