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EditorialPsychiatric Diagnosis and the Bipolar Spectrum
Over the years, psychiatry has been susceptible to diagnostic fads. Some of these have been based on theory (overdiagnosis of schizophrenia) or on etiological concepts (overdiagnosis of posttraumatic stress disorder), while others have been based on treatment considerations. Since the introduction of lithium several decades ago, psychiatrists have tended to diagnose bipolar disorder much more frequently. Even after standard diagnostic criteria for schizophrenia were introduced (1), there was a tendency to change the diagnosis of patients with schizophrenia to bipolar disorder. Patients with borderline personality disorder who suffer from frequent mood swings have also been seen as falling within the spectrum of bipolar illness (2). Moreover, it has been claimed that bipolar disorder is common in children (3), mainly in cases formerly diagnosed with conduct disorder or attention-deficit hyperactivity disorder; however, it has never been shown that “bipolar children” evolve into adult bipolar disorder. A paper in last year’s Canadian Journal of Psychiatry (4) suggested that classical bipolar illness should be called “Cade’s disease” and that manic-depression is only one among a wider range of conditions called “bipolar spectrum disorder.” The arguments for a spectrum concept have been based largely on phenomenology and comorbidity, although data from family prevalence, course of illness and treatment response are much less clear (5). Notably, application of the bipolar spectrum concept might increase its overall community prevalence to very high levels, perhaps as high as 20% (6). Pharmacologic dissection can help to determine the boundaries of mental disorders. While lithium and mood stabilizers are most effective for the classical disorder, they are not dramatically effective for personality disorders (7). In children and adolescents, it should be recognized that mood stabilizers have an anti-impulsive effect (8), which is shared with neuroleptics and selective serotonin reuptake inhibitors (SSRIs), that could produce therapeutic results that could have nothing to do with mood. Psychiatrists like to diagnose conditions they can treat. The increase in bipolar diagnoses reflected the great success of lithium. This sort of thing has happened before in the history of our discipline. In the 1940s, when electroconvulsive therapy was shown to be effective for depression, psychiatrists prescribed it indiscriminately to many patients with depressive symptoms. Similar scenarios emerged with the use of neuroleptics, tricyclic antidepressants, and SSRIs. Prescribing patterns have paralleled the susceptibility of psychiatry to diagnostic fads. There was a time when every patient seemed to have “latent schizophrenia,” and another time when everything in psychiatry seemed to be “masked depression.” Now it seems that any patient who describes being in a good mood for too long will be prescribed a mood stabilizer. I believe there has been a rush to judgment about the bipolar spectrum. We need much more evidence before subscribing to a concept that would radically re-define much of psychiatry. References1. Robins E, Guze SB. Establishment of diagnostic validity in psychiatric illness: its application to schizophrenia. Am J Psychiatry 1970;126:107–11. 2. Akiskal HS. The bipolar spectrum—the shaping of a new paradigm in psychiatry. Curr Psychiatry Rep 2002;4:1–3. 3. Sanchez L, Hagino O, Weller E, Weller R. Bipolarity in children. Psychiatr Clin North Am 1999;22:629–48. 4. Ghaemi SN, Ko JY, Goodwin FK. “Cade’s disease” and beyond: misdiagnosis, antidepressant use, and a proposed definition for bipolar spectrum disorder. Can J Psychiatry 2002;47:125–34. 5. Paris J. Bipolar or borderline? Harv Rev Psychiatry. Forthcoming. 6. Judd LL, Akiskal HS. The prevalence and disability of bipolar spectrum disorders in the US population: re-analysis of the ECA database taking into account subthreshold cases. J Affect Disord 2003;73:123–31. 7. Soloff P. Psychopharmacological treatment of borderline personality disorder. Psychiatr Clin North Am 2000;23:169–92. 8. Swann AC. Neuroreceptor mechanisms of aggression and its treatment. J Clin Psychiatry 2003;64(Suppl 4):26–35. (CPA Bulletin 2004; 36[3]:3) |