From a conceptual and research design perspective, a putative vulnerability factor for a disorder must be demonstrated to meet two criteria (Alloy, Abramson, Raniere, & Dyller, 1999; Ingram, Miranda, & Segal, 1998): It must temporally precede the initial onset of the disorder or, in the case of a vulnerability factor for the course of a disorder, precede episodes or symptom exacerbations of the disorder; and it must exhibit some degree of stability independent of the symptoms of the disorder (but see Just, Abramson, & Alloy, 2001, for the argument that a vulnerability factor does not need to be immutable). Given these criteria, some research designs are more appropriate than others for testing vulnerability hypotheses (Alloy, Abramson, Raniere, et al., 1999). For example, cross-sectional studies that compare a group with the disorder of interest to a normal control group (and possibly, a group with a different disorder) on several characteristics can generate hypotheses about potential vulnerabilities, but are wholly inadequate for establishing temporal precedence or stability independent of symptoms of the disorder. Designs that compare individuals who have remitted from an episode of the disorder of interest to a normal control group on the potential vulnerability factors or that longitudinally compare individuals with the disorder in their symptomatic versus remitted states are an improvement because they can demonstrate independence of the potential vulnerabilities from the symptoms of the disorder. However, such "remitted disorder designs" cannot distinguish between the alternative possibilities that the characteristics are risk factors for the disorder or consequences ("scars") of the disorder (Just et al., 2001; Lewinsohn, Steinmetz, Larson, & Franklin, 1981). Thus, ideally, a prospective, longitudinal design is needed in which the potential vulnerability factor is assessed prior to the onset of the disorder. Such prospective designs can establish both the vulnerability factor's temporal precedence and independence from symptoms (Alloy, Abramson, Raniere, et al., 1999; Alloy, Abramson, Whitehouse, et al., 1999).
Unfortunately, few studies examining the role of life events as proximal triggers or cognitive styles as distal vulnerabilities for bipolar spectrum disorders have used the preferred prospective designs. Thus, the review here makes note of those studies that do. Indeed, as a group, the bipolar spectrum disorders present especially difficult methodological challenges for conducting tests of vulnerability hypotheses. First, they are highly recurrent with significant interepisode symptomatology and functional impairment. As a consequence, it is very difficult to assess proximal life events or distal cognitive styles at a time when the individual is asymptomatic in order to establish independence of these potential vulnerabilities from symptoms of mania/hypomania or depression. One has to be concerned with the possibility that residual symptoms may bias the assessment of life events or cognitions. Second, bipolar disorders have their initial onset at an early age (mean onset of 14 years old for Cyclothymia; Akiskal et al., 1977,1979). Thus, to truly establish temporal precedence for initial onset of bipolar disorder, one would have to assess life events or cognitive styles in childhood or early adolescence. No study to date has done this. Third, as a consequence of many mood swings and interepisodic symptoms, many bipolar individuals lead chaotic lives. This, in turn, increases the likelihood that they actually contribute to the occurrence of stressors in their lives through poor judgment, poor coping skills, and other symptoms (Alloy, Abramson, Raniere, et al., 1999; Hammen, 1991; Johnson & Roberts, 1995). To deal with this problem, some investigators of life events and bipolar disorders have included only those events that are independent of the participants' behavior, and we note these studies in our review. Given these methodological challenges for vulnerability research, much work remains to be done in investigating the role of cognitive styles and life events as vulnerabilities for bipolar spectrum disorders.
Was this article helpful?
Are You Extremely Happy One Moment and Extremely Sad The Next? Are You On Top Of The World Today And Suddenly Down In The Doldrums Tomorrow? Is Bipolar Disorder Really Making Your Life Miserable? Do You Want To Live Normally Once Again? Finally! Discover Some Highly Effective Tips To Get Rid Of Bipolar Disorder And Stay Happy And Excited Always! Dont Let Bipolar Disorder Ruin Your Life Anymore!