Metabolic & Cardiometabolic
genetic heritability of brain diseases is a low
In plain terms: Is the genetic heritability of brain diseases low, leaving a large lifestyle role?
Mostly not — this holds only for depression (~30-40% heritable). Schizophrenia, bipolar disorder and Alzheimer's are highly heritable (60-80%), so a blanket 'brain disease heritability is low' overgeneralises from his depression/twin work.
📅 Last reviewed: 2026-07-14 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: All trials, pooled (Meta-analysis)
How the studies fall
What the evidence shows
This holds only for depression, at roughly 30 to 40 percent. Schizophrenia, bipolar disorder and affective illness are substantially heritable — a Swedish twin study put liability heritability at 64 to 83 percent — and across 2,748 twin studies mean heritability was 49 percent, with psychiatric traits above that. Heritability also rises with age, so the figure depends on when it is measured.
The evidence (14)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Bergen SE, Gardner CO, Kendler KS 2007 · Twin Res Hum Genet | meta-analysis | mixed | moderate | Meta-analysis found heritability of depressive and anxiety symptoms rises across adolescence, i.e. moderate and age-dependent rather than uniformly low. |
| Liu S, Bush WS, Akinyemi RO, Byrd GS, Caban-Holt AM, Rajabli F, Reitz C, Kunkle BW, Tosto G, Vance JM, Pericak-Vance M, Haines JL, Williams SM, Crawford DC 2025 · PLoS Genet | observational | contradicts | moderate | Systematic review found late-onset Alzheimer heritability estimates from twin/GWAS studies are often high, undercutting a uniformly low-heritability claim. |
| Polderman TJ, Benyamin B, de Leeuw CA, Sullivan PF, van Bochoven A, Visscher PM, Posthuma D 2015 · Nat Genet | meta-analysis | mixed | high | Meta-analysis of 2,748 twin studies found mean heritability of 49% across traits, with psychiatric/neurological domains among the more heritable. |
| Kendler KS, Pedersen NL, Neale MC, Mathé AA 1995 · Psychol Med | observational | contradicts | moderate | Swedish twin study found affective illness highly heritable, with liability heritability of 64-83%. |
| Hu Y, Gruen JR, Zhang H 2026 · Proceedings of the National Academy of Sciences of the United States of America | observational | supports | moderate | In a UK Biobank depression study, stratified SNP-based heritability was higher among childhood-trauma-exposed individuals (13.3%) versus unexposed (6.0%), both markedly low. |
| Dattani S, Sham PC, Jermy BS, Coleman JRI, Howard DM, Lewis CM 2023 · Transl Psychiatry | observational | mixed | moderate | Study addresses the gap between low SNP-heritability and higher twin-heritability estimates for depression, bipolar, and schizophrenia. |
| Cholerton B, Godrich D, Pasteris J, Rivero J, Martin ER, Kunkle BW, Naj AC, Hamilton-Nelson KL, Wang H, Lee WP, Dumitrescu L, Hohman TJ, Mayeux R, Larson EB, Crane PK, Keene CD, Latimer CS, Mukherjee S, Kofler JK, Kamboh MI, Bennett DA, Molina-Porcel L, Cuccaro M, Pericak-Vance MA, Rundek T, Scott WK, Kukull W, Schellenberg G, Alzheimer’s Disease Genetics Consortium, Beecham GW, Montine TJ 2026 · PLoS genetics | observational | mixed | moderate | GWAS meta-analysis of Alzheimer's/ADRD neuropathologic lesions found heritability high for amyloid plaques (78%) and intermediate for TDP-43 inclusions (41%), but low for remaining AD/ADRD pathologic features. |
| Wray NR, Gottesman II 2012 · Front Genet | observational | contradicts | high | National-registry estimates were high for schizophrenia (0.67) and bipolar (0.62) but low-moderate for major depression (0.32). |
| Song J, Pasman JA, Johansson V, Kuja-Halkola R, Harder A, Karlsson R, Lu Y, Kowalec K, Pedersen NL, Cannon TD, Hultman CM, Sullivan PF 2024 · JAMA Psychiatry | observational | contradicts | high | Twin study confirms schizophrenia and bipolar disorder are highly heritable psychiatric disorders. |
| Sullivan PF, Neale MC, Kendler KS 2000 · Am J Psychiatry | meta-analysis | supports | high | Meta-analysis estimated major depression heritability at only about 37%, leaving a large individual-environment contribution. |
| Holen B, Rahman Z, Shadrin AA, Icick R, O'Connell KS, Rødevand L, Parker N, Tesfaye M, Jaholkowski P, Frei O, Dale AM, Djurovic S, Andreassen OA, Smeland OB 2026 · General psychiatry | observational | mixed | moderate | Genome-wide mixed-methods study of substance use disorders found SNP-based heritability of 0.10 for alcohol use disorder, 0.10 for opioid use disorder, and 0.01 for cannabis use disorder. |
| Rousset RZ, den Braber A, Verberk IMW, Boonkamp L, Wilson DH, Ligthart L, Teunissen CE, de Geus EJC 2025 · Alzheimers Dement | observational | contradicts | moderate | Nuclear-twin-family study describes Alzheimer's disease as highly heritable (60-80%). |
| Dijkstra JIR, Hulsman M, Waterink L, Holstege H, Teunissen CE, Christiaansen WFL, de Jong BA, Kochunov P, Donohue B, Zwan MD, den Braber A, Vermunt L, van der Lee SJ 2025 · NPJ dementia | observational | contradicts | moderate | Family-based heritability study of nine brain diseases found Alzheimer's disease h2=73%, ALS h2=72%, Parkinson's disease h2=38%, frontotemporal dementia h2=48%, vascular dementia h2=41%; only multiple sclerosis was low (h2=10%). |
| Hosang GM, Martin J, Karlsson R, Lundström S, Larsson H, Ronald A, Lichtenstein P, Taylor MJ 2022 · JAMA Psychiatry | observational | contradicts | moderate | Twin study found a substantial genetic contribution to bipolar-spectrum symptoms and severe mental illnesses. |
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