Mental and psychomotor speed in depression and mania.

Mental and psychomotor speed scores were obtained for three affectively ill groups of bipolar depression, unipolar depression and bipolar mania, and three corresponding recovered groups. Comparisons were made among ill groups, among recovered groups, and between ill and recovered groups for each illness type. The following conclusions were drawn: 1. Though manic patients solve problems quicker than those of either depressed group, they do not differ much from normals. 2. With stress to work faster, the pateints in the two depressed groups can quicken their speed of work and bring it up to the level of the manic patients, even thought the latter also increase their speed. 3. On a psychomotor speed task, the bipolar dipressives are significantly slower than the manics and the unipolar depressives, who do not differ. 'Internal distraction' causes a slight increase in speed in all three groups, with no significant difference, but 'external distraction' speeds up the bipolar groups and slows down the unipolar depressives resulting in significant differences between the bipolars on the one hand and the unipolars on the othbr. 4. All recovered groups perform at the same level on all measures. 5. Comparison between ill and recovered groups seems to indicate that a manic illness does not affect mental ro psychomotor speed significantly when tested objectively. Unipolar depression also does not seem to affect speed functions very significantly. Thus only bipolar depressive patients seem to show true retardation, and manic patients do not show the opposite of retardation.