The Healthspan Map · Neurological & Mental Health

Depression / low mood

Named for Depression / low mood

Evidence naming Depression / low mood directly — 61 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Nutrient or leverDirectionStrengthEvidence typeWhat was foundSource
Cardio (moderate + intervals)Do thisStrongRCT / meta-analysisAerobic exercise has a large antidepressant effect (SMD ~-0.8 to -1.6); guideline-recognized for depression.Banyard et al. 2025; exercise umbrella reviews (opens in a new tab)
Cardio (moderate + intervals)Do thisStrongRCT / meta-analysisAerobic exercise has a large antidepressant effect (SMD ~-0.8 to -1.6); guideline-recognized for depression.Aerobic exercise for adult patients with major depressive disorder in mental health services: A systematic review and meta-analysis, Depress Anxiety 2019 (opens in a new tab)
EPA/DHA (omega-3)Eat enough ofStrongRCT / meta-analysisOmega-3 (EPA-predominant, 1-2 g/d) significantly reduces depressive symptoms (SMD -0.28) across 26 RCTs.Bai et al. 2019, Transl Psychiatry (opens in a new tab)
Falling & staying asleepWatch thisStrongRCT / meta-analysisInsomnia roughly doubles the risk of developing depression (OR 2.60); a core modifiable risk factor.Baglioni et al. 2011 (opens in a new tab)
Loneliness — reduceWatch thisStrongRCT / meta-analysisLoneliness is moderately-to-strongly associated with depression (r~0.49); social connection is protective.Gabarrell-Pascuet et al. 2023 (opens in a new tab)
Strength (resistance)Do thisStrongRCT / meta-analysisResistance training significantly reduces depressive symptoms (SMD ~-0.9), independent of aerobic exercise.Resistance-training-for-depression meta-analysis (cf. Gordon 2018) (opens in a new tab)
Tobacco / vaping — quitDo thisStrongRCT / meta-analysisQuitting smoking reduces depression (SMD -0.25); guideline bodies establish smoking as harmful to mental health.Taylor et al. 2014, BMJ (opens in a new tab)
Tobacco / vaping — quitDo thisStrongRCT / meta-analysisQuitting smoking reduces depression (SMD -0.25); guideline bodies establish smoking as harmful to mental health.Change in mental health after smoking cessation: systematic review and meta-analysis, BMJ 2014 (opens in a new tab)
Added SugarsDon't overdoModerateRCT / meta-analysisHigh added-sugar/ultra-processed intake is associated with greater depression risk (OR 1.44; HR 1.22).Lane et al. 2022 (opens in a new tab)
Alcohol — cut backDo thisModerateRCT / meta-analysisAlcohol disrupts stress-axis regulation and is strongly comorbid with and worsens depression.Weckesser et al. 2025; alcohol-depression comorbidity (opens in a new tab)
Alcohol — cut backDo thisModerateRCT / meta-analysisAlcohol disrupts stress-axis regulation and is strongly comorbid with and worsens depression.Weckesser et al., "A systematic review with meta-analysis on the relation between acute stress, alcohol consumption and cortisol", Transl Psychiatry 2025 (opens in a new tab)
Belonging (groups / third place)Watch thisModerateRCT / meta-analysisLoneliness is moderately-to-strongly associated with depression (r~0.49); social connection is protective.Gabarrell-Pascuet et al. 2023 (opens in a new tab)
Biotin (B7)Eat enough ofModerateEstablished clinicalAdult deficiency causes neurological findings including depression, lethargy and hallucinations.NIH ODS – Biotin (opens in a new tab)
Breath/mind (slow breathing)Do thisModerateSystematic reviewSlow breathing and mind-body practice ease depressive symptoms via autonomic and stress-axis pathways.Slow-breathing / mind-body reviews (opens in a new tab)
Breath/mind (slow breathing)Do thisModerateRCT / meta-analysisSlow breathing and mind-body practice ease depressive symptoms via autonomic and stress-axis pathways."Effects of voluntary slow breathing on heart rate and heart rate variability: a systematic review and meta-analysis", Neurosci Biobehav Rev 2022 (opens in a new tab)
Calm rest spaceDo thisModerateRCT / meta-analysisGreenspace/nature exposure is associated with lower depression and stress-hormone levels.Twohig-Bennett & Jones 2018 (opens in a new tab)
Daily movement baselineDo thisModerateRCT / meta-analysisAerobic exercise has a large antidepressant effect (SMD ~-0.8 to -1.6); guideline-recognized for depression.Banyard et al. 2025; exercise umbrella reviews (opens in a new tab)
