Multimorbidity among Veterans Diagnosed with PTSD in the Veterans Health Administration Nationally.

Over 30% of veterans treated for psychiatric disorders in the Veterans Health Administration (VHA) are diagnosed with Post-Traumatic Stress Disorder (PTSD), with most receiving treatment for war-zone stress they experienced decades previously. We examined psychiatric multimorbidity among these patients and consider its implications for treatment and research. Using national VHA data from Fiscal Year 2012 on all veterans diagnosed with PTSD, we compared those with PTSD only to those with one, two, and three or more concurrent (non-substance use) psychiatric disorders. Comparisons of these four groups on sociodemographic characteristics, medical and substance use co-morbidities, health service use, and psychotropic prescription fills were conducted using bi-variate and ordinal logistic regression methods. Of 638,451 veterans diagnosed with PTSD in FY2012, only 29.8% had PTSD alone; 36.7% had one concurrent psychiatric diagnosis, 21.3% had two, and 12.2% had three or more. Anxiety disorder and major depressive disorder were the most common concurrent diagnoses. Veterans with higher levels of multimorbidity were younger, had greater likelihood of recent homelessness, substance use disorder, and diverse medical diagnoses, along with increased mental health and medical service use and greater psychotropic medication use. Psychiatric multimorbidity is highly prevalent among VHA patients diagnosed with PTSD, and may represent an underappreciated and poorly understood clinical complication that poses unique challenges to effective treatment. Clinical attention and both epidemiological and interventional research on multimorbidity in PTSD patients are needed in order to better understand and treat this common but understudied phenomenon.