Does a vegan diet cause depression?

The objection

“Meta-analyses keep finding more depression among vegetarians than meat-eaters, and one found that the more rigorous the study, the clearer the link. Meat supplies the B12 and omega-3 fats the brain needs, so cutting it out must affect your mood.”

The answer

People who avoid meat do report more depression in most meta-analyses, but nothing shows the diet causes it, and the newest studies that follow people over time find the link small or reversed. Of the nine reviews examined by a 2026 umbrella review, five were meta-analyses comparing people who avoid meat with meat-eaters: four found more depression among those avoiding meat on at least one measure, and one found no link [1]. The umbrella review judged the results conflicting, noted that nine in ten of the underlying studies were observational, and rated five of the nine reviews it examined as having several critical flaws in method [1]. Published after that review’s search closed in January 2025, a meta-analysis limited to studies that followed people over time (Luque-Martínez et al., 2025) found less depression among people who ate no meat (hazard ratio 0.74, 95% CI 0.59 to 0.89) [19]. Almost all of this evidence is about vegetarians, often with vegans folded in, and where Dobersek’s 2023 meta-analysis compared meat-eaters with vegans alone, it found more depression in vegans, a result only just clear of no difference (Hedges’ g 0.26, 95% CI 0.01 to 0.51) [4].

Are vegetarians and vegans more likely to be depressed?

Many studies find more depression among people who avoid meat, but the estimates vary widely and other studies find no difference, or less depression. The reviews, with their main results:

Review	What it pooled	What it found
Fazelian et al. (2022), meta-analysis	9 results on risk, 16 on scores	53% higher odds of depression in vegetarians (odds ratio 1.53, 95% CI 1.14 to 2.07), counting semi-vegetarian diets, which its authors called not robust: the link held in studies of semi-vegetarian diets (odds ratio 1.86, 95% CI 1.42 to 2.44) but not in lacto-ovo vegetarians, and there was no clear difference in average scores [2]
Ocklenburg and Borawski (2021), meta-analysis	13 studies, 49,889 people	Higher depression scores in vegetarians (standardised mean difference 0.19, 95% CI 0.06 to 0.31, as corrected in 2022) [3][1]
Dobersek et al. (2023), meta-analysis	20 studies, 171,802 people	Less depression in meat-eaters than in people who avoid meat (Hedges’ g 0.22, 95% CI 0.14 to 0.30) [4]
Iguacel et al. (2021), meta-analysis	13 studies, 17,809 people	No difference in depression scores, but higher odds in the 2 studies that classed people as depressed or not (odds ratio 2.14, 95% CI 1.11 to 4.15) [5][1]
Askari et al. (2022), meta-analysis	10 studies	No link (pooled estimate 1.02, 95% CI 0.84 to 1.25) [6]
Jain et al. (2022), systematic review without pooling	23 studies, 25 results	11 results showed more depression, 7 less and 7 no link [7]
Dobersek et al. (2021), systematic review without pooling	18 studies, 160,257 people	11 studies linked avoiding meat with poorer psychological health (depression, anxiety and related measures), 4 were equivocal and 3 favoured people who avoided meat [22]
Luque-Martínez et al. (2025), meta-analysis	20 cohort and case-control studies, none cross-sectional	Less depression among people who ate no meat (hazard ratio 0.74, 95% CI 0.59 to 0.89), also in the highest-quality studies; the link with merely eating less meat was inconsistent [19]

The two reviews of meat-free diets that the umbrella review found free of critical flaws, Iguacel’s and Jain’s, both found a mixed picture [1]. Several of the reviews pool vegans with vegetarians, and Ocklenburg and Borawski left vegan groups out wherever a study reported them alongside vegetarians [1].

Dobersek’s 2023 meta-analysis also reported that the more rigorous the study, the clearer the link [4]. The umbrella review counted this meta-analysis among the five with critical flaws [1], and the 2025 meta-analysis of studies that followed people over time found the opposite direction, including among its highest-quality studies [19]. Its authors flag the influence on that result of one study, of Buddhist volunteers in Taiwan where going without meat is well regarded, whose findings may not apply in societies that do not value meat-free diets [19]. The 2023 meta-analysis lists the US National Cattlemen’s Beef Association as a funder [4], and Dobersek’s 2021 systematic review did not report its funding or conflicts of interest, according to the umbrella review [1]. Yet in a 2025 commentary, Dobersek and two colleagues, two of whom declare past funding from the Beef Checkoff through the National Cattlemen’s Beef Association, concluded that on a nutritionally adequate diet, avoiding or eating meat and other animal foods will have no significant effect on mental health [8].

Does avoiding meat cause depression, or does depression come first?

No study has shown that avoiding meat causes depression, and in one national survey the depression tended to come first. In a representative sample of German adults drawn in 1997 (Michalak et al., 2012), 24.1% of the 54 fully vegetarian participants had a depressive disorder in the past year, against 10.3% of matched meat-eaters [9]. Among the fully and mostly vegetarian participants with a depressive disorder, though, the disorder had begun on average about five and a half years before they changed their diet, and only 34.4% had started the diet first [9]. The authors suggest that people with a mental disorder may turn to what they see as healthier eating, or become more sensitive to the suffering of animals [9]. Their survey’s question about meat would not, in German, have covered poultry, and for eating disorders the timing was different: going vegetarian was as likely to come before the disorder as after it [9].

