Cohort profile: the Ohio Army National Guard Mental Health Initiative (OHARNG-MHI)

Rates of mental disorders in the United States military have increased in recent years. National Guard members may be particularly at risk for mental disorders, given their dual role as citizen-soldiers and their increased involvement in combat deployments during recent conflicts. The Ohio Army National Guard Mental Health Initiative (OHARNG-MHI) was launched to assess the prevalence, incidence, and potential causes and consequences of mental disorders in this unique population. OHARNG-MHI is a decade-long dynamic cohort study that followed over 3,000 National Guard members yearly through structured telephone interviews. Findings thus far have applied a pre-, peri-, post-deployment framework, identifying factors throughout the life course associated with mental disorders, including childhood events and more recent events, both during and outside of deployment. An estimated 61% of participants had at least one mental disorder in their lifetime, the majority of which initiated prior to military service. Psychiatric comorbidity was common, as were alcohol use and stressful events. Latent class growth analyses revealed four distinct trajectory paths of both posttraumatic stress and depression symptoms across four years. Only 37% of soldiers with probable past-year mental disorders accessed mental health services in the subsequent year, with substance use disorders least likely to be treated. Strengths of this study include a large number of follow-up interviews, detailed data on both military and non-military experiences, and a clinical assessment subsample that assessed the validity of the telephone screening instruments. Findings, methods, and procedures of the study are discussed, and collaborations are welcome.