Daily movement baselineDo thisModerateRCT / meta-analysisAerobic exercise has a large antidepressant effect (SMD ~-0.8 to -1.6); guideline-recognized for depression.Banyard et al., "Effect of exercise on depression and anxiety symptoms: systematic umbrella review with meta-analysis", Br J Sports Med 2026 (opens in a new tab)
Flexibility (stretching)Do thisModerateRCT / meta-analysisAerobic exercise has a large antidepressant effect (SMD ~-0.8 to -1.6); guideline-recognized for depression.Banyard et al. 2025; exercise umbrella reviews (opens in a new tab)
Flexibility (stretching)Do thisModerateRCT / meta-analysisAerobic exercise has a large antidepressant effect (SMD ~-0.8 to -1.6); guideline-recognized for depression.Banyard et al., "Effect of exercise on depression and anxiety symptoms: systematic umbrella review with meta-analysis", Br J Sports Med 2026 (opens in a new tab)
Folate (B9)Eat enough ofModerateEstablished clinicalDeficiency causes neuropsychiatric symptoms including depression and cognitive impairment.StatPearls – Folate (opens in a new tab)
Inner circle (close ties)Watch thisModerateRCT / meta-analysisLoneliness is moderately-to-strongly associated with depression (r~0.49); social connection is protective.Gabarrell-Pascuet et al. 2023 (opens in a new tab)
IodineEat enough ofModerateEstablished clinicalHypothyroidism from deficiency causes depression and low mood.NIH ODS – Iodine (opens in a new tab)
IronEat enough ofModerateCohort / observationalIron deficiency is linked to low mood, anxiety and anhedonia and is sometimes misdiagnosed as depression; symptoms improve with repletion.Psychiatric-IDA review (PMC10595923) (opens in a new tab)
MagnesiumEat enough ofModerateCohort / observationalLow magnesium status is associated with depression.NIH ODS – Magnesium (opens in a new tab)
Morning daylightDo thisModerateRCT / meta-analysisBright/morning light is first-line for seasonal depression; mild-to-moderate, mixed evidence for non-seasonal MDD.Light-therapy-for-depression meta-analysis (Do et al. 2022) (opens in a new tab)
Niacin (B3)Eat enough ofModerateEstablished clinicalNiacin deficiency causes neuropsychiatric symptoms including depression and apathy.Pellagra case literature (opens in a new tab)
Polyunsaturated fatEat enough ofModerateCohort / observationalLow omega-3 PUFA status is linked to depression and impaired cognition; PUFAs are central to brain structure and anti-inflammatory signaling.Omega-3 / mood literature (opens in a new tab)
Polyunsaturated fatEat enough ofModerateRCT / meta-analysisLow omega-3 PUFA status is linked to depression and impaired cognition; PUFAs are central to brain structure and anti-inflammatory signaling."Omega-3 polyunsaturated fatty acids in treating depression: a meta-analysis", J Affect Disord 2025 (opens in a new tab)
Screens before bed — cut backDo thisModerateRCT / meta-analysisProblematic smartphone use is associated with markedly higher depression (OR 3.17).Sohn et al. 2019, BMC Psychiatry (opens in a new tab)
SeleniumDon't overdoModerateReview / narrativeSelenium overexposure (selenosis) causes a neuropsychological syndrome including depression, irritability and fatigue.Vinceti et al. 2013; NIH ODS (opens in a new tab)
SeleniumDon't overdoModerateEstablished clinicalSelenium overexposure (selenosis) causes a neuropsychological syndrome including depression, irritability and fatigue.NIH Office of Dietary Supplements — Selenium (opens in a new tab)
Sleep durationWatch thisModerateRCT / meta-analysisInsomnia roughly doubles the risk of developing depression (OR 2.60); a core modifiable risk factor.Baglioni et al. 2011 (opens in a new tab)
Sleep hygiene - Wind-downDo thisModerateRCT / meta-analysisInsomnia roughly doubles the risk of developing depression (OR 2.60); a core modifiable risk factor.Baglioni et al. 2011 (opens in a new tab)
Sleep quality (refreshed)Watch thisModerateRCT / meta-analysisInsomnia roughly doubles the risk of developing depression (OR 2.60); a core modifiable risk factor.Baglioni et al. 2011 (opens in a new tab)
Sleep regularityWatch thisModerateRCT / meta-analysisInsomnia roughly doubles the risk of developing depression (OR 2.60); a core modifiable risk factor.Baglioni et al. 2011 (opens in a new tab)
