Trauma-related pathways in obsessive-compulsive disorder: A systematic review of aetiology, symptom dimensions and severity

BACKGROUND: Accumulating evidence suggests traumatic life experiences could influence the onset, symptomatology, and severity of Obsessive Compulsive Disorder (OCD). However, comprehensive insights into the relationship between trauma and OCD remain fragmented. OBJECTIVES: To systematically examine the relationship between trauma and OCD across three critical domains: (1) the role of trauma in the aetiology of OCD; (2) the associations between specific trauma types and distinct OCD symptom dimensions; and (3) the impact of trauma on OCD severity and comorbid psychopathologies. METHODS: We conducted a systematic review following the PRISMA guidelines. Electronic searches were conducted in September 2025 using MEDLINE®, PsycINFO, and EMBASE, as it was forward citation tracking via Scopus. RESULTS: Twenty-eight studies met inclusion criteria from an initial pool of 157 identified papers. Evidence consistently indicated significant associations between traumatic life experiences - particularly emotional neglect, physical abuse, and sexual trauma - and the onset and exacerbation of OCD symptoms. Specific types of trauma predicted OCD symptom profiles. Interpersonal traumas were predominantly associated with obsessions of unacceptable thoughts and responsibility for harm, while non-interpersonal traumas were more strongly linked to contamination themes. Trauma exposure also increased OCD severity and psychiatric comorbidity risk. CONCLUSIONS: Trauma seems to significantly amplify OCD symptom severity and influence symptom presentation. Trauma-informed clinical assessment and tailored interventions should be integral to OCD treatment.