Psychodynamic Psychotherapy for Obsessive-Compulsive Disorder: A Single-Case Report with Quantified Outcomes

: Obsessive-compulsive disorder (OCD) remains a disabling condition for a subset of patients who fail to respond to first-line behavioral protocols. We report a measurement-informed psychodynamic psychotherapy case of an adult with DSM-5 OCD characterized by harm- and contamination-related intrusions with checking/washing rituals. The patient received psychodynamic treatment using clarification, confrontation, and interpretation, focused on defenses of isolation of affect, undoing, and intellectualization. Outcomes were tracked with gold-standard metrics. Obsessive-compulsive severity improved from Y-BOCS 26 (baseline) to 16 (posttreatment) (Δ = 10; -38.5%), meeting conventional response thresholds; GAF rose from 58 to 70 (Δ = +12). Dimensional burden (DOCS) decreased from 56 at baseline to 41 at a 24-month delayed follow-up, suggesting durability. No adverse events occurred. This case illustrates how psychodynamic psychotherapy for OCD could be paired with systematic outcome monitoring. Observed mechanisms of change include increased affect tolerance, reduced reliance on isolation/undoing, and enhanced capacity to mentalize conflict-laden meanings, with reductions in ritualizing and avoidance. Larger multicenter cohorts and manualized treatment trials are warranted to define effectiveness and mechanisms of change relative to exposure-based and combined integrative approaches.