C.D. is a 70 year-old Caucasian female with a diagnosis of schizophrenia since the age of seventeen. Her diagnosis was based on paranoia, disorganized speech, and hallucinations. She reported both auditory and visual hallucinations, including seeing skeletons and hearing voices that told her to hurt herself. According to her history, she has had these hallucinations on almost a daily basis since the age of seven. C.D. has also been hospitalized at least five times over the last six years for suicide attempts and increased psychotic symptoms. She has attempted to overdose on medications, cut herself, and ingest cleaning agents. Her most recent hospitalization was five months prior to initiating the low-carbohydrate diet. She has discussed both her suicidal ideations and her hallucinations with her psychiatrist who has tried to optimize her medication regimen in an effort to improve her symptoms, but this has been largely unsuccessful. Her prior anti-psychotic and mood-stabilizing medication regimen has included lithium 900 mg qhs, olanzapine (dose unknown), ziprasidone 40 mg bid, aripiprazole 30 mg qhs, lamotrigine 100 mg bid, and quetiapine 900 mg qhs. She is currently managed on risperidone 4 mg qhs.
C.D.'s other medical problems (and approximate year of diagnosis) included obesity (1950's), hypertension (1970's), depression (1940's), obstructive sleep apnea (2002), gastroesophageal reflux disease (2003), urinary incontinence (2002), glaucoma (1999), trochanteric bursitis (2004), peripheral neuropathy of unknown etiology (2006), and prior cholecystectomy (1978). Her current medications included atenolol 100 mg daily, furosemide 20 mg daily, trazodone 100 mg qhs, sertraline 100 mg daily, timolol eye drops 1 drop each eye bid, brimonidine eye drops 1 drop each eye bid, and vitamin E 400 IU every other day.
A typical day's diet consisted of the following: egg and cheese sandwich, diet soda, water, pimento cheese, barbequed pork, chicken salad, hamburger helper, macaroni and cheese, and potatoes. She rated her baseline fatigue as a "3" using a standardized questionnaire (0 = none, 4 = severe or frequent). Her body weight was 141.4 kilograms (BMI 52.6 kg/m2), sitting blood pressure (BP) was 130/72 mmHg, and pulse was 68 beats per minute. Physical examination showed an obese, mildly disheveled female with poor attention to hygiene, but was otherwise unremarkable. She was instructed how to follow a dietary regimen consisting of unlimited meats and eggs, 4 ounces of hard cheese, 2 cups of salad vegetables, and 1 cup of low-carbohydrate vegetables per day. This diet restricts carbohydrate intake to fewer than 20 grams per day .
She returned for a follow-up appointment 7 days after starting the low-carbohydrate diet. She was feeling well, and noted an increase in energy. She was seen again in clinic 19 days later. When asked how she was doing, she responded that she was no longer hearing voices or seeing skeletons. She first noticed this upon awakening about 8 days after starting the program. She had had no change in medication. The only change had been in her dietary intake which now consisted of beef, chicken, turkey, ham, fish, green beans, tomatoes, diet drinks, and water. She denied hunger. C.D. was very happy that she was no longer hearing voices, and believed that it made her calmer. Her body weight was 136.2 kilograms, sitting BP was 150/84 mmHg, and pulse was 76 beats per minute.
Over the course of 12 months, C.D. has continued the low-carbohydrate, ketogenic diet and has had no recurrence of her auditory or visual hallucinations. She has also continued to lose weight (body weight 131.4 kilograms) and experience improvements in her energy level. She acknowledged having 2–3 isolated episodes of dietary non-compliance that lasted several days, where she ate pasta, bread, and cakes around the winter holidays; however she had no recurrence of her hallucinations.