Mind

1. Mindwell supported · human dataAdded 5 October 2026

   Cannabis users show double the odds of committing violence

   Results pooled from 63 studies covering 265,079 people link cannabis use to roughly double the odds of perpetrating violence in the general population, rising to 3.75 times the odds for violence leading to a criminal conviction. Cannabis users also had 1.49 times the odds of becoming victims of violence, a risk more pronounced in females.

   ⚠What it shows: A strong and consistent association, but not proof of cause: results pooled from 63 studies of 265,079 people, many of them one-off snapshots that cannot show whether cannabis use or violence came first. The link survived in studies that followed people over time, though it was considerably smaller there.Meta-analysis · Psychol Med

   Full breakdown →Cannabis use is associated with increased risk of violence: A systematic review and meta-analysis. Psychol Med 2026
2. Mindpreliminary · human dataAdded 4 October 2026

   Meditation and relaxation nudge blood pressure down even when it is normal

   Pooled results from 22 randomised trials in up to 3089 healthy adults without hypertension found that stress management techniques modestly lowered blood pressure: mind-body exercise cut systolic pressure by 2.17 mmHg, meditation by 1.49 mmHg and relaxation by 4.76 mmHg compared with controls.

   ⚠What it shows: Credible but modest: results pooled from 22 trials in up to 3089 healthy adults all point the same way, and the drops are a few points of pressure at most. The techniques and trial designs varied widely, so the exact size of the benefit is uncertain.Review · J Hum Hypertens

   Full breakdown →Breathwork for Recovery and Stress →Heart Age Calculator →Effect of interventions for stress management on blood pressure changes in healthy adults: a systematic review and meta-analysis. J Hum Hypertens 2026
3. Mindwell supported · human dataAdded 30 September 2026

   Aerobic exercise works best for minds showing early decline

   Pooled results from 22 trials found exercise therapy improved global cognitive function and reduced depression in older adults with mild cognitive impairment. Aerobic exercise was the most effective type, while multicomponent and neuromotor exercise did not improve cognition, and cognitive gains grew with higher exercise frequency.

   ⚠What it shows: A reasonably strong signal: results pooled from 22 trials in older adults with mild cognitive impairment showed a meaningful cognitive benefit. The depression finding rests on just 7 of those trials, and the studies varied in the exercise types and doses they tested.Meta-analysis · Arch Gerontol Geriatr

   Full breakdown →Executive function explained →Effects of exercise therapy on global cognitive function and, depression in older adults with mild cognitive impairment: A systematic review and meta-analysis. Arch Gerontol Geriatr 2023
4. Mindpreliminary · human dataAdded 29 September 2026

   Mood struggles shadow type 2 diabetes in more than four in ten adults

   In pooled data from 34 studies of 21,024 adults with type 2 diabetes, 43.82% screened positive for anxiety symptoms and 41.83% for depressive symptoms. The estimates varied widely between studies and reflect questionnaire results, not diagnosed disorders.

   ⚠What it shows: Treat the exact figures loosely: this pools 34 studies covering 21,024 people, but the studies disagreed with each other so much that the authors warn the averages are rough summaries rather than universal rates. These were symptom questionnaires, not clinical diagnoses.Review · J Diabetes Metab Disord

   Full breakdown →Pooled prevalence of anxiety and depressive symptoms among adults with type 2 diabetes: a systematic review and meta-analysis. J Diabetes Metab Disord 2026
5. Mindwell supported · human dataAdded 28 September 2026

   Exercise eases depression, and a brain growth factor may explain why

   Pooled results from 12 randomised trials covering 757 adults with major depression found exercise training reduced depressive symptoms and raised circulating BDNF and kynurenine. Improvements in BDNF, kynurenine and interleukin-6 tracked with the drop in symptoms, hinting at how exercise works as an antidepressant.