A much larger 2026 study that followed the same people over time also finds little sign that eating less meat leads to depression. Tan et al. (2026) tracked 77,678 people aged 14 to 102 in representative samples from the Netherlands, Germany and Australia. After adjusting for income, age, education and gender, eating more meat went with only slightly less depression (β = -0.05), changes in a person’s meat eating barely tracked changes in their depression (β = -0.01), and in the tests of whether one predicted the other later on nothing was significant, so the authors concluded that eating little meat is not an important risk factor for depression [18]. The cross-sectional studies can’t settle the direction: the ELSA-Brasil authors say their design rules out conclusions about cause [10], and even the 2023 meta-analysis that favoured meat-eaters says the evidence precludes causal and temporal inferences [4].

Does diet quality explain the link?

Better diet quality goes with better mood in vegans and meat-eaters alike, but it does not explain the link away. An Australian online survey of 496 adults (Walsh et al., 2023) found that better-quality diets went with fewer depressive symptoms among omnivores, vegetarians and vegans alike, though it was a self-selected sample and its authors urge caution in comparing the diet groups [11]. A 2025 analysis of women in the Australian Longitudinal Study on Women’s Health found the same link in plant-based and omnivore groups, while warning that the effects were small [12]. A 2025 meta-analysis of 23 studies and 709,703 adults (Bizzozero-Peroni et al.) found that in cohort studies, people whose diets leaned most towards healthy plant foods had a lower risk of depression (risk ratio 0.77, 95% CI 0.67 to 0.88), while unhealthy plant-based diets went with more anxiety and depression; those studies scored how closely people in general adult populations followed plant-based patterns, rather than comparing vegans with meat-eaters [21]. A Brazilian study, ELSA-Brasil (Kohl et al., 2023), found the link with avoiding meat held even after accounting for nutrient intake, which suggests diet quality is not the whole story [10]. In a sample of 14,216 adults aged 35 to 74, the meat-free group had about twice the rate of depressive episodes, with a wide margin of uncertainty: a prevalence ratio of 2.05 (95% CI 1.00 to 4.18) before adjustment and 2.37 (95% CI 1.24 to 4.51) after adjusting for lifestyle, health, nutrient intake and how processed their food was [10].

Trials are scarce: the umbrella review counted six randomised trials across all nine reviews [1]. In one, a 2012 pilot, 39 omnivores were randomly assigned to keep eating meat, fish and poultry every day, to eat fish but no meat or poultry, or to go vegetarian, and after two weeks only the vegetarian group’s mood scores had improved, on several measures [13]. A trial published in 2025 in New Zealand found no difference either way: 80 healthy young adults who usually ate meat switched to an otherwise lacto-ovo vegetarian diet and were randomly assigned, by household, to three weekly servings of beef and lamb or of plant-based alternatives, and after 10 weeks their well-being, depression, anxiety and stress scores had changed no differently [20]. That trial was partly funded by trade associations for New Zealand’s meat exporters, which, the authors say, had no influence on its design, data collection or write-up [20]. Neither trial is large or long enough to settle the question.

Which nutrients matter for mood on a vegan diet?

Vitamin B12 needs care, because a deficiency can itself cause low mood: the NHS lists psychological problems ranging from mild depression or anxiety to confusion and dementia among its symptoms, and advises anyone with them to see a GP [14]. Sources for vegans are limited, says the NHS, which lists B12-fortified cereals, soya drinks and yeast extracts and says a supplement may be needed [15], so the B12 the objection worries about can come from fortified foods or a supplement. Researchers have also put forward shortfalls of iodine, iron, zinc and omega-3 fats, among others, as possible links [1], but in ELSA-Brasil, whose diet data came from a food questionnaire, adjusting for micronutrient and protein intake did not remove the gap, and its authors concluded that nutrient deficiencies do not explain it [10].

Where can I get help if my mood is low?

If your mood is low, talk to your GP or doctor, or call Samaritans free on 116 123 in the UK and Ireland, call or text 988 in the US and Canada, call Lifeline on 13 11 14 in Australia, or call or text 1737 in New Zealand. If you might act on thoughts of ending your life, or you are in danger now, call 999 or go to A&E in the UK [23], call 112 or 999 or go to an emergency department in Ireland, call 911 in the US and Canada, 000 in Australia or 111 in New Zealand. The NHS says it’s important to see a GP if you think you may be depressed, and not to delay [16]. If you take an antidepressant, don’t stop it suddenly or without talking to your doctor, and check the leaflet or ask a pharmacist whether any food or drink should be avoided with it [17].

If changing what you eat has become a way of eating less, eating-disorder charities can help: Beat in the UK, Bodywhys in Ireland, ANAD in the US, NEDIC in Canada, Butterfly Foundation in Australia and EDANZ in New Zealand.