The spectrum of mood disorders

The problem of classifying mood disorders still lacks an acceptable solution. Interrater reliability studies have shown that this problem is more prevalent in mood disorders compared with other psychiatric conditions. Historically the problem originates from the distinction between Geisteskrankheiten and Gemütskrankheiten (mental and mood disorders) because the domain covered by the word mood has been progressively reduced. The fact that neurotic disorders are "emotional disorders" further complicates this field. The words anxiety and depression refer to a disorder, to a symptom, and to everyday feelings. A failure or difficulty in the distinction between these three meanings leads to nosological confusion. In recent years, the notion of a spectrum of mood disorders has gained acceptance. According to this, the diverse disorders are placed on a point that is more or less close to one of the extremes. Something similar occurs in the unipolar-bipolar distinction, in which the bipolar II or atypical and bipolar III occupy a central place on the spectrum. Cluster analysis and other mathematical techniques have helped to clarify the outlook, but there is a need for a biopsychosocial perspective and for a deeper understanding of the natural history of these disorders.