Cognitive behavioural therapy for insomnia as an early intervention of mood disorders with comorbid insomnia: A randomized controlled trial.

OBJECTIVE: To evaluate the effectiveness of small-group nurse-administered cognitive behavioural therapy for insomnia (CBTI) as an early intervention of mood disorders with comorbid insomnia. METHODS: A total of 200 patients with first-episode depressive or bipolar disorders and comorbid insomnia were randomized in a ratio of 1:1 to receiving 4-session CBTI or not in a routine psychiatric care setting. Primary outcome was Insomnia Severity Index. Secondary outcomes included response and remission status; daytime symptomatology and quality of life; medication burden; sleep-related cognitions and behaviours; and the credibility, satisfaction, adherence and adverse events of CBTI. Assessments were conducted at baseline, 3, 6, and 12-month. RESULTS: Only a significant time-effect but no group-by-time interaction was found in the primary outcome. Several secondary outcomes had significantly greater improvements in CBTI group, including higher depression remission at 12-month (59.7% vs. 37.9%, χ2 = 6.57, p = .01), lower anxiolytic use at 3-month (18.1% vs. 33.3%, χ2 = 4.72, p = .03) and 12-month (12.5% vs. 25.8%, χ2 = 3.26, p = .047), and lesser sleep-related dysfunctional cognitions at 3 and 6-month (mixed-effects model, F = 5.12, p = .001 and .03, respectively). Depression remission rate was 28.6%, 40.3%, and 59.7% at 3, 6, and 12-month, respectively in CBTI group and 28.4%, 31.1%, and 37.9%, respectively in no CBTI group. CONCLUSION: CBTI may be a useful early intervention to enhance depression remission and reduce medication burden in patients with first-episode depressive disorder and comorbid insomnia.

Sensory eye dominance plasticity in the human adult visual cortex.

Sensory eye dominance occurs when the visual cortex weighs one eye's data more heavily than those of the other. Encouragingly, mechanisms underlying sensory eye dominance in human adults retain a certain degree of plasticity. Notably, perceptual training using dichoptically presented motion signal-noise stimuli has been shown to elicit changes in sensory eye dominance both in visually impaired and normal observers. However, the neural mechanisms underlying these learning-driven improvements are not well understood. Here, we measured changes in fMRI responses before and after a five-day visual training protocol to determine the neuroplastic changes along the visual cascade. Fifty visually normal observers received training on a dichoptic or binocular variant of a signal-in-noise (left-right) motion discrimination task over five consecutive days. We show significant shifts in sensory eye dominance following training, but only for those who received dichoptic training. Pattern analysis of fMRI responses revealed that responses of V1 and hMT+ predicted sensory eye dominance for both groups, but only before training. After dichoptic (but not binocular) visual training, responses of V1 changed significantly, and were no longer able to predict sensory eye dominance. Our data suggest that perceptual training-driven changes in eye dominance are driven by a reweighting of the two eyes' data in the primary visual cortex. These findings may provide insight into developing region-targeted rehabilitative paradigms for the visually impaired, particularly those with severe binocular imbalance.

Dichoptic Perceptual Training and Sensory Eye Dominance Plasticity in Normal Vision.

Purpose: We introduce a set of dichoptic training tasks that differ in terms of (1) the presence of external noise and (2) the visual feature implicated (motion, orientation), examining the generality of training effects between the different training and test cues and their capacity for driving changes in sensory eye dominance and stereoscopic depth perception. Methods: We randomly assigned 116 normal-sighted observers to five groups (four training groups and one no training group). All groups completed both pre- and posttests, during which they were tested on dichoptic motion and orientation tasks under noisy and noise-free conditions, as well as a binocular phase combination task and two depth tasks to index sensory eye dominance and binocular function. Training groups received visual training on one of the four dichoptic tasks over 3 consecutive days. Results: Training under noise-free conditions supported generalization of learning to noise-free tasks involving an untrained feature. By contrast, there was a symmetric learning transfer between the signal-noise and no-noise tasks within the same visual feature. Further, training on all tasks reduced sensory eye dominance but did not improve depth perception. Conclusions: Training-driven changes in sensory eye balance do not depend on the stimulus feature or whether the training entails the presence of external noise. We conjecture that dichoptic visual training acts to balance interocular suppression before or at the site of binocular combination.