The relationship between ECT nonresponsiveness and calcification of the pineal gland in bipolar patients

It has been suggested recently that the therapeutic effects of electroconvulsive therapy (ECT) may be mediated in part through stimulation of pineal melatonin secretion. If melatonin does mediate the antidepressant effects of ECT and depression itself is associated in some patients with reduced melatonin secretion, patients with reduced melatonin secretion could respond less readily to ECT. There is evidence to suggest an inverse relationship between melatonin secretion and the degree of pineal calcification. Specifically, heavy pineal calcifications in animals have been reported to be associated with reduced plasma melatonin levels. In this study, an investigation was conducted to establish more precisely the relationship between the clinical response to ECT in 17 bipolar patients and the degrees of pineal calcification present on CT scan. There was a significant association between ECT nonresponsiveness and the presence of pathologically enlarged pineal calcification (i.e., greater than 1 cm in diameter) (p.01). In addition, there was a significant difference in ECT responsiveness in patients without pineal calcification compared to those with pathologically enlarged pineal calcification (F = 6.10; p = .01, one-way ANOVA). These findings indicate an association between enlarged pineal calcification and ECT nonresponsiveness and suggest that reduced melatonin secretion may be associated with ECT nonresponsiveness. An enlarged pineal calcification could be a useful radiological marker of ECT nonresponsiveness and administration of melatonin precursors (i.e., L-tryptophan; 5-HTP) and its cofactors (i.e., pyridoxine, folate) as well as melatonin-release enhancing agents (i.e., 5-methoxypsoralen) prior to ECT might augment its antidepressant effects in bipolar patients.