PTSD Symptoms and Childhood Maltreatment Influence Alcohol and Drug Addiction Severity

Background Trauma and post-traumatic stress disorder (PTSD) are critical factors influencing the onset, presentation, and prognosis of substance use disorders (SUDs). This study aimed to determine the prevalence of trauma and lifetime PTSD in a treatment-seeking SUD population in Hong Kong, and to examine cross-sectional associations between PTSD symptom clusters, childhood trauma subtypes, and alcohol and drug addiction severity. Methods In this cross-sectional study, 160 Chinese adults from inpatient and outpatient substance misuse units were assessed using the Clinician-Administered PTSD Scale (CAPS), Addiction Severity Index (ASI), Life Event Checklist (LEC), and the Childhood Trauma Questionnaire (CTQ). Two-stage multivariable linear regression models identified factors independently associated with addiction outcomes. Results Lifetime trauma exposure was reported by 80.0% of the sample, and 39.4% met criteria for lifetime PTSD. For alcohol addiction severity (R 2 adj = .52, p < .001), lifetime PTSD, higher CAPS re-experiencing, and higher CAPS avoidance/numbing severity were independent positive correlates. For drug addiction severity ( R 2 adj = .65, p < .001), lifetime PTSD and higher CAPS avoidance/numbing severity, but not re-experiencing, were independent positive correlates. Continuous subscale analysis revealed that childhood sexual abuse and emotional neglect independently predicted higher alcohol and drug severity ( p ≤ .011). Conclusions Trauma pathology and childhood maltreatment are common among individuals seeking treatment for SUD in Hong Kong. The unique association of re-experiencing symptoms with alcohol severity, alongside the association of avoidance/numbing with both alcohol and drug addiction, highlights a distinct symptom-substance co-occurrence profile. These findings underscore the need for trauma-informed frameworks and integrated PTSD treatment within addiction services.