Experiencing traumatic life events is associated with an increased risk of common mental disorders (CMDs), but studies investigating this association within Indigenous populations are limited.

The aim of this study was to investigate associations between trauma and CMDs after controlling for other exposures.

Trauma exposures and CMD diagnoses were determined in a broadly representative sample of 544 Indigenous Australians, using a diagnostic clinical interview. Associations were determined by multivariate logistic regression.

Trauma exposure independently predicted CMDs. After adjustment for potential confounders, trauma exposure was associated with a 4.01-fold increased risk of a diagnosis of a CMD in the past 12 months. The increased risks were 4.38-, 2.65- and 2.78-fold of having an anxiety disorder, mood disorder or a substance use disorder, respectively. Trauma exposure and comorbid post-traumatic stress disorder was associated with a 4.53-fold increased risk of a diagnosis of a mood disorder, 2.47-fold increased risk of a diagnosis of a substance use disorder, and 3.58-fold increased risk of any diagnosis of a CMD, in the past 12 months. Experiencing both sexual and physical violence was associated with a 4.98-fold increased risk of a diagnosis of an anxiety disorder in the past 12 months.

Indigenous Australians experience significantly increased exposure to potentially harmful trauma compared with non-Indigenous Australians. Preventing and healing trauma exposure is paramount to reduce the high burden of CMDs in this population.