QUESTION: Dear Dr. McLeod,
I read about the study of 113 depressed patients who received either chromium or placebo for 8 weeks. Why didn’t more of them benefit from from chromium? I find this surprising since chromium has helped curb my appetite, has allowed me to lose weight (because I have more energy to exercise), and it has lifted my depression. It has been wonderful for me. Will you explain why more people in the study didn't benefit from chromium?
ANSWER: Yes, I'll certainly try to.
Dr. John P. Docherty was the lead investigator of the study to which you are referring. At the time he was CEO of Comprehensive NeuroScience Inc., and Professor of Psychiatry at Weill Medical College of Cornell University in New York, NY.
One hundred thirteen patients were enrolled in
study, which was double-blinded. It was conducted at multiple centers across the US, and lasted for 8 weeks. The plan was to give 600 micrograms daily of chromium picolinate (CrPic) to 75 of the patients; 38 were to receive a placebo or “dummy” pill. The patients’ responses were to be assessed by the 29-item Hamilton Depression Rating Scale (HAM-D-29) and the Clinical Global Impressions Improvement Scale (CGI-I).
Of the 113 patients who were enrolled in the study, 3 dropped out before taking a single dose of the capsules that contained either CrPic or placebo. Another 35 did not comply with the study design, that is, they failed to take at least 80% of the capsules, and therefore were excluded from analysis of the data. This left only 75 of the original 113 who completed the study. Of the 75 who completed the study,
only fifty (50) received CrPic, while 25 received placebo.
TheCrPic group reported more benefit than placebo in reducing appetite, reducing eating, decreasing carbohydrate craving, and “smoothing out” daily mood swings. As measured by the overall HAM-D-29 scores, both groups improved. However, CrPic was no better than placebo. This may have been because not everyone is this group craved carbohydrates and not everyone was overweight. In other words, not all patients suffered from atypical depression.
Let us look at only those 41 patients who were overweight and who craved carbohydrates: twenty six, (26) received CrPic and 15 received placebo. Those who received CrPic had significantly greater improvement, as measured by the total HAM-D-29 scores, than did those receiving placebo (65% vs 33%). Moreover, those receiving CrPic reported significantly greater improvement in terms of appetite control, reduced eating, and reduced carbohydrate craving.
To look at the results in round numbers, analysis of the study results suggests that 2 in 3 depressed people who are overweight and chronically hungry will respond to chromium while only 1 in 3 will respond to placebo. This analysis of the data supports my observation that chromium lifts depression and curbs appetite in overweight, depressed people.
Thank you very much for your question.
Malcolm N. McLeod, MD