Staying in touch (social reps)Do thisModerateRCT / meta-analysisLoneliness is moderately-to-strongly associated with depression (r~0.49); social connection is protective.Gabarrell-Pascuet et al. 2023 (opens in a new tab)
Sugary drinks & snacks — cut backDo thisModerateRCT / meta-analysisHigher ultra-processed intake is associated with greater depression risk (OR 1.44; prospective HR 1.22).Lane et al. 2022 (opens in a new tab)
Total FiberEat enough ofModerateCohort / observationalHigher dietary fiber shows a robust L-shaped inverse link with depression (up to ~30% lower odds); acts via the gut-brain axis and lower inflammation.Dietary fiber & depression (NHANES 2005-2020) (opens in a new tab)
Toxic relationships — reduceWatch thisModerateRCT / meta-analysisLoneliness is moderately-to-strongly associated with depression (r~0.49); social connection is protective.Gabarrell-Pascuet et al. 2023 (opens in a new tab)
Ultra-processed food — cut backDo thisModerateRCT / meta-analysisHigher ultra-processed intake is associated with greater depression risk (OR 1.44; prospective HR 1.22).Lane et al. 2022 (opens in a new tab)
Vitamin B12Eat enough ofModerateEstablished clinicalDeficiency causes depression, irritability and, rarely, psychosis.NIH ODS – Vitamin B12 (opens in a new tab)
Vitamin B6Eat enough ofModerateMechanisticB6 (as PLP) is a cofactor for serotonin, dopamine and GABA synthesis; deficiency causes depression, confusion and irritability.NIH ODS / systematic review – Vitamin B6 (opens in a new tab)
Vitamin B6Eat enough ofModerateEstablished clinicalB6 (as PLP) is a cofactor for serotonin, dopamine and GABA synthesis; deficiency causes depression, confusion and irritability.NIH Office of Dietary Supplements — Vitamin B6 (opens in a new tab)
Vitamin CEat enough ofModerateEstablished clinicalDepression is a recognized feature of scurvy.NIH ODS – Vitamin C (opens in a new tab)
Vitamin DEat enough ofModerateRCT / meta-analysisEach 1000 IU/day vitamin D3 slightly reduces depressive symptoms (SMD -0.32); benefit greater in those with depression/deficiency.Vitamin D & depression dose-response meta 2024 (opens in a new tab)
Warmth & quality of tiesWatch thisModerateRCT / meta-analysisLoneliness is moderately-to-strongly associated with depression (r~0.49); social connection is protective.Gabarrell-Pascuet et al. 2023 (opens in a new tab)
ZincEat enough ofModerateRCT / meta-analysisDepression is associated with lower serum zinc; zinc supplementation reduces depressive symptoms (SMD -0.36).Swardfager et al. 2013; zinc supplementation meta 2021 (opens in a new tab)
ZincEat enough ofModerateRCT / meta-analysisDepression is associated with lower serum zinc; zinc supplementation reduces depressive symptoms (SMD -0.36).Swardfager et al., "Zinc in depression: a meta-analysis", Biol Psychiatry 2013 (opens in a new tab)
Anchor foodsWatch thisEmergingRCT / meta-analysisHigher ultra-processed intake is associated with greater depression risk (OR 1.44; prospective HR 1.22).Lane et al. 2022 (opens in a new tab)
Colours a dayWatch thisEmergingRCT / meta-analysisHigher ultra-processed intake is associated with greater depression risk (OR 1.44; prospective HR 1.22).Lane et al. 2022 (opens in a new tab)
Cook real foodDo thisEmergingRCT / meta-analysisHigher ultra-processed intake is associated with greater depression risk (OR 1.44; prospective HR 1.22).Lane et al. 2022 (opens in a new tab)
Daytime alertnessWatch thisEmergingRCT / meta-analysisInsomnia roughly doubles the risk of developing depression (OR 2.60); a core modifiable risk factor.Baglioni et al. 2011 (opens in a new tab)
ManganeseDon't overdoEmergingEstablished clinicalManganism includes behavioral/psychiatric changes — apathy, anorexia and irritability.Manganism literature (opens in a new tab)
Movement (breaking up sitting)Do thisEmergingRCT / meta-analysisAerobic exercise has a large antidepressant effect (SMD ~-0.8 to -1.6); guideline-recognized for depression.Banyard et al. 2025; exercise umbrella reviews (opens in a new tab)
Movement (breaking up sitting)Do thisEmergingRCT / meta-analysisAerobic exercise has a large antidepressant effect (SMD ~-0.8 to -1.6); guideline-recognized for depression.Banyard et al., "Effect of exercise on depression and anxiety symptoms: systematic umbrella review with meta-analysis", Br J Sports Med 2026 (opens in a new tab)
