Strong evidence from multiple peer-reviewed studies and meta-analyses confirms that improving sleep quality significantly reduces anxiety symptoms. However, the claim overstates the case for psychological stress: a 2025 meta-analysis found no significant difference in stress levels compared to standard care when sleep was improved. The sleep-anxiety relationship is also bidirectional, meaning reduced anxiety can itself improve sleep. The claim is well-grounded for anxiety but less conclusively supported for stress reduction specifically.

Multiple large-scale studies and meta-analyses consistently link pre-bed screen use with poorer sleep quality, shorter sleep duration, and delayed sleep onset in adults. A plausible biological mechanism (blue-light-mediated melatonin suppression) supports this association. However, the claim's blanket causal framing overstates the evidence: most supporting studies are observational and cannot prove causation, effects vary by age group (youth studies show weaker or null effects), and factors like content type and in-bed versus pre-bed use matter significantly.