Generalized Anxiety Disorder
Generalized anxiety disorder, or GAD, is characterized by excessive worry and anxiety according to the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders. While most people experience some worry or anxiety in a lifetime, someone suffering from GAD feels worry and anxiety more often than not. They have trouble controlling these feelings and also feel restless or on edge, are easily tired and have trouble concentrating. In GAD the person is also irritable, experiences muscle tension or has sleep pattern disruptions.
The symptoms of GAD and the anxiety and worry extend into multiple aspects of the individual’s life. GAD is differentiated from other anxiety disorders by its lengthy duration, as symptoms of GAD must have been present for at least six months before a diagnosis of the disorder can be made.
Post Traumatic Stress Disorder
According to the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders, post traumatic stress disorder, or PTSD, is an anxiety disorder that sometimes occurs after an individual witnesses a traumatic event that involves actual or threatened death or serious injury to self or others.
In response to the event, the individual feels scared, hopeless or horrified and re-experiences the trauma for at least one month following the trauma. Individuals suffering from PTSD may re-experience the trauma through images, thoughts or feelings, dreams, flashbacks including illusions or hallucinations, or psychological or physiological distress in response to cues that symbolize the traumatic event.
Those suffering from PTSD avoid stimuli associated with the trauma by trying not to think, feel or talk about it. They avoid places, activities and people that remind them of the trauma and cannot recall specifics about it. They lose interest in things they once cared about and often remain detached from others.
Emotions may appear blunted and the person envisions a short future where they don’t believe they will have a career, marriage, children or a normal lifespan. Lastly, PTSD manifests with sleep pattern disturbances, irritability or angry outbursts, difficulty concentrating, hyper-vigilance and easy startled responses.
Comorbidity of GAD and PTSD
Larry Beall, Ph.D. reports on the TraumaAwareness.org website that GAD sometimes occurs together with PTSD. PTSD vs Generalized Anxiety Disorder is explained in a study by Brown et al. published in the Journal of Abnormal Psychology. The study notes the prevalence of comorbidity of GAD and PTSD as possible proof of a lack of diagnostic reliability of GAD.
Another possibility is that GAD is defined with such broad definitional criteria that it naturally overlaps into more specific disorders. For example, GAD is characterized by significant anxiety and worry that may surface when an individual suffers from PTSD as well. In both illnesses, individuals may avoid places, activities and people in response to anxiety and worry. To further explain PTSD vs Generalized Anxiety Disorder, Brown et al. puts forth another possible theory, claiming that comorbidity may arise due to features of one disorder serving as a risk factor for the development of the other. For example, an individual who suffers from GAD and then experiences a traumatic event may be more likely to experience symptoms of PTSD due to a pre-existing tendency towards excessive worry and anxiety that is magnified by witnessing a traumatic event.
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (4th ed.). Washington, DC.
Brown, Timothy A.,Campbell, Laura A., Lehman, Cassandra L., Grisham, Jessica R., Mancill, Richard B. "Current and Lifetime Comorbidity of the DSM-IV Anxiety and Mood Disorders in a Large Clinical Sample." Journal of Abnormal Psychology 110(2001): 585-599