Diets
ketogenic diet decreases major depression and anxiety symptoms
In plain terms: Does a ketogenic diet reduce depression or anxiety?
Contested Diets 🔬 Includes disconfirming
Part of: 🥗 ketogenic diet
RefutedContestedStrong support
consensus score 0.08
The best-controlled trial and a 2026 meta-analysis find the therapeutic value uncertain and no clear advantage over comparator diets, so the claim is not yet supported.
📅 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: Human trials (RCT / n-of-1)
MechanismIn-vitroAnimalObservationalRCTMeta-analysis
How the studies fall
5 support 1 contradict 2 tested null 10 mixed · 18 sources, 6 independent groups
What the evidence shows
The best-controlled trial and a 2026 meta-analysis leave the therapeutic value uncertain, with no clear antidepressant effect. What supports the claim is case reports and small uncontrolled cohorts, including a single-patient retrospective and an online group programme in nineteen people, which is the weakest design for a condition with large placebo responses.
The evidence (18)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Laurent N 2026 · Frontiers in nutrition | n-of-1 | supports | low | Single retrospective case report (n=1) of 25-week KMT in treatment-resistant PTSD; PCL-5 32->2, PHQ-9 10->0, GAD-7 6->0, with DASS-42 confirming resolution of depressive/anxious/stress symptoms. |
| Bellamy EL 2026 · Frontiers in nutrition | observational | supports | low | Retrospective, uncontrolled evaluation of online group KMT (n=19) with baseline PHQ-9/GAD-7 >4; PHQ-9 fell 13->5 (62% reduction) and GAD-7 fell 13->7 (46% reduction) over 12 weeks, most reaching clinically meaningful improvement. |
| Gao M, Kirk M, Knight H, Lash E, Michalopoulou M, Guess N, Stevens R, Browning M, Weich S, Burnet PWJ, Jebb SA, Aveyard P 2026 · JAMA Psychiatry | RCT | mixed | moderate | First well-controlled RCT in treatment-resistant depression — designed because RCT evidence was lacking; no clear efficacy signal, adherence poor. |
| Carneiro RAVD, Cardoso RM, Lunardi MDS, Lima MC, Anzani S, Darella AX, Salvador MT, de Paula Moraes T, Sostizzo NC, Venske DK, Moreira JD, Ribeiro LC, Borgatto AF, Lin K 2026 · Epilepsia | observational | mixed | low | Single-center prospective cohort (n=17) of modified Atkins diet in adult drug-resistant epilepsy over up to 12 months; anxiety (HADS-A) improved significantly (-4.38, p=.01) independent of seizure changes, though depression (HADS-D) not rep |
| Filippi F, Lorenzut S, Garbo R, Lamon E, Del Negro I, Nilo A, Pez S, Gigli GL, Valente M 2026 · Nutrients | observational | mixed | low | Single-arm open-label study (n=16 MS patients) on 3-month KD; DASS-21 depression subscale improved (3.18 vs 6.15, p=0.036) and anxiety subscale improved (5.15 vs 1.55, p=0.019) from baseline to 3 months. |
| Janssen-Aguilar R, la Portilla JG, Martínez-Juárez IE, Mimiaga-Hernandez C, Alvarado-Luis G, Aguilar-Hernandez A, Garcia-Esparza KA, Hernadez-Palestina M, Crail-Meléndez D 2025 · Epilepsia Open | RCT | mixed | low | Small feasibility RCT found modified Atkins (ketogenic) diet reduced depression and anxiety at 6 weeks without significant between-group difference vs control diet. |
| Laurent N, Bellamy EL, Hristova D, Houston A 2025 · Frontiers in nutrition | n-of-1 | supports | low | Single retrospective case study (n=1) of KMT (1.5:1 ratio) with multidisciplinary support in a 47-year-old woman with lifelong treatment-resistant MDD; PHQ-9 25->0 and GAD-7 3->0 by 2-4 months, full remission achieved. |
