OBJECTIVE: To review studies that have evaluated the comorbidity between posttraumatic stress disorder and mood disorders, as well as between posttraumatic stress disorder and other anxiety disorders. METHOD: We searched Medline for studies, published in English through April, 2009, using the following keywords: 'posttraumatic stress disorder', 'PTSD', 'mood disorder', 'major depressive disorder', 'major depression', 'bipolar disorder', 'dysthymia', 'anxiety disorder', 'generalized anxiety disorder', 'agoraphobia', 'obsessive-compulsive disorder', 'panic disorder', 'social phobia', and 'comorbidity'. RESULTS: Major depression is one of the most frequent comorbid conditions in posttraumatic stress disorder individuals, but individuals with posttraumatic stress disorder are also more likely to present with bipolar disorder, other anxiety disorders and suicidal behaviors. These comorbid conditions are associated with greater clinical severity, functional impairment, and impaired quality of life in already compromised individuals with posttraumatic stress disorder. Depression symptoms also mediate the association between posttraumatic stress disorder and severity of pain among patients with chronic pain. CONCLUSION: Available studies suggest that individuals with posttraumatic stress disorder are at increased risk of developing affective disorders compared with trauma-exposed individuals who do not develop posttraumatic stress disorder. Conversely, pre-existing affective disorders increase a person's vulnerability to the posttraumatic stress disorder--inducing effects of traumatic events. Also, common genetic vulnerabilities can help to explain these comorbidity patterns. However, because the studies addressing this issue are few in number, heterogeneous and based on a limited sample, more studies are needed in order to adequately evaluate these comorbidities, as well as their clinical and therapeutic implications.
OBJECTIVE: To review studies that have evaluated the comorbidity between posttraumatic stress disorder and mood disorders, as well as between posttraumatic stress disorder and other anxiety disorders. METHOD: We searched Medline for studies, published in English through April, 2009, using the following keywords: 'posttraumatic stress disorder', 'PTSD', 'mood disorder', 'major depressive disorder', 'major depression', 'bipolar disorder', 'dysthymia', 'anxiety disorder', 'generalized anxiety disorder', 'agoraphobia', 'obsessive-compulsive disorder', 'panic disorder', 'social phobia', and 'comorbidity'. RESULTS: Major depression is one of the most frequent comorbid conditions in posttraumatic stress disorder individuals, but individuals with posttraumatic stress disorder are also more likely to present with bipolar disorder, other anxiety disorders and suicidal behaviors. These comorbid conditions are associated with greater clinical severity, functional impairment, and impaired quality of life in already compromised individuals with posttraumatic stress disorder. Depression symptoms also mediate the association between posttraumatic stress disorder and severity of pain among patients with chronic pain. CONCLUSION: Available studies suggest that individuals with posttraumatic stress disorder are at increased risk of developing affective disorders compared with trauma-exposed individuals who do not develop posttraumatic stress disorder. Conversely, pre-existing affective disorders increase a person's vulnerability to the posttraumatic stress disorder--inducing effects of traumatic events. Also, common genetic vulnerabilities can help to explain these comorbidity patterns. However, because the studies addressing this issue are few in number, heterogeneous and based on a limited sample, more studies are needed in order to adequately evaluate these comorbidities, as well as their clinical and therapeutic implications.