The value of psychiatric diagnosis is challenged by comorbidities and outcome prediction compared with symptom clusters and the role of common personality factors, such as impulsivity. The usuall clinical scales such as BPRS, HAM-D, YMRS or MMSE often mislead away from important symptoms or behaviors, since their validities are compared to valid classifications and diagnosis and do not include important coommon pathways to clinical manifestations and outcome.

Using prospective design the study evaluates diagnosis, results of clinical scales (BPRS, HAM-D, YMRS and MMSE) and impulsivity (BIS) to retrospectivelly assessed course of illness and outcome of index episode in adult patients presenting with acute episode or worsening of schizophrenia, unipolar depression, bipolar disorder and dementia.

120 patients were included (30 in each diagnostic group) in the study, that is on-going at present. We found no correlation between past and present outcome and diagnosis, the corrleations were confirmed to clinical scales used, but the strongest corrleations were found between impulsivity and outcome in all four patient groups.

Current diagnostic systems are limited in longitudinal and outcome strenght. Other symptom clusters and impulsivity seem to predict outcome more consistently.