SeleniumEat enough ofEmergingReview / narrativeLow selenium status is inversely associated with low mood/depression (U-shaped risk); evidence emerging.Trace-minerals & mood review 2023 (opens in a new tab)
Sleep hygiene - BedroomDo thisEmergingRCT / meta-analysisInsomnia roughly doubles the risk of developing depression (OR 2.60); a core modifiable risk factor.Baglioni et al. 2011 (opens in a new tab)
Sleep hygiene - Clock & lightDo thisEmergingRCT / meta-analysisInsomnia roughly doubles the risk of developing depression (OR 2.60); a core modifiable risk factor.Baglioni et al. 2011 (opens in a new tab)
Sleep hygiene - Intake & timingDo thisEmergingRCT / meta-analysisInsomnia roughly doubles the risk of developing depression (OR 2.60); a core modifiable risk factor.Baglioni et al. 2011 (opens in a new tab)
Water / hydrationDo thisEmergingRCT / meta-analysisHigher ultra-processed intake is associated with greater depression risk (OR 1.44; prospective HR 1.22).Lane et al. 2022 (opens in a new tab)

Held for the whole Neurological & Mental Health system

These rows name no single condition. The Map records them against the whole body system, so they are shown separately rather than folded in.

Evidence held for the Neurological & Mental Health system — 28 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Nutrient or leverDirectionStrengthEvidence typeWhat was foundSource
Falling & staying asleepWatch thisStrongRCT / meta-analysisInsomnia roughly doubles the longitudinal risk of developing depression.Baglioni et al., J Affect Disord 2011 (insomnia as predictor of depression, meta-analysis) (opens in a new tab)
Loneliness — reduceWatch thisStrongEstablished clinicalSocial isolation and loneliness are modifiable risk factors for dementia; social interventions can slow cognitive decline.Social isolation and dementia review (2025) (opens in a new tab)
ManganeseDon't overdoStrongEstablished clinicalManganese excess accumulates in the basal ganglia and causes MANGANISM — a Parkinson-like extrapyramidal syndrome (bradykinesia, rigidity, tremor, gait/speech changes). Chiefly from inhalation (welding/mining), contaminated water, or IV/parenteral nutrition and liver disease; the oral UL is 11 mg.NIH DRI / manganism literature (opens in a new tab)
ManganeseDon't overdoStrongRCT / meta-analysisManganese excess accumulates in the basal ganglia and causes MANGANISM — a Parkinson-like extrapyramidal syndrome (bradykinesia, rigidity, tremor, gait/speech changes). Chiefly from inhalation (welding/mining), contaminated water, or IV/parenteral nutrition and liver disease; the oral UL is 11 mg.Manganese exposure and cognitive performance: A meta-analytical approach, Environ Pollut 2023 (opens in a new tab)
SodiumEat enough ofStrongEstablished clinicalAcute severe hyponatremia causes cerebral edema, confusion, seizures, coma and can be lethal; it is the most common electrolyte disorder (usually from water excess/illness, not low salt intake).LPI / StatPearls – Hyponatremia (opens in a new tab)
SodiumEat enough ofStrongEstablished clinicalAcute severe hyponatremia causes cerebral edema, confusion, seizures, coma and can be lethal; it is the most common electrolyte disorder (usually from water excess/illness, not low salt intake).Linus Pauling Institute — Sodium (opens in a new tab)
WaterDon't overdoStrongEstablished clinicalOverhydration (drinking faster than the kidneys can excrete, ~0.8-1 L/hour) dilutes blood sodium -> hyponatremia/water intoxication: headache, nausea, confusion, seizures, cerebral edema, coma and death. Seen in endurance athletes and psychogenic polydipsia. (Directly connects to the Sodium deficiency row.)Water-intoxication systematic review (opens in a new tab)
Belonging (groups / third place)Watch thisModerateEstablished clinicalGroup engagement and community connection help preserve cognition and mental health.Social engagement and cognition review (2025) (opens in a new tab)
Breath (how you breathe)Watch thisModerateRCT / meta-analysisSlow breathing shifts autonomic balance toward parasympathetic activity, reducing stress and anxiety.Slow-paced breathing meta-analysis, Mindfulness 2024 (opens in a new tab)
