Fiza Singh, MD Center of Recovery Education San Diego VA Medical Center Associate Clinical Professor Department of Psychiatry University of California San Diego San Diego, California
Andrew Allen, MD Attending Psychiatrist Aurora Behavioral Health-San Diego Achieve Medical Center San Diego, California
Disclosures The authors report no financial relationships with any companies whose products are mentioned in this article, or with manufacturers of competing products.
Melatonin is a naturally occurring hormone that is available over-the-counter and is frequently used to treat insomnia. Melatonin appears to have few adverse effects, is not habit-forming, and is inexpensive. It is a hormone produced primarily by the pineal gland, although it is also produced by many other cell types, including the skin, gut, bone marrow, thymus, and retina.21,22 Melatonin is a highly conserved essential hormone23 that acts via both G protein-coupled membrane bound receptors and nuclear receptors.23-25 Its ability to function both intra- and extracellularly implies it has an essential role in maintaining homeostatic mechanisms. Melatonin’s putative mechanism of action may derive from its effects on circadian rhythms, which in turn affect systolic blood pressure, glycemic control, and oxidative stress. In rodents, pinealectomy led to the rapid development of hypertension and metabolic syndrome. Daily administration of melatonin26 in these animals restored metabolism by decreasing abdominal fat and plasma leptin levels. These studies suggest that melatonin plays a central role in metabolism.
A recent study of patients with first-episode psychosis (n = 48) examined the effects of melatonin (3 mg/d) as an add-on treatment to olanzapine vs placebo.27 Compared with those in the placebo group, participants in the melatonin group experienced a statistically significant decrease in body weight, BMI, waist circumference, and triglyceride levels.27 In another study, the melatonin receptor agonist ramelteon was used in conjunction with SGAs.28 Augmentation with ramelteon led to significantly lower rises in total cholesterol levels compared with placebo.28
When recommending melatonin for a patient with schizophrenia, suggest that he/she begin by taking a starting dose of 3 mg nightly.
Weighing the options
Which medication to prescribe for a patient such as Mr. N would depend on the patient’s specific complaint/health target.
Weight gain or diabetes. If the patient’s primary concerns are avoiding weight gain or the development of diabetes, metformin is an excellent starting point.
