ABSTRACT
Mental disorders in general, and mood (affective) disorders in particular, are leading causes of morbidity which affect human populations around the world (1). The term “affective disorder” includes a wide variety of conditions, from mild and common mood variations to some of the most severe episodes of psychotic illness seen in clinical practice. Co-occurrence of other clinical syndromes, such as anxiety or substance abuse, is common. Genetic factors are known to play an important role in influencing susceptibility to all these illnesses (2). Here, discussion will be restricted to bipolar spectrum illness.