CopperDon't overdoModerateEstablished clinicalCopper accumulation (Wilson's disease) causes neurological (tremor, dystonia, dysarthria) and psychiatric symptoms, plus Kayser-Fleischer eye rings.Wilson's disease literature (opens in a new tab)
Daytime alertnessWatch thisModerateEstablished clinicalExcessive sleepiness reduces mental processing, concentration and reaction time.Sleepiness and neurocognitive-function literature (opens in a new tab)
Inner circle (close ties)Watch thisModerateEstablished clinicalRich social ties protect mental and cognitive health; isolation raises dementia risk.Social engagement and cognition review (2025) (opens in a new tab)
MagnesiumDon't overdoModerateEstablished clinicalHypermagnesemia causes lethargy, muscle weakness, difficulty breathing and depression.NIH ODS – Magnesium (opens in a new tab)
MolybdenumEat enough ofModerateEstablished clinicalDietary deficiency is essentially unreported; the genetic molybdenum cofactor deficiency (MoCD) causes neonatal seizures, severe brain degeneration and early death. One TPN case caused headache, tachycardia and night blindness.MoCD literature / NIH ODS – Molybdenum (opens in a new tab)
MolybdenumEat enough ofModerateEstablished clinicalDietary deficiency is essentially unreported; the genetic molybdenum cofactor deficiency (MoCD) causes neonatal seizures, severe brain degeneration and early death. One TPN case caused headache, tachycardia and night blindness.NIH Office of Dietary Supplements — Molybdenum (opens in a new tab)
Screens before bed — cut backDo thisModerateRCT / meta-analysisProblematic smartphone use is linked to poorer mental health - higher stress, anxiety and depression.Yang et al., Psychiatry Research 2020 (meta-analysis) (opens in a new tab)
Sleep durationWatch thisModerateEstablished clinicalInsufficient sleep impairs cognition and mood regulation.Sleep-cognition/mood literature (AHA statement) (opens in a new tab)
Sleep quality (refreshed)Watch thisModerateRCT / meta-analysisPoor sleep quality raises risk of depression, anxiety and cognitive dysfunction.Sleep-quality and mental-health meta-analyses (opens in a new tab)
Staying in touch (social reps)Do thisModerateEstablished clinicalOngoing social engagement helps protect cognitive function.Social engagement and cognition review (2025) (opens in a new tab)
Vitamin EDon't overdoModerateRCT / meta-analysisTwo trials found increased hemorrhagic (brain) stroke risk with alpha-tocopherol supplements.NIH ODS – Vitamin E (ATBC; Physicians' Health Study) (opens in a new tab)
Warmth & quality of tiesWatch thisModerateCohort / observationalRelationship quality predicted cognitive health; secure attachment predicted better memory years later.Harvard Study of Adult Development (opens in a new tab)
Alcohol — cut backDo thisEmergingEstablished clinicalAlcohol contributes to alcohol-use disorders, epilepsy and other mental-health and neurological harms.Global Burden of Disease Alcohol Collaborators, Lancet 2018 (opens in a new tab)
Balance (one-leg stand)Watch thisEmergingEstablished clinicalSingle-leg balance is impaired by neurological conditions (Parkinson's, MS, dementia), reflecting central postural control.Single Leg Stance Test (clinical review) (opens in a new tab)
Blood oxygen (SpO2)Watch thisEmergingEstablished clinicalHypoxemia reduces oxygen delivery to the brain, causing confusion and, if chronic, cognitive impairment.Hypoxemia literature (opens in a new tab)
Blood pressureWatch thisEmergingRCT / meta-analysisHigh blood pressure is the leading risk factor for stroke and is linked to vascular cognitive decline.Prospective Studies Collaboration / hypertension literature (opens in a new tab)
Breathing rateWatch thisEmergingEstablished clinicalRespiratory rate is often the first vital sign to change with a shift in cardiac or neurological state.Vital-signs assessment guide (opens in a new tab)
Cardio / VO2maxWatch thisEmergingCohort / observationalLow CRF is associated with higher risk of dementia and depression across cohort meta-analyses.Lang et al., BJSM 2024 (opens in a new tab)
Sleep regularityWatch thisEmergingCohort / observationalIrregular sleep patterns are associated with poorer cognitive and academic performance.Circadian-disruption / performance literature (opens in a new tab)