Specific studies on manic and depressive mixed states needed

Evidence to inform the treatment of bipolar mixed states is scarce and specific studies focusing on manic and depressive mixed states are needed, say Australian researchers.Manic and depressive symptoms in mixed state bipolar disorder may co-exist in equal proportions, but usually one component is dominant.Accurate diagnosis of bipolar mixed states is required to enable effective treatment but is often difficult. For example, the symptoms of depressive mixed state are very similar to those of agitated depression.In clinical terms the most common manifestation of mixed state bipolar disorder is the presence of a few features of one pole of the illness within the opposite pole. However, DSM-IV requires a full complement of features of both mania and depression for diagnosis.Various methods for defining or classifying mixed states have been proposed but as yet no consensus has been reached. According to the researchers, it has long been recognised that mixed states are predictive of a poorer response to treatment. For example, there is much evidence to show that patients with euphoric mania respond better to lithium than those with mixed mania. The researchers state that valproate and carbamazepine have similar antimanic efficacy in mixed episodes, with varying efficacy in the treatment of the depressive component.Atypical antipsychotics may also be of benefit in depressive mixed states, however, more evidence of their effectiveness is needed urgently, the researchers say. Electroconvulsive therapy (ECT) has shown efficacy in both the manic and depressive components and, given the increasing realisation of the limitations of antidepressants, its use in mixed states may warrant earlier consideration in clinical algorithms, say the researchers. The researchers state that, although widely used in bipolar disorder, antidepressants have the ability to cause mood instability in vulnerable patients and may precipitate mixed states. In addition, certain adverse effects may be more likely to occur in patients with mixed states.Because studies have focused mainly on mania with depressive symptoms it is not clear if the findings can be applied to depression with manic symptoms. The researchers conclude that trials examining the specificity of various agents in depressive and manic mixed states would be of "great theoretical and practical interest and would provide much more relevant and informative clinical guidelines".Reference...