   ⚠What it shows: The mood benefit rests on pooled trials, but only 12 of them with 757 people, and the biomarker link comes from correlations across those trials rather than a direct test. Treat the BDNF story as a promising lead, not a settled mechanism.Meta-analysis · J Affect Disord

   Full breakdown →Effects of exercise training on inflammatory, neurotrophic and immunological markers and neurotransmitters in people with depression: A systematic review and meta-analysis. J Affect Disord 2023
6. Mindwell supported · human dataAdded 27 September 2026

   Exercise eases anxiety even when it is a diagnosed disorder

   In a meta-analysis of six randomised trials covering 262 adults with diagnosed anxiety or stress-related disorders, exercise reduced anxiety symptoms significantly more than usual treatment or control conditions, with a moderate effect size.

   ⚠What it shows: Encouraging but built on a small base: results pooled from six trials covering 262 adults with diagnosed anxiety or stress-related disorders. The average benefit was moderate, but with so few trials the true size remains uncertain.Meta-analysis · Psychiatry Res

   Full breakdown →Recovery Readiness Index →An examination of the anxiolytic effects of exercise for people with anxiety and stress-related disorders: A meta-analysis. Psychiatry Res 2017
7. Mindwell supported · human dataAdded 27 September 2026

   Cannabis cues grip the brain harder than users feel they do

   Pooled results from 12 studies covering 393 regular cannabis users found that cannabis cues triggered moderate craving reactions overall, and that brain-wave responses to the cues were large while self-reported craving and heart rate responses were far weaker.

   ⚠What it shows: Solid as summaries go: results pooled from 12 studies of 393 regular users, mostly teens and young adults, with no sign that negative findings were buried. The physical measures disagreed with each other a lot, so treat the striking brain-wave figure as a rough size rather than a precise one.Meta-analysis · Addiction

   Full breakdown →Craving cannabis: a meta-analysis of self-report and psychophysiological cue-reactivity studies. Addiction 2016
8. Mindpreliminary · human dataAdded 26 September 2026

   Exercise leaves two different fingerprints on the brain's working memory

   Exercise appears to reshape the brain's working memory circuits in two distinct ways: pooled imaging data from 11 studies found training programmes increased cerebellum activity and quietened the thalamus, while long-term exercisers showed an entirely different, non-overlapping pattern of brain activation.

   ⚠What it shows: Treat this as an early map rather than settled science: it pools brain scans from only 11 studies and 403 people, and the short-term and long-term patterns did not overlap, so how one becomes the other is anyone's guess.Review · Brain Sci

   Full breakdown →Executive function explained →Exercise Modulates Working Memory-Related Brain Activation Through Bidirectional Neural Mechanisms: An ALE Meta-Analysis of Longitudinal and Cross-Sectional fMRI Studies. Brain Sci 2026
9. Mindpreliminary · human dataAdded 22 September 2026

   Box breathing calms the mind, but your heart may not notice

   A sweep of randomised trials found box breathing offers short-term relief for perceived stress, anxiety and mood, but only eight trials qualified and its effects on heart rate variability and cortisol were absent or inconsistent.

   ⚠What it shows: Worth a measured read: a sweep of all the studies on box breathing turned up just eight trials, in groups ranging from healthy adults to postpartum women, using different routines. The calm it delivered was short-term and the body's stress chemistry mostly did not follow.Review · Appl Psychophysiol Biofeedback

   Full breakdown →Breathwork for Recovery and Stress →Systematic Review of Randomised Controlled Trials Evaluating Box Breathing for Stress, Autonomic, and Clinical Outcomes. Appl Psychophysiol Biofeedback 2026
10. Mindpreliminary · human dataAdded 22 September 2026

    Virtual reality training gives older brains a small cognitive lift

    A meta-analysis of 31 randomised trials found virtual reality-based training produced small but significant improvements in older adults' global cognition and executive function compared with conventional training or information-based treatment, though the evidence was graded low to very low.

