DSM-IV misses subtle forms of bipolar disorder
medwireNews: Many patients with a major depressive episode also have subthreshold hypomania or mania, say researchers who suggest that the DSM-IV classification may be too narrow to diagnose more subtle forms of bipolar disorder.
The research team, led by Seyed Ali Ahmadi Abhari (Tehran University of Medical Sciences, Iran), assessed 313 patients diagnosed with a major depressive episode and found that 57 (18.2%) met DSM-IV criteria for either bipolar I or II disorder.
However, when they applied Bipolarity Specifier Criteria, which include DSM-IV criteria plus episodes of elevated/irritable mood or increased activity affecting social/occupational functioning, this rate increased to 169 (53.9%).
The findings "suggest that bipolar features are more frequent than symptoms," says the team in the Iranian Journal of Psychiatry.
The Bipolarity Specifier Criteria also showed that manic/hypomanic states were significantly associated with antidepressant therapy, with 115 (36.7%) patients experiencing episodes of elevated or irritable mood triggered by antidepressants.
This suggests the need for caution when routinely prescribing antidepressants for major depressive episodes, say Abhari et al, who recommend detailed information be collected before doing so.
"Present and past history of the patient as well as keen attention to symptoms of bipolar features should be traced attentively," they say, adding that mood stabilizers may be more appropriate for those showing signs of bipolar features.
Other variables associated with bipolarity included mixed mood features, borderline personality disorder, and family history of bipolarity.
"Some hypomanic or even manic symptoms such as mood lability and comorbidity with borderline personality disorder and anxiety disorders manifested more prominently during antidepressant treatment of [major depressive disorder] patients, are indicative of bipolarity," say the researchers.
They note, however, that "nearly none of these variables are included in DSM-IV- [text revised] criteria for diagnosing bipolar disorder which may be considered unjustified and a great pitfall for this classification."
The researchers conclude: "DSM-IV classification appears to be too narrow or rigid to distinguish a more subtle and 'softer' form of bipolar cases from pure unipolar ones."
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Lucy Piper, Senior medwireNews Reporter