Estrogen–serotonin interactions: implications for affective regulation

Hormonal fluctuations associated with the menstrual cycle influence appetite control and eating behaviour. Energy intake varies during the reproductive cycle in humans and animals, with a periovulatory nadir and a luteal phase peak. Patterns of macronutrient selection show less consistency but a number of studies report carbohydrate cravings in the premenstrual phase, particularly in women with premenstrual syndrome. The cyclical nature of food cravings are frequently, but not invariably, associated with depression. Fluctuations in appetite, cravings and energy intake during the menstrual cycle may occur in parallel with cyclical rhythms in serotonin, which can be accompanied by affective symptoms. The premenstrual phase can be considered as a time when women are especially vulnerable to overconsumption, food craving and depression; this is often associated with low serotonin activity.

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Menstrual cycle and appetite control: implications for weight regulation.

Background Studies show that selective serotonin reuptake inhibitors are effective for severe premenstrual syndrome and premenstrual dysphoric disorder. This study compares the efficacy of a selective serotonin reuptake inhibitor with that of a tricyclic antidepressant to determine whether efficacy for premenstrual syndrome/premenstrual dysphoric disorder is a general or more serotonergic effect of antidepressants. Methods After 3 screening months, 189 subjects were randomized to sertraline hydrochloride, desipramine hydrochloride, or placebo for 3 months of double-blind treatment. The flexible dosage range was 50 to 150 mg/d. The outcome measures included the Penn Daily Symptom Report (DSR), the Hamilton Depression Rating Scale, the Clinical Global Impressions–Severity Scale, the Quality of Life Scale, and Patient Global Ratings of Functioning and Improvement. Analyses included all subjects with treatment data, with the last observation carried forward. Results Sertraline was significantly more effective than placebo or desipramine; desipramine was not better than placebo (F 2,163 =12.47, P P P =.05) were significant, and the results of all outcome measures were consistent. A history of depression, postmenstrual symptom levels, and other diagnostic variables added individually as covariates did not alter the treatment results. At end point analysis, DSR symptoms had decreased by more than 50% in 40 subjects (65%) in the sertraline group, 18 subjects (36%) in the desipramine group, and 16 subjects (29%) in the placebo group ( P Conclusions The comparison of 2 classes of antidepressants strongly favored the serotonergic drug, which effectively reduced symptoms and improved functioning and was well tolerated by women with severe premenstrual syndrome. A history of depression did not alter the treatment results.

https://jamanetwork.com/journals/jamapsychiatry/articlepdf/205408/yoa9079.pdf

Differential Response to Antidepressants in Women With Premenstrual Syndrome/Premenstrual Dysphoric Disorder: A Randomized Controlled Trial

Major depression is twice as common in women as men and depressive episodes appear to be more common in women with bipolar disorder. There is accumulating evidence that, in at least some women, reproductive-related hormonal changes may play a role in increasing the risk of depressive symptoms premenstrually, postpartum and in the perimenopausal period. In this review, the evidence for the role of hormonal fluctuations, specifically estrogen, in triggering depressive symptoms in a subgroup of women is summarized. In addition, the potential role of estrogen in triggering depressive symptoms via its effects on the serotonergic system, brain-derived neurotrophic factor and Protein Kinase C is reviewed.

The role of estrogen in mood disorders in women

The purpose of this article is to review the literature on the effects of the menstrual cycle on dependent variables in mood disorder research to inform investigators which physiological measures are likely to be significantly affected by menstrual cycle fluctuations and precisely how they might be affected. The following variables are discussed: prolactin; growth hormone; the hypothalamic-pituitary-thyroid axis (including thyrotropin, triiodothyronine, and thyroxine); the hypothalamic-pituitary-adrenal axis (cortisol, corticotropin, and beta-endorphin); melatonin; sleep; body temperature; and neurotransmitter activity (serotonergic and adrenergic systems). Body temperature and plasma and urinary norepinephrine vary predictably over the menstrual cycle. Prolactin and beta-endorphin may have peaks in the periovulatory phase, whereas serotonin levels in platelet-poor plasma may reach a nadir at that time. Triiodothyronine, thyroxine, cortisol, and melatonin do not appear to vary systematically over the course of the menstrual cycle, whereas the data for growth hormone, thyrotropin, corticotropin, and sleep are inconclusive.

Effects of the Menstrual Cycle on Dependent Variables in Mood Disorder Research

The effects of plasma and an aqueous plasma fraction from patients with premenstrual syndrome (PMS) and control subjects on the uptake of 5-hydroxytryptamine (5-HT) in washed human platelets and rat forebrain synaptosomes were studied. Pre- and postmenstrual samples of unextracted plasma from the control group significantly enhanced platelet uptake of 5-HT. In contrast, an aqueous fraction following extraction of the plasma with organic solvents caused a dose-dependent decrease of 5-HT uptake. Plasma obtained from patients with PMS caused less stimulation of 5-HT uptake compared to plasma from the control group. The aqueous fraction of premenstrual plasma from patients tended to inhibit 5-HT uptake to a greater extent than a similar plasma fraction from controls. The inhibition of 5-HT uptake was associated with an increase in Km. Aqueous plasma fractions from both groups also inhibited 5-HT uptake in brain synaptosomes. However, there were no significant differences between groups. The results of the platelet study suggest that there may be quantitative differences in the plasma concentration of endogenous factors that affect 5-HT uptake between patients with PMS and control subjects and that such differences may explain the previously reported alteration of platelet 5-HT uptake and content associated with PMS symptoms.

Alteration of 5-HT uptake by plasma fractions in the premenstrual syndrome.

Inhibition of serotonin uptake in rat brain synaptosomes by plasma from patients with premenstrual syndrome.

The present study determined the kinetic properties of platelet monoamine oxidase (MAO) in patients with premenstrual syndrome (PMS) and control subjects during the pre- and postmenstrual intervals. In addition, we investigated the effects of plasma obtained during the pre- and postmenstrual intervals from both subject groups on MAO activity in washed human platelets and rat brain synaptosomes. The Vmax of platelet MAO in postmenstrual PMS patients was significantly less than that during the premenstrual phase. Plasma from both subject groups (10–100 µl) inhibited platelet and synaptosomal MAO in a dose-dependent manner to approximately the same degree at each time interval. The results indicate that although human plasma contains endogenous substances which inhibit MAO activity, alterations in their concentration are probably not responsible for the previously reported transient changes in platelet MAO activity in PMS.

Darrell D. Franks

Papers

Alteration of 5-HT uptake by plasma fractions in the premenstrual syndrome.

Inhibition of serotonin uptake in rat brain synaptosomes by plasma from patients with premenstrual syndrome.

Effect of plasma from premenstrual syndrome and control patients on human platelet and rat brain synaptosome monoamine oxidase B activity.