Use of memory tests in differentiating organic disorder from depression.

Although memory tests are commonly used to help differentiate organic conditions from depression, the extent to which depression might influence test performance is unclear. Comparison of the performances of normal, brain-damaged, and depressed subjects on a battery of verbal and visual memory tests revealed that the incidence of impairment amongst the depressed subjects was not significantly greater than amongst normal subjects on the majority of measures, and that within the depressed group, the degree of depression was not related to poor test performance. The brain-damaged group displayed a significant incidence of impairment on all measures, and a significantly greater incidence than the depressed group on the majority of measures. It is concluded that memory tests have a useful role to play in differential diagnosis.