Long-term Amelioration of OCD Symptoms in a Patient with Chronic Consumption of Psilocybin-containing Mushrooms

Introduction

Obsessive Compulsive Disorder (OCD) is described as a chronic neuropsychiatric disorder marked by intrusive thoughts and repetitive behaviours that impair daily functioning, with a lifetime prevalence of about 2–3%. First-line treatments, principally selective serotonin reuptake inhibitors (SSRIs), fail to produce adequate response in an estimated 41–43% of patients, leaving a substantial treatment-resistant population. Previous case reports and some experimental data have suggested that psilocybin and psilocybin-containing mushrooms may reduce OCD symptomatology, but evidence remains limited and heterogeneous. This paper presents a single-case report of an adult male with long-standing, treatment-resistant OCD who experienced a clinically meaningful reduction in symptoms following consumption of psilocybin-containing mushrooms. The aim is to document the clinical course, measured symptom change, and tolerability in this individual, and to situate the observation within existing animal and human findings about serotonergic mechanisms and psychedelic compounds in OCD treatment.