Methods of Distinguishing Major Depressive Episodes - Article Example

 Methods of Distinguishing Major Depressive Episodes The purpose of this research study was to assess methods of distinguishing major depressive episodes associated with bipolar disorder from those experienced by patients with chronic depression. Treatments effective in combating depression in patients with major depressive illness may not be effective in patients with bipolar disorder. Therefore, it is extremely important that clinicians distinguish the two different underlying disorders that may be the source of severe depressive episodes in psychiatric patients. Bipolar disorder and major depressive illness are both associated with major depressive episodes. The most common differential diagnosis is based on the presence or absence of episodes of extreme mood elevation or mania. However, patients frequently fail to report manic episodes or may not have ever experienced significant mania at the time of a major depressive episode (Perlis, 2004). This criterion for differential diagnosis is not always reliable and may result in inappropriate or ineffective treatment. This clinical study evaluated additional patient data for differences that might be useful in clinical diagnosis of these Axis I disorders that are both associated with severe depression. Method. This clinical research study involved a comparative assessment of three large multi-center trials of non-psychotic outpatients that compared 477 subjects who were diagnosed as bipolar and 1,074 who were diagnosed with a major depressive disorder. This was a retrospective study of data from multi-center, parallel, randomised, double-blind placebo-controlled trials of patients from the United States. Inclusion criteria for severe depressive illness were a DSM-IV diagnosis of non-psychotic major depressive disorder with a diagnosis of at least moderate depression by Clinical Global Impression (CGI) score 0f 4+ and a Hamilton Depression Rating Scale (HAM-D) of 15+ . Exclusion criteria were age below 18, suicide risk, pregnant or breast feeding women, or substance abusers. Statistical assessments included chi-square data analysis to assess differences in demographic and illness characteristics with significance of p, 0.05. Stepwise logistical regression analysis was used to identify the major predictors of bipolar versus major depressive illness based on data obtained from chi-square analysis. Results A comparative assessment of the two groups of patients indicated that that those with bipolar disorder were more likely to have a family history of bipolar illness than those patients with a major depressive disorder. Both groups had a significant family history of depressive illness. In addition, the group diagnosed with bipolar disorder was found to have an earlier age of onset (average 8 years) and a greater number of depressive episodes than the group of patients diagnosed with major depressive illness. The group with bipolar disorder displayed the emotion of fearfulness as a primary disturbance, whereas the patients with major depressive illness reported feelings of sadness, cognitive deficit, and physical complaints such as gastric, muscular and other physical complaints. On the basis of these findings, the authors showed that a logistic regression model could be used to classify accurately 86.9% of the study subjects. Review of the Discussion. The study authors concluded that the identified differences between these two groups of patients could be very helpful in distinguishing between patients who present with serious depressive episodes associated with bipolar disorder from those whose depression is the result of major depressive illness. The authors emphasised the importance of differential diagnosis of the underlying disorder in patients who present with symptoms of severe depression as the therapeutic strategy is markedly different depending on the nature of the primary disorder. Patients with bipolar disorder who receive anti-depressant medication in the absence of needed mood–stabilisers may experience manic episodes or cycle acceleration/mixed states in a bipolar subgroup. Likewise, mood stabilizers should not be given to patients with major depressive illness. The categorical differences identified represented statistically small differences on an individual level but significant differences were recorded when data from large groups were analysed and compared. The authors stressed that a limitation of the study is that it did not provide data that could be used for differential diagnosis of bipolar II disorder (Akiskal et al., 1995). Moreover, the individual criteria were not sufficiently different to be assessed separately; however, taken together, the combined differences in the assessed categories between these two groups may be useful in predictive diagnoses that distinguish between major depressive illness and bipolar I disorder. Implications of the study. The clinical research study has important implications for differential diagnosis between the underlying causes of severe depressive episodes that require different therapeutic approaches. The identification of a set of clinical differences that may distinguish between these two major forms of depression may provide a useful tool for clinicians as they evaluate patients who present with a primary depressive episode without a confirmed clinical history or diagnosis. These distinctions may facilitate a more rapid, accurate diagnosis and application of a relevant therapeutic intervention. Personal analysis of the study. . As one of the largest studies to compare the symptomatology and patient demographics of two major psychiatric illnesses, it has identified a spectrum of clinical criteria that may be useful in combined assessment in making a differential diagnosis between bipolar I disorder and severe depressive illness. Many recent studies have underscored the importance of a correct psychiatric diagnosis to determine the appropriate therapeutic regimen. The plethora of new drugs available to treat psychiatric illnesses is very promising; however, used inappropriately, these drugs may have severe and even life-threatening consequences. The advent of the new therapeutics makes accurate diagnosis even more essential in order to facilitate the best possible patient outcome. This study effectively highlights the difficulties that may be involved in differential diagnosis of psychiatric illnesses that present with overlapping symptoms. In the absence of a physiological test, patient histories, clinical symptoms and treatment responses are the only diagnostic tools available to the clinician. Studies that compare these clinical parameters and identify reproducible differences may be useful not only in more effective diagnostics but also in addressing the underlying manifestations of psychiatric disease. References Akiskal, H.S., Maser, J.D., Zeller, P.J., Endicott, J., Coryell, W., Keller, M., Warshaw, M., Clayton, P., Goodwin, F.(1995) Switching from "unipolar" to bipolar II: an 11-year prospective study of clinical and temperamental predictors in 559 patients. Arch Gen Psychiatry; 52:114–123. Perkins, R.H., Brown, E., Baker, R. & Nirenberg, A. (2006) Clinical features of bipolar depression versus major depressive disorder in large multicenter trials. Am J Psychiatry, 163:225-231. Perlis, R.H., Miyahara, S., Marangell, L.B., Wisniewski, S.R., Ostacher, M., DelBello, M.P., Bowden, C.L., Sachs, G.S., Nierenberg, A.A.(2004) Long-term implications of early onset in bipolar disorder: data from the first 1,000 participants in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD). Biol Psychiatry, 55:875–881. Read More