Cannabis users often say the drug helps them blunt stressful memories. A 2026 randomized trial of 36 healthy adults tested low-dose oral THC against placebo during retrieval of a standardized lab stressor, and on every subjective and physiological measure that mattered, THC did nothing.1 Research Highlights 36-adult, 3-arm RCT: participants got placebo, 5 mg oral …
A 2026 medRxiv meta-analysis of 27 trials found that transcranial direct current stimulation added to cognitive training improved global cognition immediately after treatment by SMD 0.36 compared with cognitive training alone.1 The signal was small, short-term, and rated very low certainty, so it is not evidence that tDCS is a durable cognitive-rehabilitation shortcut. Research Highlights …
A 2026 PREDIMED-Plus cohort analysis linked higher olive-oil intake with 2-year cognitive preservation in 656 older adults, with each 10 g/day increment associated with higher global cognition change compared with lower intake (beta 0.044 z-score; 95% CI 0.013 to 0.075; p = 0.006).1 The more specific signal favored virgin olive oil and gut-microbiome diversity, while …
A longitudinal MIDUS analysis involving 840 adults found that loneliness scores higher than a person's objective social-isolation score were linked to later cognitive impairment mainly through chronic disease burden, while the allostatic-load pathway was weaker than the chronic-disease pathway and not statistically confirmed for the main cognitive outcomes.1 Research Highlights Loneliness was separated from isolation: …
A 2026 controlled study of 96 people found severe long-COVID fatigue across 3 validated fatigue scales, but the tested peripheral inflammation, cellular-stress, neuroprotection, and autoimmunity markers did not significantly differ by group or explain fatigue severity.1 The finding argues against a simple blood-marker story, not against the reality of long-COVID fatigue. Research Highlights Fatigue was …
A 2026 PLOS One machine-learning study reported 95.0% accuracy for a hybrid FT-Transformer plus long short-term memory (LSTM) model predicting student mental-health risk. The technical result is strong inside the dataset, but the clinical claim is still limited because the labels came from repository data rather than prospective clinical diagnosis.1 Research Highlights 95.0% accuracy was …
A Wuhan cohort of 2,210 pregnant women found that mid-pregnancy sleep disturbance was common enough to screen for and associated with several birth-outcome signals. Depressive symptoms, pre-pregnancy alcohol use, and moderate-to-severe vomiting raised sleep-disturbance odds, while higher dietary variety was protective.1 Research Highlights 18.14% had sleep disturbance: Pittsburgh Sleep Quality Index (PSQI) scores greater than …