Bipolar disorders have a long history. Mania and melancholia are the oldest terms and descriptions within psychiatry, having been created in Homeric times by the Greeks, and conceptualized by Hippocrates and his school 2500 years ago. Aretaeus of Cappadocia put melancholia and mania together, because he recognized both psychopathological states as parts of the same disease, thereby giving birth to the bipolar disorders. His formulation stressed that, while mania has various phenomenological manifestations, nevertheless all of these forms belong to the same disease. Some of these special forms of bipolar disorder that are of major clinical and research relevance are the topic of this book.

Even though the three groups of bipolar disorders – mixed states, rapid-cycling, and atypical bipolar disorder – were well known by the nineteenth century, interest accelerated after the psychopharmacological revolution in the middle of the twentieth century. Thus the importance of defining rapid cycling was made clear by the observation that the response to lithium treatment was poorer in patients experiencing four or more episodes per year. The “rediscovery” of mixed states, which were conceptualized by Emil Kraepelin and Wilhelm Weygandt at the end of the nineteenth century, was also associated with problems concerning treatment with antidepressants and mood stabilizers. It has been half a century since the start of the pharmacological revolution. Its consequences across all fields of psychiatry have been enormous: biological research and genetics, treatment and prophylaxis, clinical and prognostic research, and psychopathological and diagnostic approaches.