Sub-grouping non-melancholic major depression using both clinical and aetiological features

In previous papers we have considered the extent to which two contrasting analytic approaches, examining reported clinical symptom variables alone and aetiological variables alone, assist definition of subgroups of non-melancholic major depression. Here, we address the same objective but combine both sets of variables, and contrast the combined solution with each of the contributing ones.

We study a sample of 185 subjects with a putative non-melancholic major depressive disorder, with analyses involving 13 aetiological and 38 symptom variables.

A four-class subgrouping was derived by use of a cluster analytic technique, with 'neurotic depression', non-anxious 'depressed', 'situational' and 'residual' groups. The largest group comprised 'neurotic depression' subjects, with characteristics compatible with a spectrum disorder encompassing both clinical features as well as an underlying temperament and personality style marked by anxiety.

Comparative advantages and properties of the three differing analytic approaches to defining 'meaningful' non-melancholic major depressive subgroupings are considered. As a 'neurotic depressive' class has been consistently identified across those three approaches, but with quite varying numbers of subjects circumscribed, it is clearly a 'fuzzy' entity which may benefit from a dimensional approach to its measurement. As many of the non-melancholic groupings appear secondary to a substantive predisposing factor such as anxiety or disordered personality functioning, the clinical importance and treatment utility in identifying and circumscribing such classes are clearly supported.