    ⚠What it shows: Encouraging but low certainty: results pooled from up to 20 trials covering 876 older adults show small gains, yet the studies disagreed with each other considerably and the authors grade the evidence low to very low, so better trials could shrink the effect.Meta-analysis · J Aging Phys Act

    Full breakdown →Executive function explained →The Effects of Virtual Reality Training on Cognition in Older Adults: A Systematic Review, Meta-Analysis, and Meta-Regression of Randomized Controlled Trials. J Aging Phys Act 2024
11. Mindpreliminary · human dataAdded 22 September 2026

    Exercise lifted mood within three months, but memory gains may need longer

    In a three-month randomised trial of 52 healthy middle-aged adults, an instructor-led live online exercise programme reduced depressive symptoms but did not improve pattern separation, the memory measure it was primarily designed to shift. Participants' blood also changed in ways that influenced hippocampal progenitor cells in a lab assay.

    ⚠What it shows: Promising but small: one three-month trial in 52 healthy middle-aged adults, and the brain-cell findings came from a laboratory dish assay using participants' blood, not from measuring anyone's brain. The main memory test did not improve, so any cognitive benefit remains unproven.Study · NPJ Aging

    Full breakdown →Effects of a three-month exercise programme on cognition, mood and neurogenesis: the NeuroFit randomised controlled trial. NPJ Aging 2026
12. Mindwell supported · human dataAdded 15 September 2026

    Depression dampens the body's stress response, it does not amplify it

    A meta-analysis of 126 studies found depression is associated with blunted, not exaggerated, physiological responses to acute mental stress, driven mainly by smaller cardiac and blood-flow reactions. Heart rate variability and stress-hormone responses showed no significant link.

    ⚠What it shows: A real but small signal: pooled results from 126 studies tied current depression to slightly muted heart and circulation responses during lab stress tests. These are links rather than causes, so nobody can say whether the blunted response leads to depression or follows from it.Meta-analysis · Psychol Bull

    Full breakdown →Cortisol explained →Physiological responses to acute psychological stress as a biomarker for depression: A systematic review and meta-analysis. Psychol Bull 2026
13. Mindpreliminary · human dataAdded 11 September 2026

    Exercise and brain training both nudge cognition in early memory decline

    Results pooled from randomised trials suggest both structured cognitive training and physical exercise modestly improve global cognitive function in people with mild cognitive impairment; cognitive training also showed weaker benefits for executive function and delayed memory.

    ⚠What it shows: Encouraging but modest: results pooled from a set of trials in people diagnosed with mild cognitive impairment, and the authors themselves call the memory and executive function findings weak. The trials varied enough in design that better standardised studies are still needed.Meta-analysis · J Alzheimers Dis

    Full breakdown →Executive function explained →Non-pharmacological interventions for patients with mild cognitive impairment: a meta-analysis of randomized controlled trials of cognition-based and exercise interventions. J Alzheimers Dis 2014
14. Mindpreliminary · human dataAdded 10 September 2026

    Strapping on a VR headset to exercise eased depression in trials

    Across 12 pooled randomised trials, exercise delivered through virtual reality significantly reduced depression compared with control conditions, though the certainty of the evidence was graded very low.

    ⚠What it shows: Promising but shaky: 12 pooled trials pointed the same way and the result held up when individual studies were removed, but the studies disagreed with each other in who they enrolled and how, and the authors rate their confidence in the finding as very low.Meta-analysis · BMC Psychiatry

    Full breakdown →Virtual reality-based exercise interventions for the treatment of depression: a systematic review and meta-analysis of randomized controlled trials. BMC Psychiatry 2026
15. Mindpreliminary · human dataAdded 8 September 2026

    Exercise eased students' depression, but the evidence base is shaky

    Pooled results from 22 trials in 1255 college students with depressive symptoms suggest exercise may meaningfully reduce depression scores, with possible benefits for anxiety and physiological markers too, though the certainty of the evidence is low.

