Clinical and Epidemiological Studies

Epidemiological and clinical studies support a strong association between depression and GAD, OCD, and PTSD. The National Comorbidity Survey (NCS) demonstrated that 58% of primarily depressed patients also experienced an anxiety disorder, estimating the rate of comorbidity between depression and GAD to be 17.2% (Kessler et al., 1996). The NCS found that of those individuals with a primary diagnosis of current GAD, 39% had current major depression and 22% had current dysthymia (Judd et al., 1998). Studies also suggest comorbidity rates of 21-54% between depression and OCD (Abramowitz, 2004). Epidemiological and clinical studies also indicate that up to 56% of individuals have concurrent PTSD and depression, and that as many as 95% of individuals with PTSD have a lifetime history of major depression (Bleich, Koslowsky, Dolev, & Lerer, 1997).

In clinical studies, an association between depression and anxiety is also supported. Brown and Barlow (1992), for example, found that 55% of patients with an anxiety or mood disorder met the diagnostic criteria for an additional concurrent anxiety or depressive disorder. The rate was even higher when lifetime diagnoses were examined. Major depressive disorder (MDD), dysthymia, PTSD, and GAD were the most highly comorbid disorders.

Research suggests that an anxiety disorder is more likely to precede a mood disorder than the reverse (Mineka, Watson, & Clarke, 1998). The risk ofMDD within a given year increases significantly during the year after first onset of an anxiety disorder, with an odds ratio (OR) of 62.0 for GAD (Kessler et al., 1996). Similarly, In the case of PTSD, studies suggest that in the majority of cases depression is secondary to the PTSD (Shalev et al., 1998). Retrospective data from the NCS, for example, suggest that 78.4% of individuals with comorbid depression and PTSD experienced clinically significant depression after the onset of the PTSD (Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995). However, a 1-year prospective study showed that depression and PTSD can also occur simultaneously upon exposure to trauma (Shalev et al., 1998). Comorbid depression was present in 44.5% of patients with PTSD at 1 month, and 43.2% of patients at 4 months following the traumatic event.

Comorbidity is also associated with greater severity of symptomatology and functional impairment (Brown, Schulberg, Madonia, Shear, & Houck, 1996). Patients with depression and anxiety, for instance, frequently respond less well to treatment (Nutt, 2000) and accrue more demands on the health care system than do individuals with either disorder alone (Tylee, 2000). Compared to patients with depression alone, individuals with anxious depression also tend to have more severe symptoms and pose a greater risk for suicide (Stein, 2001). Shalev et al. (1998) also found that, relative to individuals with PTSD, those with comorbid depression had more severe symptomatology and lower levels of functioning.

How To Win Your War Against Anxiety Disorders

How To Win Your War Against Anxiety Disorders

Tips And Tricks For Relieving Anxiety... Fast Everyone feels anxious sometimes. Whether work is getting to us or we're simply having hard time managing all that we have to do, we can feel overwhelmed and worried that we might not be able to manage it all. When these feelings hit, we don't have to suffer. By taking some simple steps, you can begin to create a calmer attitude, one that not only helps you feel better, but one that allows you the chance to make better decisions about what you need to do next.

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