A new study indicates that 13.5 per cent of Canadian Forces personnel who served in Afghanistan have come home with mental disorders.

The article was published today in the Canadian Medical Association Journal. The authors, David Boulos and Mark A. Zamorski, work in the Directorate of Mental Health, Canadian Forces Health Services Group Headquarters in Ottawa.

For the report, they chose a random sample of 2,014 personnel from 30,513 who had been deployed in Afghanistan between the start of hostilities in 2001 and January 1, 2009. The report abstract says: "The primary outcome was a mental disorder perceived by a Canadian Force clinician to be related to the Afghanistan deployment." The abstract presents their results:

Over a median follow-up of 1364 days, 13.5% (95% confidence interval [CI] 12.1%-14.8%) of the study population had a mental disorder that was attributed to the Afghanistan deployment. Posttraumatic stress disorder was the most common diagnosis (in 8.0%, 95% CI 7.0%-9.0%, of personnel).

Deployment to higher-threat locations, service in the Canadian Army and lower rank were independent risk factors associated with an Afghanistan-related diagnosis (e.g., hazard ratio for deployment to Kandahar Province 5.6, 95% CI 2.6-12.5, relative to deployment to the United Arab Emirates). In contrast, sex, Reserve Forces status, multiple deployments and deployment length were not independent risk factors.

The disorders had to meet the criteria set out in the Diagnostic and Statistical Manual of Mental Disorders, fourth edition. The authors go on to say:

The most common Afghanistan-related disorder was PTSD (8.0%), followed by depressive disorders (6.3%, 60.3% [1158/1919] of which were comorbid with PTSD). An additional 5.5% (95% CI 4.5%–6.6%) of the cohort had a mental disorder judged to be unrelated to their Afghanistan deployment; this group included the 1.2% (95% CI 0.7%–1.7%) of the cohort who had a mental disorder related to other Canadian Forces operations.

The authors conclude that "Determining long-term outcomes is an important next step."

A search of the National Defence and Canadian Forces website turned up 294 files dealing with post-traumatic stress disorder and 905 files dealing with depression.

The Tyee has reported on the issue of mental health of returning Afghanistan veterans here, here, and here.

Crawford Kilian is a contributing editor of The Tyee.