نشخوار فکری به عنوان یک عامل فراتشخیصی در افسردگی و اضطراب

The high rate of comorbidity among mental disorders has driven a search for factors associated with the development of multiple types of psychopathology, referred to as transdiagnostic factors. Rumination is involved in the etiology and maintenance of major depression, and recent evidence implicates rumination in the development of anxiety. The extent to which rumination is a transdiagnostic factor that accounts for the co-occurrence of symptoms of depression and anxiety, however, has not previously been examined. We investigated whether rumination explained the concurrent and prospective associations between symptoms of depression and anxiety in two longitudinal studies: one of adolescents (N = 1065) and one of adults (N = 1317). Rumination was a full mediator of the concurrent association between symptoms of depression and anxiety in adolescents (z = 6.7, p < .001) and was a partial mediator of this association in adults (z = 5.6, p < .001). In prospective analyses in the adolescent sample, baseline depressive symptoms predicted increases in anxiety, and rumination fully mediated this association (z = 5.26, p < .001). In adults, baseline depression predicted increases in anxiety and baseline anxiety predicted increases in depression; rumination fully mediated both of these associations (z = 2.35, p = .019 and z = 5.10, p < .001, respectively). These findings highlight the importance of targeting rumination in transdiagnostic treatment approaches for emotional disorders.

The high degree of comorbidity between certain mental disorders, particularly depression and anxiety disorders (Brown, Cambell, Lehman, Grisham, & Mancill, 2001), has led to a search for mechanisms responsible for this comorbidity, often referred to as transdiagnostic factors (Ehring and Watkins, 2008, Harvey et al., 2004, Mansell et al., 2008 and Norton et al., 2008). Many transdiagnostic factors have been proposed to link depression and anxiety, including elements of affect, attention, memory, reasoning, thought, and behavior (Ehring and Watkins, 2008, Harvey et al., 2004, Mansell et al., 2008, Moses and Barlow, 2006, Norton et al., 2008 and Watson and Clark, 1984). Recently, repetitive negative thinking has been suggested to be an important transdiagnostic factor (Ehring and Watkins, 2008, Harvey et al., 2004, Nolen-Hoeksema et al., 2008 and Watkins, 2008). As Ehring and Watkins (2008) note, several disorder-specific definitions of maladaptive repetitive negative thinking exist, but all describe this process as (a) repetitive thoughts that are (b) passive and/or relatively uncontrolled, and (c) focused on negative content. The specific type of repetitive negative thinking most frequently examined across a range of disorders, especially depression and anxiety disorders, is rumination. Nolen-Hoeksema defines rumination as a pattern of responding to distress in which an individual passively and perseveratively thinks about his or her upsetting symptoms and the causes and consequences of those symptoms, while failing to initiate the active problem solving that might alter the cause of that distress ( Nolen-Hoeksema and Morrow, 1991). Experimental studies show that inducing this type of rumination in the context of distress leads to increases in both depressed and anxious mood ( Blagden and Craske, 1996 and McLaughlin et al., 2007). Studies using questionnaire measures of rumination such as the Ruminative Responses Scale ( Treynor, Gonzalez, & Nolen-Hoeksema, 2003) show that rumination predicts the later development of depressive symptoms ( Broderick and Korteland, 2004, Nolen-Hoeksema et al., 1993, Nolen-Hoeksema et al., 1994, Nolen-Hoeksema et al., 2007 and Schwartz and Koenig, 1996) as well as the future onset, number and duration of major depressive episodes ( Just and Alloy, 1997, Nolen-Hoeksema, 2000, Nolen-Hoeksema et al., 2007 and Robinson and Alloy, 2008). The tendency to ruminate also has been associated with self-reported symptoms of generalized anxiety ( Fresco et al., 2002 and Harrington and Blankenship, 2002), post-traumatic stress ( Clohessy and Ehlers, 1999, Mayou et al., 2002 and Nolen-Hoeksema and Morrow, 1991), and social anxiety ( Mellings & Alden, 2000). Rumination may lead to both anxiety and depression through a variety of mechanisms. Experimental induction of rumination in distressed individuals leads to more maladaptive, negative thinking (Lyubomirsky, Caldwell, & Nolen-Hoeksema, 1998), less effective generation of solutions to problems (Donaldson and Lam, 2004, Lyubomirsky and Nolen-Hoeksema, 1995, Watkins and Baracaia, 2002 and Watkins and Moulds, 2005), uncertainty and immobilization in the implementation of solutions to problems (Lyubomirsky et al., 2006 and Ward et al., 2003), and less willingness to engage in distracting, mood-lifting activities (Lyubomirsky & Nolen-Hoeksema, 1993). Survey and observational studies also show that people who ruminate experience less social support and more social friction (Nolen-Hoeksema & Davis, 1999), and are viewed less favorably by others (Schwartz & McCombs, 1995). Although multiple studies have examined the relationships between rumination and symptoms of anxiety and depression in the same sample (Fresco et al., 2002, McLaughlin et al., 2007, Nolen-Hoeksema, 2000 and Segerstrom et al., 2000), none of these studies has examined whether rumination accounts for the relationship between anxiety and depression in a sample. If rumination is indeed a transdiagnostic factor that leads to both depression and anxiety, we would expect that rumination is responsible, at least in part, for the comorbidity between symptoms of depression and anxiety and would account for their co-occurrence to a significant degree. In the study reported here, we tested the prediction that rumination would statistically account for the relationship between symptoms of anxiety and depression both cross-sectionally and longitudinally. We tested this prediction in two samples, one comprised of early adolescents aged 11–14 years and the other comprised of adults ranging in age from 25 to 75 years. If rumination is truly a transdiagnostic factor in the co-occurrence of anxiety and depressive symptomatology, we expect to find evidence for its role in the overlap of such symptoms at a single point in time, across time, and in individuals at different points in the life course.