This project proposes two related studies. The first project is a randomized clinical trial of 120 veterans identified with high-risk suicidal behavior comparing the efficacy of DBT vs. treatment as usual (TAU) on suicidal behavior as a primary outcome measure. A second aim of the present project is to examine group differences between 200 300 veterans at high risk for suicide and 200 veterans at low risk in a variety of symptom domains. The goal of this will be to identify symptoms associated with suicidal behavior that can be used as secondary and exploratory outcome measures for DBT. The investigators will assess symptom domains including mood and substance use that have been associated with suicidal behavior by previous research and validate those in our veteran population by comparing symptoms in low vs. high risk veterans recently discharged from the James J Peters VAMC (JJPVA) psychiatric inpatient unit. In addition, the investigators will explore indices of interpersonal function and measure features that have some evidence of offering protection from suicide, which could be viewed as resilience factors. A particular emphasis of the present project is to characterize the nature of the interpersonal dysfunction in high risk individuals, as there exists very good evidence that social isolation, or a lack of a sense of "belonging" puts people at particularly high risk for suicide, in particular in a military sample. The investigators intend to assess the impact of DBT vs. TAU on these symptom domains in addition to their impact on suicidal behavior.

The subject population for both projects will be veterans identified on a "high risk" suicide list at the James J. Peters VAMC; veterans are so identified by the suicide coordinator because of a recent inpatient hospitalization involving high-risk suicidal behavior. Priority will be given to OEF/OIF veterans. In order to identify symptoms associated with high risk suicidal behavior, the investigators will examine symptoms domains in our high risk subjects and contrast them with a comparison group of veterans recently discharged from the psychiatric inpatient service or treated in the outpatient mental health department at the James J Peters VA Medical Center with no history of high-risk suicidal behaviors (low risk veterans). Groups will be matched with respect to age and gender. For this project, the investigators will include veterans with a variety of diagnoses, including post-traumatic stress disorder (PTSD), substance abuse, affective disorders, personality disorders, and anxiety disorders. The investigators will exclude subjects with current psychosis or cognitive impairment as these symptoms would prevent appropriate engagement in DBT. Patients from the high-risk suicide list will be eligible to participate in a six month DBT treatment study and will be randomized to full DBT vs. TAU. Both groups will have psychopharmacological management by their outpatient psychiatrist and be able to participate in standard ancillary outpatient clinical offerings (e.g. AA, sleep group). Both treatment groups will be assessed at baseline, at the 6 month treatment completion mark, as well as follow-up time points including one year and eighteen months after enrollment.