An evaluation of the DSM-5 rules defining mania and hypomania with identical symptom criteria

BackgroundDSM-IV and DSM-5 provide identical symptom criteria and cut-off scores in defining mania and hypomania, a model seemingly counter-intuitive for classificatory differentiation. We designed a study to examine the impact of such DSM criteria and propose alternative models.MethodsPrevalence and severity of hypo/manic symptoms as measured by the Mood Swings Questionnaire (MSQ) were compared in age and gender-matched bipolar I and II patients. Use of the MSQ allowed both DSM and additional items to be evaluated in terms of their capacity to differentiate the two bipolar conditions.ResultsIn comparison to bipolar II participants, the bipolar I participants reported higher prevalence scores on six MSQ symptoms, severity scores on twelve MSQ symptoms and total MSQ scores. While bipolar I and II participants reported similar prevalence rates of DSM-5 symptoms, bipolar I participants returned higher prevalence rates on five (non-DSM) MSQ items.LimitationsBipolar sub-type was not formally assessed by a structured diagnostic interview. The degree to which assigned MSQ items corresponded with DSM items might not necessarily have high equivalence. The study would have been enriched by evaluating a number of other symptom constructs.ConclusionsFindings suggest several optional approaches to differentiating mania and hypomania. The model we favor is one with a core set of features integral to mania and hypomania that is complemented by certain differentiating features. Psychotic features and over-valued ideas might provide the domain for such differentiation.