DEFINING MELANCHOLIA - PROPERTIES OF A REFINED SIGN-BASED MEASURE

We hypothesised that psychomotor disturbance is specific to the melanc holic subtype of depression and capable of defining melancholia more p recisely than symptom-based criteria sets. We studied 413 depressed pa tients, and examined the utility of a refined, operationally driven se t of clinician-rated signs, principally against a set of historically accepted symptoms of endogeneity. We specified items defining psychomo tor disturbance generally as well as those weighted either to agitatio n or to retardation. We demonstrated the system's capacity to differen tiate 'melancholic' and 'non-melancholic' depression (and the comparab le success of DSM-III-R and Newcastle criteria systems) by reference t o several patient, illness and treatment response variables, to an ind ependent measure of psychomotor disturbance (reaction time) and to a b iological marker (the dexamethasone suppression test).