Descriptive Psychopathology: The Signs and Symptoms of ...

381 Chapter 16: An evidence-based classificationconcordance. The investigators tested several lability models and concluded thatmanic-depressive illness was not simply a more severe form of recurrent depressiveillness, but that nevertheless the two forms exhibit substantial genetic overlap(about 30%). 75In an extensive analysis of the literature of manic-depressive illness, Goodwinand Jamison concluded: 76“Taken together, the data suggest that they [unipolar and bipolar] are best considered as twosubgroups of manic-depressive illness rather than separate and distinct illnesses. The availabledata also support a continuum model, with “pure” bipolar illness at one end and unipolarillness at the other. (p. 65)Since Goodwin and Jamison’s review, the unipolar and bipolar dichotomy hasbeen questioned repeatedly. Melancholic depressions associated with mania orhypomania cannot be distinguished from melancholia without the association. 77Most cross-sectional clinical features do not distinguish a first episode of a recurrentsevere depression from the initial depression in a manic-depressive course. 78Mixed states are common, with manic-like features emerging even in patients withseveral initial episodes of depression. 79Patients initially considered unipolar are commonly re-labeled bipolar. 80 Theapparent pure “polar” forms are recurrent and in succeeding episodes 70% ofpatients initially classified as bipolar experience mostly episodes of depression,while 10–15% of patients with recurrent depressive illness eventually exhibitepisodes of mania, and over half show features of mania when depressed. 81Depression is found to be the predominant and most frequent mood disturbancein bipolar patients, and the depression of bipolar disorder is commonly characterizedas psychotic depression, melancholia, depression with severe psychomotorretardation, or atypical depression.The singularity of manic-depressive illness is described in numerous reports, andthe proposed bipolar I, II and III are a continuum. 82 Cassano et al. (2004)presentedclinical data from 117 patients initially designated as having “remitted recurrentunipolar depression” with 106 said to have bipolar I disorder, and concluded:Cumulatively our empirical findings support a continuous view of the mood spectrum as aunitary phenomenon that is best understood from a longitudinal perspective. Our data suggestthat unipolar disorder and bipolar disorder are not two discrete and dichotomous phenomenabut that mood fluctuations – up and down – are common to both conditions.Laboratory verificationThe pattern of neurobiological markers of mania and severe depression arealike and do not delineate recurrent depressive melancholic illness from manicdepression.DST non-suppression 83 and increased cortisol levels 84 are observed