Reduced platelet tritium-labeled imipramine binding sites in women with premenstrual syndrome

Objective: We studied the possible role of serotonergic systems in the cause of premenstrual affective symptoms. Study Design: The binding of tritium-labeled imipramine to platelets is thought to parallel central nervous system binding and to indicate serotonergic activity. We measured platelet tritium-labeled imipramine binding sites in the follicular and luteal phases in 12 controls and in 9 women with well-documented late luteal phase dysphoric disorder. In statistical analyses we used repeated measures analysis of variance, with Student-Newman-Keuls and Duncan's one-tailed t tests, and Pearson's r. Results: The values of subjects with late luteal phase dysphoric disorder were lower than those of controls (F [1,39] = 5.13, p = 0.03). Both follicular and luteal phase levels were lower in subjects with late luteal phase dysphoric disorder but reached statistical significance only in the follicular phase. Conclusion: Lower platelet tritium-labeled imipramine binding in women with late luteal phase dysphoric disorder supports the hypothesis that alteration of central serotonergic systems may contribute to premenstrual dysphoric symptoms.