Supplements containing the mineral chromium may be useful in treating some cases of depression -- particularly when carbohydrate craving is a prominent symptom, a new study suggests.The study, of 113 people with a disorder known as atypical depression, found that although chromium picolinate supplements were no more effective than an inactive pill in relieving depression overall, they did appear to aid certain, mainly appetite-related, symptoms.Moreover, a subgroup of patients -- those who said they had “irrepressible cravings” for sweets and starches -- did show a general improvement in depression symptoms after taking the supplement.Exactly why chromium supplements seemed to aid these patients is not completely clear. However, the study authors speculate the improvements in the body’s use of insulin, the key hormonal regulator of blood sugar, may be the reason.