Since ancient times has there been knowledge of affective temperaments - with descriptions ranging from Hippokrates and Galenus to Kraepelin and Kretschmer (in the early 20th century). Whilst temperament can be broadly defined as “an individual's characteristic or habitual inclination or mode of emotional response”, there are three different underlying concepts of temperament, which are based on (1) psychopathology (e.g. Kretschmer or Akiskal), (2) neurobiology (e.g. Eysenck or Gray) or (3) developmental observations (e.g. Chess or Kagan). Despite some undisputable overlap, it is noteworthy that “temperament” differs significantly from “character” or “personality”. Recent research has confirmed that there is a genetic basis to temperament. For example, links to the serotonin transporter gene 5HTTLPR polymorphism have been made. In regards to temperament other neurobiological systems including the HPA axis have been studied as well as issues of gender, ethnicity and psychosocial factors

There exist several instruments to assess temperaments in their various conceptualizations. The TEMPS-A scale and the TEMPS-I interview reflect the temperament concept as outlined by Akiskal and others in Memphis, Pisa, San Diego and elsewhere. It assesses 5 forms of temperament: depressive, anxious, cyclothymic, irritable and hyperthymic. Translations into Italian, German, Hungarian, Turkish, French, Portuguese and other languages are available.

The relation between affective disorders and temperaments seems to be complex. There is increasing evidence that temperaments may be subclinical forms of affective disorders or that they might represent vulnerability to affective disorders. Therefore, they belong to a broad affective (bipolar) spectrum. Furthermore, they seem to mitigate course and symptomatology of affective disorders. Several studies have shown that mixed episodes go along with distinct temperament profiles (high depressive, anxious, cyclothymic or irritable and low hyperthymic temperament), so that acute psychopathology and underlying temperament “mix”. Furthermore, temperaments seem to be factors, which may explain difficult-to-treat cases, as they may reflect aspects of comorbidity of affective disorders - for example with anxiety disorders or substance abuse, or may explain personality pathology including some forms of borderline personality disorders. From a theoretical background one can speculate about the relevance of temperaments for treatment strategies. Nevertheless, this area lacks empirical studies.

Altogether the concept of temperaments is an interesting perspective to better understand affective disorders. While historical and clinical knowledge in this area is plentiful, nowadays there is also emerging empirical support for this concept.