Efficacy of Guided iCBT for Depression and Mediation of Change by Cognitive Skill Acquisition

Guided internet CBT (iCBT) is a promising treatment for depression; however, it is less well known through what mechanisms iCBT works. Two possible mediators of change are the acquisition of cognitive skills and increases in behavioral activation. We report results of an 8-week waitlist controlled trial of guided iCBT, and test whether early change in cognitive skills or behavioral activation mediated subsequent change in depression. The sample was 89 individuals randomized to guided iCBT (n = 59) or waitlist (n = 30). Participants were 75% female, 72% Caucasian, and 33 years old on average. The PHQ9 was the primary outcome measure. Mediators were the Competencies of Cognitive Therapy Scale–Self Report and the Behavioral Activation Scale for Depression–Short Form. Treatment was Beating the Blues plus manualized coaching. Outcomes were analyzed using linear mixed models, and mediation with a bootstrap resampling approach. The iCBT group was superior to waitlist, with large effect sizes at posttreatment (Hedges’ g = 1.45). Dropout of iCBT was 29% versus 10% for waitlist. In the mediation analyses, the acquisition of cognitive skills mediated subsequent depression change (indirect effect = -.61, 95% bootstrapped biased corrected CI: -1.47, -0.09), but increases in behavioral activation did not. iCBT is an effective treatment for depression, but dropout rates remain high. Change in iCBT appears to be mediated by improvements in the use of cognitive skills, such as critically evaluating and restructuring negative thoughts.     

Low Working Memory rather than ADHD Symptoms Predicts Poor Academic Achievement in School-Aged Children

This study examined whether working memory (WM), inattentive symptoms, and/or hyperactive/impulsive symptoms significantly contributed to academic, behavioral, and global functioning in 8-year-old children. One-hundred-sixty 8-year-old children (75.6% male), who were originally recruited as preschoolers, completed subtests from the Wechsler Intelligence Scale for Children–Fourth Edition, Integrated and Wechsler Individual Achievement Test–Second Edition to assess WM and academic achievement, respectively. Teachers rated children’s academic and behavioral functioning using the Vanderbilt Rating Scale. Global functioning, as rated by clinicians, was assessed by the Children’s Global Assessment Scale. Multiple linear regressions were completed to determine the extent to which WM (auditory-verbal and visual-spatial) and/or inattentive and hyperactive/impulsive symptom severity significantly contributed to academic, behavioral, and/or global functioning. Both auditory-verbal and visual-spatial WM but not ADHD symptom severity, significantly and independently contributed to measures of academic achievement (all p < 0.01). In contrast, both WM and inattention symptoms (p < 0.01), but not hyperactivity-impulsivity (p > 0.05) significantly contributed to teacher-ratings of academic functioning. Further, inattention and hyperactivity/impulsivity (p < 0.04), but not WM (p > 0.10) were significantly associated with teacher-ratings of behavioral functioning and clinician-ratings of global functioning. Taken together, it appears that WM in children may be uniquely related to academic skills, but not necessarily to overall behavioral functioning.