    ⚠What it shows: Promising but shaky: results pooled from 22 trials in 1255 students all point the same way, yet the underlying studies were weak enough that the authors rate their own confidence in the depression finding as low, and even lower for the biological markers. The true effect could be a good deal smaller than the headline figures suggest.Review · Acta Psychol (Amst)

    Full breakdown →Effects of exercise on depression, anxiety, and physiological/biochemical markers in college students with depressive symptoms: A three-level meta-analysis. Acta Psychol (Amst) 2026
16. Mindwell supported · human dataAdded 5 September 2026

    A few months of exercise eased midlife anxiety; a year of it did not

    Pooled results from ten randomised trials in 1463 midlife and older women found that programmed exercise lasting 12 weeks to 4 months reduced mild-to-moderate anxiety symptoms, while longer programmes running 6 to 14 months showed no reduction at all.

    ⚠What it shows: Decent evidence with one wobble: results pooled from ten trials in 1463 midlife and older women, and the benefit for the shorter programmes only just cleared statistical significance. Why year-long programmes showed nothing is still unexplained.Meta-analysis · Climacteric

    Full breakdown →Heart Rate Zone Calculator →The effect of programmed exercise over anxiety symptoms in midlife and older women: a meta-analysis of randomized controlled trials. Climacteric 2018
17. Mindpreliminary · human dataAdded 5 September 2026

    Mindfulness courses lower cortisol, not just how stressed you feel

    Across 39 trials with 2,059 participants, mindfulness-based stress reduction programmes lowered cortisol, and beat control conditions in head-to-head comparisons. The effect was modest and varied considerably between studies.

    ⚠What it shows: A solid overall signal: results pooled from 39 trials in 2,059 people show a real but modest drop in cortisol, clearest in properly controlled trials and smaller when mindfulness was compared against other active programmes. The studies disagreed with each other for reasons the analysis could not explain.Study · Health Psychol

    Full breakdown →Cortisol explained →Mindfulness-based stress reduction interventions and cortisol regulation: A systematic review and meta-analysis. Health Psychol 2026
18. Mindpreliminary · human dataAdded 5 September 2026

    Most people miss their exercise goals, and prescribed targets fare worst

    Across 30 low risk of bias trials of physical activity programmes, most participants failed to achieve their activity goals at every timepoint, with failure rates between 57.9% and 77.0%, and achievement declined further over time. Goals people set themselves, or set collaboratively, were achieved more often than goals prescribed to them.

    ⚠What it shows: A thorough sweep of all the studies on this, pooling 89 trials of 10,219 people, with the main analysis limited to the 30 most trustworthy studies. It measures goal achievement inside structured programmes, so it may not describe targets you set entirely on your own.Review · Health Psychol Rev

    Full breakdown →The rates with which individuals fail versus achieve physical activity goals: a systematic review and meta-analysis of randomised controlled trials. Health Psychol Rev 2026
19. Mindpreliminary · human dataAdded 2 September 2026

    Gratitude journals moved heart risk factors, but nobody knows for how long

    A narrative review of 18 randomised trials of positive psychology programmes, including gratitude journaling, optimism training and mindfulness delivered in person, in hybrid form or digitally over 6 to 12 weeks, reported consistent improvements in cardiovascular risk factors, health behaviours and medication adherence. Whether those gains persist is still unclear.

    ⚠What it shows: Encouraging but unsettled: the authors gathered 18 trials in which people were assigned at random, plus single-arm studies and pooled analyses, then read across them rather than combining the numbers formally. They are open that nobody has established the right dose, that the populations studied were not diverse, and that longer-term outcomes beyond the usual 6 to 12 weeks remain uncertain.Review · Cardiol Clin

    Full breakdown →Breathwork for Recovery and Stress →Heart Age Calculator →Positive Psychology Interventions and Cardiovascular Health: Frequency and Duration to Sustain Cardiovascular Benefits. Cardiol Clin 2026
20. Mindpreliminary · human dataAdded 2 September 2026

    High-intensity intervals left anxiety and low mood unchanged in healthy adults

    Pooled results from eight randomised trials in 471 healthy participants, 81% of them female, found high-intensity interval training produced no significant reduction in anxiety or depressive symptoms compared with a non-exercising control group. The reviewers rate the certainty of that evidence as very low.

