WEDNESDAY, Feb. 18, 2026 (HealthDay News) -- A ketogenic diet (KD) may aid adults with treatment-resistant depression (TRD) in the short term, according to a study published online Feb. 4 in JAMA Psychiatry.In a randomized clinical trial (RCT), Min Gao, Ph.D., from the University of Oxford in the United Kingdom, and colleagues assessed whether a KD improves mental health outcomes in individuals with TRD. The analysis included 88 adults with TRD who were randomly assigned to either a six-week KD or a control phytochemical diet.The researchers found that depression severity decreased markedly in both groups, with a mean change in the 9-item Patient Health Questionnaire (PHQ-9) score from baseline to week 6 of −10.5 in the KD group and −8.3 in the phytochemical group. At weeks 6 and 12, the mean between-group differences in PHQ-9 scores were −2.18 and −1.85, respectively. The two groups were similar with respect to secondary outcomes. No serious adverse events were reported."This RCT found small improvements in depression in people with TRD when a KD was used as an adjunct to pharmacotherapy," the authors write. "However, adherence to the diet required intense support, and few patients chose to continue the diet after support withdrawal. Further work to develop a more comprehensive intervention is needed before further clinical testing."One author disclosed ties to the biopharmaceutical industry.Abstract/Full Text.Sign up for our weekly HealthDay newsletter