A spectrum model for depressive conditions: extrapolation of the atypical depression prototype

While definition of most depressive disorder is symptom based, atypical depression is defined by personality style as well as by symptoms. If such a model is valid it might have relevance beyond atypical depression. We aimed to pursue the relevance and define the boundaries of a 'spectrum model' for the depressive disorders, where definition is based on personality style, clinical pattern and coping repertoires.

A web-based survey of individuals, who reported one or more episodes of likely clinical depression, was conducted. Some 2692 respondents (with 89% having received an antidepressant, psychotherapy or counselling for such episodes) completed self-report measures on-line. In addition to socio-demographic and clinical data, self-report questionnaires assessed ongoing personality style and coping repertoires in response to depression.

Inter-correlation of personality style and coping repertoire questionnaire data identified 6 relatively distinct 'spectrum' patterns. One was broadly compatible with DSM-IV definition of 'atypical depression', weighted a personality style of 'rejection sensitivity' (itself a facet of a higher-order 'neuroticism' construct), but with a broader set of features being identified. Five other personality-based conditions were defined.

As the study was web-based, we cannot be certain that subjects had experienced depression at a distinctive clinical level. Further depressive symptoms, such as mood reactivity, could be assessed in future studies examining the spectrum model.

As a spectrum model weighting personality is currently allowed to define one depressive condition (i.e. atypical depression), analyses supporting other similar spectrum conditions would argue for extrapolation of the model for definitional, clinical and research purposes.