How Self-Determination Theory can contribute to the assessment of motivation in patients with schizophrenia: A narrative review.

Motivation is one of the important determinants of functional outcomes in schizophrenia, yet its conceptualization and measurement remain heterogeneous. The literature reflects two predominant orientations: a psychiatric (nosological) perspective which construes motivation primarily as a deficit linked to negative symptoms, and a psychological perspective, mostly grounded in Self-Determination Theory (SDT), which emphasizes intrinsic motivation, the quality of regulation, and the satisfaction of basic psychological needs - autonomy, competence, and relatedness. Psychiatric approaches often conflate symptoms and motivational states and lack specificity regarding the object of motivation (e.g., goals, tasks, social engagement), whereas SDT brings to light environmental and interpersonal determinants. Although both approaches document altered motivational profiles, intermediate forms of regulation and context-specific motivations remain underexplored. This narrative review synthesizes these perspectives, examines measurement approaches, and argues that integrating SDT principles can refine assessment, clarify mechanisms, and inform interventions to enhance engagement, well-being, and functional recovery in schizophrenia.