Incidence of mental disorders and its predictors among air force personnel exposed to counter-insurgency operations in a West African country: a 6-month follow-up study.

Background: Despite robust reports in the literature concerning the effect of exposure to combat on mental health, there is a paucity of studies in the Nigerian Air Force (NAF) using a longitudinal design. This study was designed to determine the incidence of mental disorders among a cohort of NAF personnel exposed to combat and highlight its association with psychosocio-religious variables.

Methods: It was a follow-up study using a total population sampling in which all the 290 deployed personnel participated. Data was collected at two intervals: Baseline and 6 months after with sociodemographic questionnaire, Brief Coping Orientation to Problems Experienced Inventory, the Brief Religious Coping, the Oslo Social Support Scale and the Big Five Inventory, General Health Questionnaire (GHQ-12) and the Mini-International Neuropsychiatric Interview (MINI-Plus). A two-staged process involving screening with the GHQ and a further diagnostic interview using MINI-Plus for participants with a GHQ score of 2 and above.

Results: The incidence of any mental disorder was 243.1 per 1000 person-years. The top three priority conditions were: Substance use disorder (94.1 per 1000 person-years), major depressive disorder (43.8 per 1000 person-years) and post-traumatic stress disorder (PTSD) (41.6 per 1000 person-years). Being deployed in early adulthood was a risk factor for developing a mental illness (adjusted OR (AOR), (95% CI): 2.89, (1.28, 6.50), p=0.01) while longer duration in the military service was a protective factor (AOR, (95% CI): 0.95, (0.91, 0.99), p=0.03). Social support, personality traits, religious coping and other coping strategies did not significantly predict mental disorders in this population (p>0.05).

Conclusion: The incidence of any mental disorder among NAF personnel exposed to combat was huge. The three top priority conditions were substance use disorder, major depressive disorder and PTSD. These findings are useful in identifying priority conditions for interventions in the NAF population.