Table 2.
Summary of Case Studies With KD in Schizophrenia
| Case | Gender and age | Primary diagnosis | Other psychiatric diagnoses | Medication | KD | Psychiatric symptoms (PANSS) | Metabolic features | Comments |
|---|---|---|---|---|---|---|---|---|
| Case #1 (63) | Male, 33 y | Schizoaffective disorder | ADHD, MDD | History: methylphenidate, amphetamine salts, dextroamphetamine, bupropion, sertraline, paroxetine, buspirone, lamotrigine, lorazepam, clonazepam, gabapentin, haloperidol, perphenazine, aripiprazole, olanzapine, quetiapine, and clozapine; lack of symptom control | Coffee with MCT oil and butter (“bulletproof coffee”), eggs, meat, fish, poultry, spinach, kale, and olive oil for 3 wk; ketosis measured by urine strips | Before KD: Total = 98 Positive = 27 Negative = 25 General = 46 After KD: Total = 49 Positive = 13 Negative = 8 General = 28 Symptoms worsened within 1–2 d after breaking KD | Before KD: 146 kg After KD: 98.9 kg [Weight loss of 47.2 kg after 1 y] | Completed certification course, successfully participates in online college program, has friends, began dating, lives independently |
| Case #2 (63) | Female, 31 y | Schizoaffective disorder | MDD, anorexia nervosa | History: sertraline, bupropion, amphetamine salts, lorazepam, lamotrigine, divalproex, topiramate, risperidone, aripiprazole, quetiapine, olanzapine, and clozapine; 23 ECT; lack of symptom control | Coffee, eggs, poultry, and lettuce for 4 mo | Before KD: Total = 107 Positive = 24 Negative = 29 General = 54 After KD: Total = 70 Positive = 15 Negative = 18 General = 38 Severe paranoia and delusion after breaking KD but improvement after a 3-d fast | Weight loss of 13.6 kg after 4 mo | Symptom control on previously insufficient dose of aripiprazole |
| Case #3 (64) | Female, 22 y (twin of case #4) | Schizophrenia (diagnosed at age 14) | None | For 5 mo before study: clozapine (300 mg), risperidone (6 mg), clonazepam (3 mg), and biperiden (6 mg) | 3:1 ratio KD plan set to standard 2000 kcal/d and mainly consisted of avocado, olive oil, butter, eggs, cheese, meat, spinach, and broccoli; for 15 d Ketosis determined by daily urine analysis | Before KD: Total = 101 Positive = 28 Negative = 16 General = 57 After KD: Total = 91 Positive = 26 Negative = 15 General = 50 | Before KD: BMI = 21.3 kg/m2 Body fat = 24.5% After KD: BMI = 19.8 kg/m2 Body fat = 19.8% | Blood clinical analysis remained unremarkable after KD |
| Case #4 (64) | Male, 22 y (twin of case #4) | Schizophrenia (diagnosed at age 18) | None | For 23 mo before study: levomepromazine (150 mg), quetiapine (100 mg), valproic acid (1000 mg), biperiden (6 mg), and risperidone (4 mg) | Same as case #3 | Before KD: Total = 82 Positive = 19 Negative = 18 General = 45 After KD: Total = 75 Positive = 16 Negative = 17 General = 42 | Before KD: BMI = 25.1 kg/m2 Body fat = 21.7% After KD: BMI = 22.9 kg/m2 Body fat = 16.8% | Blood clinical analysis remained unremarkable after KD |
| Case #5 (65) | Female, 82 y (same as in Ref. 62) | Schizophrenia (diagnosed at age 17) | None | Before start of KD in 2008: haldol-decanoate, risperidone, atenolol, furosemide, trazodone, and sertraline [Before 2008: lithium, olanzapine, ziprasidone, aripiprazole, lamotrigine, quetiapine, haloperidol, perphenazine, and risperidone] | Patient-directed KD initiated in 2008, maintains KD until today | Before KD: Chronic paranoia, disorganized speech, and both visual and auditory hallucinations, suicide attempts After KD: Marked reduction in psychotic symptoms; stopped taking all medication, hallucinations and paranoia remitted completely, improved mood, no suicidal ideations | Before KD: 150 kg After KD: 82 kg [Weight loss of 68 kg] | Regained her independence, no longer need a guardian |
| Case #6 (65) | Female, 39 y | Schizophrenia (hallucinations and paranoia started at age 14; diagnosed at age 24) | MDD, anxiety, anorexia nervosa | Haloperidol, clozapine, ziprasidone, risperidone, quetiapine, aripiprazole, olanzapine, sertraline, paroxetine, citalopram, fluoxetine, duloxetine, and venlafaxine | KD started in 2003 by functional medicine practitioner for symptoms of chronic gastrointestinal distress | Remained free of psychotic symptoms for past 5 y off antipsychotic medications | Weight loss of 32 kg, anorexia exacerbated, regained 13.6 kg, currently at normal body weight | Finished graduate school and works full time |
Abbreviations: ADHD, attention deficit hyperactivity disorder; ECT, electroconvulsive therapy; KD, ketogenic diet; MCT, medium chain triglyceride; MDD, major depressive disorder; PANSS, Positive and Negative Symptoms Scale.
Summary of case studies with ketogenic diet in schizophrenia. Reprinted with permission by Wolters Kluwer from Sarnyai et al., 2019.