Bayesian Analysis of Current and Lifetime Comorbidity Rates of Mood and Anxiety Disorders In Individuals with Posttraumatic Stress Disorder

Abstract

Although posttraumatic stress disorder (PTSD) is no longer considered an anxiety disorder in DSM-5, previous research has indicated high rates of comorbid anxiety and mood disorders in individuals with PTSD. The goal of the present study was to build upon previous examinations of diagnostic comorbidity by using Bayesian methods of estimating current and lifetime comorbidity rates to determine more precise estimates of the proportion of individuals in a clinical sample with PTSD that also meet criteria for various emotional disorders. Two hundred and fifty three individuals with a current or lifetime diagnosis of PTSD underwent a comprehensive assessment of current and lifetime emotional disorders. Bayesian statistical techniques were then used to calculate credibility intervals for the current and lifetime comorbidity rates of emotional disorders. The Bayesian analyses used informative priors based on previous comorbidity findings. The median number of current emotional disorders was two and the median number of lifetime comorbid emotional disorders was three. Credibility intervals indicated that social phobia and major depressive disorder were the most common current and lifetime comorbid emotional disorders. The proportion of individuals with lifetime comorbidity rates were very high for both any lifetime anxiety disorder (.91, 95% CI .88: .94) and any lifetime depressive disorder (.90, 95% CI .86: .93). Together these results indicate that despite the separation from the anxiety disorders in DSM-5, the vast majority of individuals with PTSD will present with one or more emotional disorders. Implications for the assessment and treatment of PTSD are discussed.

Keywords: Assessment/Diagnosis; Bayesian analysis; PTSD; anxiety; depression.