| Decker DD, Patel R, Cheavens J, Hayes SM, Whitted W, Lee AJ, Buga A, Robinson BT, Crabtree CD, Kackley ML, Stoner JT, Sapper TN, Chebbi A, Volek JS 2025 · Translational psychiatry | observational | supports | low | 10-12 week single-arm pilot (n=16 completers) of well-formulated KD as adjunct in college students with MDD; PHQ-9 fell 69% and HRSD fell 71% (both p<0.001), with improvement starting 2-6 weeks in. |
| Frank GKW, Scolnick B, Beckwith C, Shott ME, Kilty S, Swindle S, Lutter M, Rho JM 2026 · Communications medicine | observational | mixed | low | Uncontrolled single-arm feasibility trial (n=22, 18 completed) of 14-week weight-maintaining KD in adults with anorexia nervosa. Depression scores decreased over time alongside EDE-Q subscales (MANCOVA p<0.001); 72% within normal range for |
| P Rigby B, Needham N, Grossi H, Kamenska I, H Campbell I, Meadowcroft B, Creasy F, Fisher C, Bahuguna P, Norrie J, Thompson G, C Gibbs M, Mitchell-Grigorjeva M, McLellan A, Moses T, Burgess K, Brown R, J Thrippleton M, Campbell H, J Smith D, A Simpson S 2025 · BMC Psychiatry | observational | mixed | low | Process evaluation of a bipolar ketogenic-diet pilot found feasibility and some symptom benefit but high burden/attrition. |
| Liang Y, Taylor A, Haas V, Qiu C 2026 · Eating and weight disorders : EWD | observational | mixed | low | 12-week single-arm pilot (n=20 completers, BED patients) of dietitian-supported KD; PHQ-9 depression scores fell from 16.5 to 8.2 (p=0.005) alongside binge-eating improvement. |
| Janssen-Aguilar R, Vije T, Peera M, Al-Shamali HF, Meshkat S, Lin Q, Lou W, Laviada-Molina H, Phillips ML, Bhat V 2026 · JAMA Psychiatry | meta-analysis | tested-null | high | Systematic review/meta-analysis: therapeutic value of KD in psychiatric populations remains uncertain; evidence weak/heterogeneous. |
| Bellamy EL, Hadjiefthyvoulou F, Walsh J, Brown J, Turner J 2024 · Front Nutr | observational | supports | low | Qualitative thematic analysis reported participants experienced improved well-being and reduced depressive symptoms on a ketogenic diet. |
| Mela V, Ortiz Samur NS, Vijaya AK, Gálvez VJ, García-Martín ML, Bandera B, Martínez-Montoro JI, Gómez-Pérez AM, Moreno-Indias I, Tinahones FJ 2026 · Brain Behav Immun | RCT | contradicts | moderate | Pilot RCT: keto LESS effective than Mediterranean diet at reducing depression/anxiety in obesity. |
| Campbell IH, Needham N, Grossi H, Kamenska I, Luz S, Sheehan S, Thompson G, Thrippleton MJ, Gibbs MC, Leitao J, Moses T, Burgess K, Rigby BP, Simpson SA, McIntosh E, Brown R, Meadowcroft B, Creasy F, Mitchell-Grigorjeva M, Norrie J, McLellan A, Fisher C, Zieliński T, Gaggioni G, Campbell H, Smith DJ 2025 · BJPsych Open | observational | mixed | low | Uncontrolled pilot of ketogenic diet in bipolar disorder reported improvements in mood/psychiatric and metabolic measures. |
| Varaee H, Darand M, Hassanizadeh S, Hosseinzadeh M 2023 · J Affective Disorders | meta-analysis | tested-null | moderate | Meta-analysis of low-carb diets: no significant overall effect on depression/anxiety. |
| Brietzke E, Fabe J, Bambokian A, Breda V, Chaves C, Shelp J, Terpstra A, Koning E, Groll D, Milev R, McIntyre RS, Mansur RB, Soares CN, Gomes FA 2026 · J Affective Disorders | observational | mixed | low | Uncontrolled pilot of supervised KD in moderate-severe depression: feasible, preliminary signal only. |
| Gao M, Kirk M, Lash E, Knight H, Michalopoulou M, Guess N, Browning M, Weich S, Burnet P, Jebb SA, Stevens R, Aveyard P 2024 · J Psychiatr Res | mechanism | mixed | moderate | Protocol/rationale paper for a treatment-resistant-depression ketogenic RCT summarizing preclinical/mechanistic basis; not itself outcome evidence. |
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