Psychosocial Factors Influencing Adherence to Mental Health Treatments: A Health Behavior–Based Theoretical Model

Abstract

This study aimed to explain mental health service users’ experiences of the psychological, social, relational, and structural determinants of treatment continuation and to develop a theoretical model grounded in health behavior frameworks. A qualitative design using thematic analysis was employed. The participants were 24 adults receiving outpatient mental health services in Tehran, Iran. They were recruited through purposive maximum-variation sampling according to age, gender, diagnosis, treatment modality, and duration of treatment. Data were collected exclusively through individual semi-structured interviews. Interviews continued until theoretical saturation was achieved; preliminary saturation occurred after the twenty-first interview, and three additional interviews were conducted to confirm the comprehensiveness and stability of the categories. Interviews were transcribed verbatim and analyzed through iterative coding, constant comparison, category development, and thematic integration using NVivo 14. Credibility and dependability were enhanced through member checking, peer debriefing, maximum-variation sampling, maintenance of an audit trail, and comparison of emerging interpretations with negative or divergent cases. Five main categories were identified: “illness- and treatment-related beliefs and literacy,” “emotional and motivational self-regulation,” “therapeutic alliance and experienced autonomy,” “family context, social support, and stigma,” and “economic, organizational, and everyday feasibility of treatment.” Adherence was not experienced as a stable personal attribute or a simple outcome of willpower. Rather, it emerged as a dynamic and recursive process shaped by perceived treatment necessity, concerns about adverse effects, hope, self-efficacy, symptom fluctuations, trust in professionals, shared decision-making, family responses, anticipated stigma, treatment costs, accessibility, and continuity of care. The findings supported a theoretical model conceptualizing adherence as “relationally supported and practically feasible self-regulation.” In this model, psychological capability, social and structural opportunity, and autonomous motivation jointly influence the initiation and maintenance of treatment behaviors. Changes in symptoms and treatment experiences subsequently produce feedback that may strengthen or weaken future adherence. Effective adherence interventions should therefore move beyond patient education or reminders alone and combine personalized mental health literacy, autonomy-supportive communication, shared decision-making, a strong therapeutic alliance, appropriately structured family involvement, stigma reduction, and improved financial and organizational access to care.