OBJECTIVE: This prospective study aimed to investigate whether prior internalizing disorders (PIDs) moderate the relationship between stress exposure (SE) and the onset of alcohol use disorders (AUDs) and nicotine dependence (ND) in deployed military personnel.

METHODS: 358 male soldiers were examined directly before and 12months after return from deployment using standardized interviews. Combat experiences, concerns about family disruptions, and difficult living and working environment were assessed as different aspects of SE. PID diagnoses (mood disorders (PMDs), anxiety disorders (PADs)) and substance use disorders were defined according to the DSM-IV-TR.

RESULTS: PMDs were related to a stronger association between concerns about family disruptions and the risk of AUD onset (OR=7.7, 95% CI 1.8-32.8, p=0.006). The number of PID diagnoses (OR per diagnosis: 1.7, 95% CI 1.0-2.8, p=0.036) and PADs (OR: 2.6, 95% CI 1.1-6.3, p=0.038) were further related to a stronger association between difficult living and working environment and the risk of AUD onset. With regard to ND, PMDs were related to a weaker association between difficult living and working environment and the risk of ND onset (OR=0.4, 95% CI 0.2-0.8, p=0.013).

CONCLUSIONS: PIDs might be related to an increased risk for the onset of AUDs but not ND following SE. This effect is probably restricted to specific constellations of PADs, PMDs, comorbid PIDs and specific aspects of SE. These critical constellations of PIDs and SE might be a promising target for future research and could contribute to the development of preventive measures to reduce the risk of AUDs following SE.