The clinical science of euthymia: A conceptual map.

Euthymia is a trans-diagnostic construct characterized by lack of mood disturbances; presence of positive affect; balance of psychological well-being dimensions, flexibility, consistency, and resistance to stress. The aim of this critical review is to draw a conceptual map of euthymia. Relationships with other constructs, continuum between euthymia and dysthymia with discomfort as an intermediate area, associations with lifestyle, clinimetric assessment, role of psychotherapeutic interventions, establishment of therapeutic targets, and neurobiological mechanisms are discussed. The model is based on the bipolar nature of well-being dimensions. Euthymia means using allostasis optimally and maintaining a healthy balance that promotes positive aspects of brain and body health through health-promoting behaviors. It may provide a framework for a renewed definition of recovery, for measuring treatment outcome and for targeting interventions, including the sequential administration of therapeutic components. Clinical assessment requires a clinimetric approach encompassing a broad range of aspects, such as allostatic load and lifestyle behaviors, all interacting with each other and contributing to the euthymia/dysthymia balance. Clinimetric indices for assessing euthymia (the Clinical Interview for Euthymia and the Euthymia Scale) and related constructs (the Clinical Interview for Dysthymia and the Semi-Structured Interview for the Diagnostic Criteria for Psychosomatic Research) are presented here. Well-Being Therapy, a psychotherapeutic strategy specifically aimed at pursuing euthymia, relies on self-observation of well-being episodes using a structured diary as a distinct therapeutic ingredient. The clinical science of euthymia may unravel innovative approaches to assessment and treatment of psychiatric and medical disorders, according to a unitary conceptual framework.