In 1994, the Defense Women’s Health Research Program was initiated as a special congressional appropriation to provide an opportunity to support military operational medicine research focused on several gender- and task-specific health related problems that could adversely affect performance. Funds were distributed to DoD research projects and complementary external research, as well as to develop an innovative knowledge management system for the Defense Women’s Health Information Clearinghouse. The program, however, ended without development of an enduring infrastructure for women’s health research. Therefore, there is limited research specific to female service members’ health, particularly psychological or mental health issues for female service members. Difficulties in obtaining large samples of female service members for specific studies and a lack of standard constructs have further restricted this research.
Overall, while evidence suggests a higher prevalence rate for females for some mental health disorders;  there are no conclusive findings regarding potential gender differences in the prevalence and impact of most mental health disorders, including anxiety disorders, serious mental illness, eating disorders and depression.
Posttraumatic Stress Disorder
With regards to posttraumatic stress disorder (PTSD), some studies have found higher rates of PTSD among female service members as compared to males, while others have found no differences between genders. For instance, the Mental Health Advisory Team-II, which looked at mental health issues in service members related to Operation Iraqi Freedom found essentially equal rates of PTSD in females (12 percent) and males (13 percent). Research reflects that when the type of trauma exposure is considered, findings may indicate that type (e.g., combat trauma, sexual trauma, etc.) and severity of trauma exposure may be more predictive of PTSD than gender. At least one study has found males and females to be equally resilient to the effects of combat exposure. While some research suggests females are slightly more likely to receive a diagnosis of PTSD than males, there are other conflicting findings.
Substance Use Disorders
Research on the prevalence of substance use disorders in female service members has primarily focused on alcohol and tobacco use. These study results indicate there are higher rates of alcohol use among males versus females, consistent with patterns observed in civilian samples. 
Few empirical studies have specifically examined issues related to gender and suicidality, although these rates are closely monitored by national surveillance mechanisms. Consistent with general population norms, data indicate the risk for completed suicide is lower for female service members, relative to their male counterparts. The specific role of gender along with other individual and contextual factors in suicide risk is complex and many questions remain.
Several studies have explored the interaction of intimate and family relationships with mental health conditions in service members, but these studies have not specifically examined treatment options or outcomes. Little is currently known about potential gender differences in the experience of post-deployment family problems. There have been few studies related to mental health and pregnancy/postpartum issues among female service members, though early evidence suggests higher rates of postpartum depression symptoms among female service members relative to population norms. Research on mental health services utilization found that females are more likely than males to self-refer and use mental health services. However, there is limited research on female service members’ mental health treatment preferences or satisfaction with care.
The current body of evidence on female service members’ mental health issues is limited, though it continues to evolve. There are many areas for further research to examine gender differences in prospective study designs with representative samples of service members. Additional research on the prevalence and impact of most mental health conditions, to include serious mental illness, eating disorders and depressive disorders is necessary. Following the work of a joint DoD and VA work group for Integrated Mental Health Strategy (IMHS) Strategic Action #28 Explore Gender Differences in Delivery and Effectiveness of Mental Health Services, several specific areas for future research have been identified, to include the need to examine:
- The relationship between gender and resilience to different types of trauma exposure
- The relationship between gender and prevalence of substance use disorders other than alcohol and tobacco
- Issues related to gender and suicide
- Treatment options and outcomes for mental health issues related to intimate partner violence and family relationships
- Gender differences in post-deployment family problems
- Mental health and pregnancy/postpartum issues
- Factors associated with gender disparities in mental health service utilization, including the availability and female service members’ awareness of gender-sensitive and gender-specific treatment options
- Gender differences in mental health treatment preferences, treatment efficacy and outcomes, and factors associated with patient satisfaction
In addition to future research in these identified areas within women’s mental health, the IMHS SA #28 Work Group recommended that a DoD Women’s Mental Health Work Group be established, to monitor progress towards addressing DoD gaps and recommendations, and to communicate progress towards addressing gaps and updated recommendations to DoD leadership, key stakeholders and points of contact.