    ⚠What it shows: A real null, but a thin one: results pooled from only eight trials with 471 healthy participants, and the reviewers themselves call the certainty very low. Everyone involved was already healthy, so this says nothing about people living with diagnosed depression or anxiety.Meta-analysis · Scand J Med Sci Sports

    Full breakdown →HIIT explained →Heart Rate Zone Calculator →Effects of high-intensity interval training on depressive and anxiety symptoms in healthy individuals: A systematic review and meta-analysis of randomized clinical trials. Scand J Med Sci Sports 2024
21. Mindwell supported · human dataAdded 31 August 2026

    Smoking and inactivity dominate dementia risk; caffeine's case stays thin

    A systematic review of 247 studies with pooled results from 31 studies of new Alzheimer's cases linked low educational attainment (risk ratio 1.99), high homocysteine (1.93) and current or ever smoking (1.37) to higher risk, while higher physical activity and n-3 fatty acids appeared protective. The share of cases attributable to the factor was highest for physical activity (31.9%) and smoking (31.09%), whereas caffeine had the least consistent findings of all the factors reviewed.

    ⚠What it shows: Broad and fairly consistent, but built on studies that followed people rather than testing changes on them: 247 studies reviewed and 31 pooled for new Alzheimer's cases. People who exercise more or study longer differ in many other ways, so the share-of-cases figures are best read as ceilings rather than promises.Meta-analysis · BMC Public Health

    Full breakdown →Executive function explained →Healthy Lifestyle & Life Expectancy →Epidemiologic studies of modifiable factors associated with cognition and dementia: systematic review and meta-analysis. BMC Public Health 2014
22. Mindwell supported · human dataAdded 30 August 2026

    People with depression drop out of exercise less often than control groups

    Across 40 randomised trials covering 1720 people with depression, 18.1% dropped out of exercise programmes, and dropout was lower in the exercise groups than in control conditions. Supervision by physiotherapists or exercise physiologists predicted fewer dropouts, while more severe baseline symptoms predicted more.

    ⚠What it shows: Solid ground for the tolerability claim: results pooled from 40 trials in 1720 people with depression. It measures who kept turning up in trials rather than how well exercise treats depression, and people who volunteer for a trial may already be keener than average.Meta-analysis · J Affect Disord

    Full breakdown →Dropout from exercise randomized controlled trials among people with depression: A meta-analysis and meta regression. J Affect Disord 2016
23. Mindpreliminary · human dataAdded 30 August 2026

    Depression and smoking raise back pain risk, and back pain returns the favour

    A bidirectional Mendelian randomisation study using genetic data found evidence that greater education (odds ratio 0.54 per 4.2 years of schooling), ever smoking (1.27), greater alcohol consumption (1.29 per category increase) and major depressive disorder (1.41) causally increase the risk of chronic back pain. In the reverse direction, chronic back pain increased alcohol consumption (1.19) and smoking (1.21), while physical activity and sleep did not meet the study's criteria for a causal link.

    ⚠What it shows: Stronger than a simple correlation, weaker than a trial: this method uses inherited genetic differences as stand-ins for lifestyle exposures, which sidesteps some confounding but rests on assumptions that can fail. The genetic data came from people of European ancestry, so it may not carry over to other populations.Meta-analysis · Eur Spine J

    Full breakdown →Back Pain →Causal effects of psychosocial factors on chronic back pain: a bidirectional Mendelian randomisation study. Eur Spine J 2022
24. Mindwell supported · human dataAdded 29 August 2026

    Exercise and meditation eased student depression about equally

    Across 44 trials, aerobic exercise, traditional Chinese exercises and meditation each produced moderate reductions in college students' depressive symptoms, with broadly similar effects across the three approaches.

    ⚠What it shows: Reasonably solid on the broad conclusion: results pooled from 44 trials all pointed the same way, but the individual studies disagreed with each other a lot, so the true size of the benefit is uncertain. Every participant was a college student, so older adults may respond differently.Meta-analysis · Medicine (Baltimore)

    Full breakdown →Effects of aerobic exercise, traditional Chinese exercises, and meditation on depressive symptoms of college student: A meta-analysis of randomized controlled trials. Medicine (Baltimore) 2021

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