TABLE.
Impact of the ketogenic diet (KD) in the treatment of various psychiatric disorders
|
Source |
Study Characteristics |
Intervention |
Outcomes |
|
Alzheimer Disease | |||
| Morrill and Gibas13 (2019) | Study design, duration: case report, 10 wk Setting: OP N = 1 | Low-carb, high-fat diet to produce sustained plasma ketones between 0.5 and 2 mg/dL | MoCA score increased from 21 to 28 Biometric changes: HOMA-IR decreased by 75% from 13.9 to 3.48 TG decreased by 50% from 170 to 85 mg/dL VLDL decreased by 50% from 34 to 17 mg/dL HbA1c decreased from 5.7% to 4.9% |
| Taylor et al14 (2018) | Study design, duration: pilot study, 31 mo Setting: OP N = 15 | KD, targeted macronutrient composition (70% fat), including MCT (10% total fat), 20% protein, and restriction of carbs (<10%); diet ratio of 1:1 (lipid to nonlipid) | 60% Reported some ketosis Serum β-hydroxybutyrate levels (mmol/L): Baseline: 0.11 1 mo: 0.52 2 mo: 0.34 3 mo: 0.31 (P < .001) Returned to 0.12 in 1-mo washout period MMSE (P < .05) and ADAS-Cog (P < .02) scores improved |
| Ota et al15 (2019) | Study design, duration: RCT, 12 wk Setting: OP N = 20 | MCT-ketogenic formula | No immediate benefit, but significant benefits in patients at 12 wk in WMS-R and WAIS-III (P < .05) |
|
Anorexia Nervosa | |||
| Scolnick et al16 (2020) | Study design, duration: case report, 6 mo Setting: OP N = 1 | KD, 2:1 to 1:1 ratio of fats to carbohydrates | Restrictive eating obsessions and compulsions stopped Continual improvement observed for >6 mo |
|
Autism Spectrum Disorder | |||
| Lee et al10 (2018) | Study design, duration: open-label clinical trial, 6 mo Setting: OP N = 15 | Modified ketogenic gluten-free diet regimen with supplemental MCT | ADOS-2 improvement at 3 mo: >7 units: 6 participants >3 units: 2 participants Little/none: 7 participants ADOS-2 improvement at 6 mo: Sustained improvement: 10 participants |
| Evangeliou et al17 (2003) | Study design, duration: pilot study, 6 mo Setting: IP N = 30 | John Radcliffe diet | Improvement in CARS score ranged from minor to significant in 60% of patients |
| Herbert and Buckley18 (2013) | Study design, duration: case report, 8 y Setting: OP N = 1 | GFCF KD | CARS score decreased from 49 to 17 Intelligence quotient increased by 70 points |
| Żarnowska et al19 (2018) | Study design, duration: case report, 6 mo on diet, 10 mo observation Setting: OP N = 1 | Low-carbohydrate, moderate protein, high-fat, KD | Intellect on WISC-R improved from baseline in the 16 mo following KD implementation |
| El-Rashidy et al20 (2017) | Study design, duration: case-control study, 6 mo Setting: IP N = 45 | MAD (n = 15) and GFCF diet (n = 15) vs control (n = 15) | CARS score mean decrease: MAD 41.7 → 33.7 (P = .0001) GFCF 39.17 → 34.27 (P = .001) Control no change ATEC score mean decrease: MAD 58 → 44 (P = .003) GFCF 64.13-42.13 (P = .0001) Control 62.82 → 61.60 |
|
Bipolar Disorder | |||
| Campbell et al21 (2019) | Study design, duration: observational analytic study Setting: OP N = 141 | KD, omega-3 enriched, or vegetarian | Reports of significant mood stabilization or remission of symptoms were substantially higher for the KD than for other diets |
| Phelps et al11 (2013) | Study design, duration: case series, 7 mo Setting: OP N = 2 | KD, 70% fat, 22% protein, 8% carbs | Mood stabilization exceeded the improvement achieved with medication |
|
MDD | |||
| Cox et al22 (2019) | Study design, duration: case report, 12 wk Setting: OP N = 1 | KD, 65% fat, 25% protein, 10% carbs | PHQ-9 score decreased Biometric changes: HbA1c dropped from 8% to 5.4% Average daily glucose measurements declined from 216 to 96 mg/dL HOMA-IR and TG/HDL ratios improved by 75% |
|
Narcolepsy | |||
| Husain et al12 (2004) | Study design, duration: clinical trial, 8 wk Setting: OP N = 9 | KD, consisting of <20% carbs/d | NSSQ total score decreased by 18% (P < .0019) |
|
Schizophrenia | |||
| Kraft and Westman23 (2009) | Study design, duration: case report, 12 wk Setting: IP N = 1 | KD, <20 g carbs/d | Auditory and visual hallucinations stopped Continual improvement observed for 12 mo |
ADAS-cog = Alzheimer's Disease Assessment Scale-Cognitive Subscale; ADOS-2 = Autism Diagnostic Observation Schedule Second Edition; ATEC = Autism Treatment Evaluation Checklist; CARS = Childhood Autism Rating Scale; GFCF = gluten-free–casein-free; HOMA-IR = Homeostatic Model Assessment of Insulin Resistance; IP = inpatient; MAD = modified Atkins diet; MCT = medium-chain triglycerides; MMSE = Mini-Mental State Examination; MoCA = Montreal Cognitive Assessment; NSSQ = Narcolepsy Symptom Status Questionnaire; OP = outpatient; PHQ-9 = Patient Health Questionnaire; RCT = randomized control trial; TG = triglycerides; T2DM = type 2 diabetes mellitus; WAIS-III = Wechsler Adult Intelligence Scale-3rd edition; WISC-R = Wechsler Intelligence Scale for Children-Revised; WMS-R = Weschsler Memory Scale-revised.