So reading the actual paper suggests that the article's summary and title is poor / clickbait. This paper does not go into much testing of changing the wake time. Instead it looks at correlations of life-long earlier wake times and suggests that studying the article's claimed effect (earlier sleep times) could be worthwhile.
Several TL;DR quotes:
>Our data are consistent with results from a recent randomized clinical trial7that shifted the sleep timing of individuals withan evening diurnal preference. The multifaceted intervention targeted sleep timing, meal timing, light exposure, caffeine in-take, napping behavior, and exercise behavior. This intervention resulted in a mean 2-hour advance in sleep-wake timing and advanced the dim light melatonin onset, a circadian rhythm timing marker. There was no effect on sleep duration or the time between sleep onset and dim light melatonin onset timing,which suggests the absence of sleep deprivation or worsening of circadian misalignment as a consequence of this intervention.7Participants allocated to the intervention arm had improvements in the overall Depression, Anxiety, and Stress Scale score, as well as the depression and stress subscale scores.
>While this trial also lends support to a causal protective effect of morningness on mood,the study was small (n = 22) and did not assess hard clinical endpoints. In contrast, our analysis tested the association with life-long modification of diurnal preference and assessed the clini-cal end point of MDD diagnosis. Taken together, our results suggest that interventions such as those implemented in this trial7may be worth scaling to larger clinical trials
>This 2-sample MR analysis found robust genetic evidence for a protective association between earlier diurnal preference with lower MDD risk, and contextualized this association using an objective sleep timing measure. The findings support further investigation in the form of randomized clinical trials of sleep timing interventions for the prevention of MDD.
