Role of Comorbid Depression and Co-occurring Depressive Symptoms in Outcomes for Anxiety-Disordered Youth Treated with Cognitive-Behavioral Therapy

This study examined the role of comorbid depressive disorders (major depressive disorder or dysthymic disorder) and co-occurring depressive symptoms in treatment outcome and maintenance for youth (N = 72, aged 7–14) treated with cognitive-behavioral therapy for a principal anxiety disorder (generalized anxiety disorder, separation anxiety disorder, or social phobia). Hierarchical linear modeling examined treatment outcome and maintenance in terms of severity of the principal anxiety disorder. Results indicated that higher levels of child-reported depressive symptoms predicted less favorable treatment outcome. Higher levels of mother-reported depressive symptoms predicted less favorable treatment maintenance at a 1-year follow-up. Results suggest that co-occurring depressive symptoms play a role in effective treatment for anxiety-disordered youth and support the merits of treatment adaptations for these youth.     

Redundant information in an observing-response procedure

In three observing-response experiments relevant to the information hypothesis of conditioned reinforcement, the basic procedure was one in which an observing response produced one stimulus on trials that terminated in non-contingent reinforcement and another stimulus on trials that terminated in a brief timeout. In Experiment I, the observing response consisted of a single peck or a short fixed-ratio schedule (FR 3 or FR 6), depending on the type of trial. If the single peck produced the negative stimulus and the fixed ratio produced the positive stimulus, observing responses were maintained. If the single peck produced the positive stimulus and the fixed-ratio produced the negative stimulus, observing responses were not maintained on negative trials. In the second experiment, the response key was either white or dark at the beginning of a trial, indicating whether it was a positive or negative trial. Observing responses continued to be maintained on positive trials but not on negative trials. In Experiment III, only positive or negative trials were scheduled for several sessions. Observing responses extinguished regardless of whether positive or negative trials were scheduled. The results do not support the hypothesis that making the stimuli produced by observing responses redundant will reduce observing responses.     

Acquisition and transfer effects of cued and noncued double alternation schedules with rats

In an attempt to establish patterning, rats were administered eight daily runway trials in a double alternation schedule with distinctive goal events in either a consistent or a varied sequence. Different magnitudes of reward differentiated the reinforced trials, whereas different lengths of confinement in the empty goal box distinguished the nonreinforced trials. During acquisition, rats given the consistent cue sequence “patterned”, whereas the group presented varied cues did not. Subsequently, the Consistent and Varied Cue Groups were subdivided and were administered for 2 days only one of the four acquisition training goal events. During the final 5 days of transfer testing, all subgroups were switched to receiving four daily trials with a second and then a third goal event. In agreement with expectations derived from stimulus aftereffects theory, performance was immediately in accord with the reinforcement contingencies previously established during acquisition training and not the goal event actually presented during testing.     

Some effects of response-dependent clock stimuli in a fixed-interval schedule

Two experiments studied the effects of brief response-dependent clock stimuli in fixed-interval schedules of reinforcement. In the first experiment, two pigeons were exposed to a fixed-interval schedule. Two conditions were compared. In both conditions each peck on the key produced a brief stimulus. In one condition, pecks produced a different stimulus in successive sixths of the interval. This was the clock condition. In the other condition, the same stimulus was produced throughout the interval. Response rates were lower and the pause after reinforcement was longer in the clock condition. In the second experiment, a two-key optional clock procedure was used. Responding on the clock key produced one of three stimuli correlated with the three successive minutes of a fixed-interval schedule. A response on the other key produced grain at the end of the 3 min. When the final stimulus was removed from the situation and pecking produced nothing during the third minute, responding to the clock key declined to a very low rate. When the first two stimuli were removed and the third one replaced, responding to the clock key was resumed.     

Behavioral contrast in rats with different reinforcers and different response topographies

Experiment I demonstrated positive behavioral contrast in rats when one of two qualitatively different reinforcers (milk and pellets) was removed from a component of a multiple schedule. The contrast effect was larger and more enduring when milk was removed. Experiment II showed that the rats spent more time on the side of a shuttle-box on which milk was freely available than on the side on which pellets were freely available. Experiment III, a partial replication of Experiment I, failed to demonstrate the contrast effect of Experiment I. Experiment IV demonstrated contrast when two topographically distinct responses, nose-key poking and lever pressing, were required in different components of a multiple schedule. These results extend the conditions that generate behavioral contrast in rats.