Tests of cognition and their relationship to psychiatric diagnosis and demographic variables.

Psychiatric and control subjects were given a test of cognition consisting of orientation, spelling the word "world" backward, serial 7's test, and recalling three words. The interrelationships among test scores, diagnosis, and demographic variables were determined. Dementia was differentiated from nonorganic psychiatric disorder using only orientation and recall of three words. Depressed, schizophrenic, and bipolar patients were significantly different from controls in their ability to recall three words. In nondemented subjects, the serial 7's test was positively correlated with years of education; spelling "world" backward was negatively correlated with age. Sex, marital status, and orientation showed no significant correlation and hence were bias free.