Modifying behavioral variability in moderately depressed students.

This study asked whether response sequences generated by moderately depressed students are more repetitive than those generated by nondepressed students and whether sequence variability can be increased in those identified as depressed. Seventy-five undergraduate students completed the Center for Epidemiological Studies Depression Scale (CES-D) and were divided into moderately depressed and nondepressed groups. Some of the students had received class instruction concerning behavioral variability; others did not. All students participated in a two-phase, computer-game procedure in which response-sequence variability was measured. When reinforcement was provided independently of sequence variability, the depressed participants responded more repetitively than did the nondepressed. When high sequence variability was required for reinforcement, variability increased significantly in all participants, with the depressed achieving the same high levels as the nondepressed. The students who had been instructed about variability responded more variably throughout than the noninstructed. Therefore, both direct reinforcement and instruction increased behavioral variability of depressed individuals, a goal of some therapies for depression.