Subsyndromal AMDP scales to distinguish pathogenetically homogenous subgroups of affective disorders

The AMDP is a comprehensive rating system comprising 140 psychopathological and somatic symptoms, which can be grouped to 9 syndromal scales designed to obtain an optimal separation of diagnostic entities. In order to distinguish clinically more homogenous subgroups of patients within a diagnostic entity, e.g., for genetic association studies, the syndromal scales are less appropriate. We conducted combined factor- and item-analyses in about 300 patients with affective disorders in order to identify subsyndromal scales (from M.A.R.S. database).

Seven factors could be consistently extracted. Principal component analysis revealed three orthogonal subgroups of patients. The first subgroup characterized by depressive mood, retardation and lack of drive shows the lowest degree of improvement and can be regarded as relatively refractory to antidepressive treatment. The second subgroup characterized by agitation and insomnia shows a favorable treatment response. The third subgroup characterized by vegetative and anxiety symptoms exhibits a moderate treatment response. Replication and validation of these results are required and already ongoing.