Survey
Data were from a cross-sectional population-based survey of Canadian Forces personnel collected between May and December 2002 (
13 ). The CCHS-CFS 1.2 employed a multistage sampling framework to ensure the representativeness of the sample in relation to the Canadian military (details of the sampling frame of the survey are available on request) (
13 ). The sample consisted of 5,155 regular force members (response rate 80%) and 3,286 reserve force members (response rate 84%). Reserve members were included in the target population if they had been active in the Canadian Forces in the six months before data collection.
To preserve anonymity, no information was available about the specific deployment location of these soldiers. However, on the basis of the age range of the sample, it is likely that the soldiers were involved in several missions, including those to Iraq (the first Gulf War), Rwanda, Somalia, and the former Yugoslavia.
Measures
Perceived need for mental health care. The PNCQ, developed by Meadows and colleagues (
4,
17 ), was included in the CCHS-CFS 1.2. Data on the reliability and validity of the PNCQ have been previously reported. The PNCQ assesses whether in the past year a respondent perceived a need or received help for problems with emotions, mental health, or use of alcohol or drugs. Five types of need are assessed: information about mental health problems and available treatments and services, medication, therapy or counseling, social intervention (for financial or housing problems), and skills training (for employment status, work situation, or personal relationships).
Sociodemographic factors. Sociodemographic factors assessed included sex, age, marital status, income, education, military rank (junior, senior, or officer), type of service (regular or reserve), and type of personnel (land, air, sea, or communications).
Deployment variables. Deployment was defined as "deployed in support of a mission, such as a NATO mission or a UN tour. These deployments must be of at least 3 months duration." Number of deployments was assessed: "How many deployments lasting 3 months or more have you had in your career? Include deployments as a regular or reserve Canadian Forces member." Participants could endorse zero, one, two, three, four, or five or more deployments. Any individual who indicated one or more deployments was classified as having been deployed. Another question with a dichotomous response assessed the tempo of deployment: "During your career, was there ever a period of less than 12 months between the time you completed one deployment and the time you started another?" The notice given to the participant before deployment was also assessed: "Thinking about your most recent deployment, how much notice did you receive prior to the deployment?" Participants could choose less than one month, one to three months, four to six months, or more than six months. Family members' concerns about deployment were assessed: "Did your immediate family express any concerns regarding this deployment?" A single question examined whether the participant had ever been deployed as an augmentee, defined as being "deployed with a unit other than [his or her] home unit." Finally, participants reported the length of time away from home because of work-related activities (zero to five months, six to 12 months, and more than 12 months).
Separate questions were asked about combat exposure, peacekeeping operations, and witnessing atrocities. In conjunction with the deployment variable, we created a three-level categorical variable to account for different types of deployment-related experiences (not deployed, deployed with no exposure to combat or atrocities, and deployed with exposure to combat or atrocities). Because our previous work emphasized the poor mental health outcomes related to combat and witnessing atrocities (
13 ), these events were grouped together and separate from peacekeeping operations.
Mental disorders. The content of the survey was partly based on a selection of mental disorders from the World Mental Health Survey initiative (WMH 2000) (
18,
19,
20 ). The World Health Organization (WHO) Composite International Diagnostic Interview (CIDI) version 2.1 was used to generate diagnoses according to both
ICD-10 and
DSM-IV definitions and criteria. The CIDI is a fully structured instrument for use by lay interviewers who do not have clinical experience; it has high levels of reliability and consistency with the clinician-based diagnoses of
DSM disorders assessed in this survey. The interviewers were trained according to WMH 2000 standards (
20 ). The CCHS-CFS 1.2 methodology has been described elsewhere (
21 ). Past-year prevalence rates of five
DSM-IV mental disorders were assessed: major depressive disorder, panic disorder, social phobia, generalized anxiety disorder, and posttraumatic stress disorder (PTSD). The CIDI Short Form was used to assess alcohol dependence based on
DSM-IV criteria; three symptoms or more indicated alcohol dependence (
22 ).
Long-term restriction of activities. Participants were asked if a long-term physical health condition, mental health condition, or health problem had reduced the amount or kind of activity "at home," "at school," "at work," or "in other activities, for example, transportation or leisure." For each of the areas of reduced functioning, the respondent had the choice of sometimes, often, or never. Because of the skewed distribution of this variable, it was dichotomized. Respondents endorsing never for all areas of functioning were categorized as "not restricted," and the others were categorized as "restricted."
Past-year suicidal ideation. Participants were asked whether they had seriously thought about committing suicide in the past 12 months.