Inositol in bipolar disorder
Inositol, a glucose isomer precursor of phosphatidyl inositol linked to the second messenger system, has been found to be more effective than placebo in the treatment of depression and other psychiatric illnesses, including panic disorder. Doses in the relevant studies have ranged from 12,000 to 20,000 mg/day.146 Inositol, a vitamin-like substance found in many plants and animals, can be produced synthetically. A randomized controlled trial in 24 bipolar patients given inositol or placebo found no significant differences between the treatment groups. However, a trend towards improvement on inositol led researchers to recommend that larger studies be performed.147–148 Another study of 66 bipolar I or II patients with resistant depression examined the benefits of augmenting mood stabilizers with lamotrigine, inositol, or risperidone, and found that the rate of recovery was 23.8% with lamotrigine, 17.4% with inositol, and 4.6% with risperidone.149 Nierenberg et al suggested that patients with treatment-resistant depression are suitable candidates for inositol augmentation. However, at therapeutic doses, inositol frequently causes flatulence and occasionally induces mania.149