Therapeutic and genetic prospects of an atypical affective disorder

The utility of bipolar type II affective disorder subgrouping is discussed. There is low diagnostic agreement among clinicians for this putative condition. However, the clustering of cases in families and the poor response to standard treatments suggest that it is a distinct subgroup. The clinical features of the depressive phase of this condition including chronicity, intermittency, hyperphagia, hypersomnia, and reactivity relate it to the constructs of "hysteroid dysphoria," atypical depression, and seasonal affective disorder. Its association to several abnormal motivated behaviors such as alcoholism and eating disorders allows the speculation that a distinct morbid mechanism involving serotonin may underlie it and that new serotonin reuptake blocking drugs may be useful in treating it. Finally, the genetic identity of this subgroup in all likelihood will be established or rejected by genetic linkage studies utilizing the restriction fragment length polymorphism map of the genome.