2003
Jonathan R.T. Davidson, M.D., Kurian Abraham, M.D., Kathryn M. Connor, M.D., Malcolm N. McLeod, M.D. Effectiveness of chromium picolinate in atypical depression: a placebo-controlled clinical trial, Biological Psychiatry [In press, 2003]

In this 15-patient pilot study, researchers at Duke University Medical Center evaluated the benefits of chromium picolinate (CP) for depression in an eight-week double-blind, placebo-controlled, randomized clinical trial. Patients in this study had major depression accompanied by symptoms of weight gain, carbohydrate cravings and unexplained fatigue. Patients were given either 400-600 mcg per day of elemental chromium as CP, or a placebo. The results of the study showed that 70 percent (7/10) of the patients receiving CP significantly responded to supplementation, this compared to a 0 percent (0/5) response in patients receiving a placebo. A beneficial response was considered significant if the patient’s symptoms of depression were reduced by more than 66 percent. These antidepressant effects were seen without any side effects and without any additional prescription drug medications. Duke researchers concluded that CP administration showed promising antidepressant effects in this patient population.

2002
Attenburrow, J. Odontiadis, B.J. Murray, P.J. Cowen, M. Franklin. Chromium treatment decreases the sensitivity of 5-HT2A receptors, Psychopharmacology 159:432-436, 2002

In this study, researchers at the University of Oxford, U.K., evaluated the effects of chromium picolinate (CP) supplementation on brain function. The authors overall findings point to CP’s beneficial blocking of a critical receptor in the brain. Similar effects have been produced by pharmaceutical antidepressants, like imipramine. The authors say their findings show that giving CP for a short-term lowers the body’s endocrine responses to stimulation believed to be clinically related to indicators of mood and depression. In fact, say the researchers, these effects of CP on mood may be especially important in depressed patients with diabetes.

2000
Malcolm N. McLeod, M.D., and Robert N. Golden, M.D. Chromium treatment of depression International Journal of Neuropsychopharmacology 3:311-314, 2000

The effects of giving chromium by itself in a case series of eight patients with hard-to-treat mood disorders (e.g., major depressive episodes, bipolar II disorder, and panic attacks/rage outbursts) are outlined by University of North Carolina psychiatrists. Overall, the patients experienced dramatic clinical response to chromium for chronic, hard-to-treat mood disorders that were present for years and unresponsive to conventional therapies. The authors state: “All of the patients experienced clinical remissions, which enabled them to return to more productive levels of functioning without any significant depressive symptoms.” Interestingly, most of the patients—a varied group of people with disparate conditions—had carbohydrate cravings and excessive appetite prior to chromium administration. The researchers explain that “chromium has well-described effects on carbohydrate metabolism and increases the efficiency of insulin utilization.” In line with this, and these results, the authors suggest that the “dramatic impact of chromium in normalizing appetite in these patients” may relate to its role in sugar and insulin metabolism. This may be a clue to the mechanism of action for chromium’s antidepressive abilities.

1999
Malcolm N. McLeod, M.D., Bradley N. Gaynes, M.D., M.P.H., and Robert N. Golden, M.D. Chromium potentiation of antidepressant pharmacotherapy for dysthymic disorder in 5 patients Journal of Clinical Psychiatry 60(4):237-240, 1999.

Recognizing the difficult-to-treat nature of dysthymic (mood) disorder, the authors identified “the need for pharmacologic potentiation strategies.” In this case series, University of North Carolina psychiatrists report their experience using chromium supplementation as an adjunct to drug therapy in five patients with long-term (dysthymic) depression. In this paper, which was “the first report of the use of chromium in the pharmacotherapy of a psychiatric disorder,” rapid responses to chromium supplementation were described, in cases with pharmaceutical preparations and in cases without. The speed of response to chromium supplementation—largely using the picolinate form—suggests, say the authors, that the mineral may “exert mood-elevating effects” independent of any underlying mood disorder. As to the possible mechanisms by which these effects are produced, the authors believe that part of the answer may lie in chromium’s boosting of glucose utilization in the central nervous system, including the brain. Another possibility, suggest the authors, is that chromium may indirectly enhance brain neurotransmitter function. The researchers conclude by saying, “Preliminary observations suggest that chromium may [improve the efficacy of] antidepressant [drugs] for dysthymic disorder.”