Estrogen-serotonin interactions: implications for affective regulation

The role of central serotonergic dysfunction in the aetiology of premenstrual dysphoric disorder: therapeutic implications

Premenstrual dysphoric disorder (PMDD), as defined in DSM-IV, is a mood disorder. One of the leading theories for the pathogenesis of mood disorders is dysfunction of the serotonergic system. An increasing database suggests that serotonergic dysfunction also characterises PMDD. Evidence that treatments which enhance serotonergic function are beneficial in reducing the symptoms of PMDD support this hypothesis. Indeed, most of the evidence from baseline studies suggests predominantly a serotonergic rather than a noradrenergic or dopaminergic dysfunction. Challenge studies further support this hypothesis. These findings of neurotransmitter dysfunction are more consistent than those of other neuroendocrine abnormalities for example. Based on treatment studies, a selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitor, fluoxetine, has been approved for use in PMDD by the US Food and Drug Administration.

Altered response to meta-chlorophenylpiperazine in anorexia nervosa: support for a persistent alteration of serotonin activity after short-term weight restoration

OBJECTIVE

Patients with anorexia nervosa (AN) have disturbances of appetite and behaviors, such as dysphoria, inhibition, and obsessions, that could be related to altered serotonin activity. To investigate such relationships, we administered meta-chlorophenylpiperazine (m-CPP), a relatively serotonin-specific drug.

METHODS

To avoid the confounding effects of malnutrition or weight loss, we studied 12 patients with restricting-type AN between 5 and 17 days after a return to a normal weight and while on a stable dietary intake. We compared them to 12 healthy control women (CW). m-CPP was administered double blind and placebo controlled.

RESULTS

Although weight restored, AN women had lower body weight and increased ratings for depression and obsessionality compared with CW. After m-CPP, AN women had an elevation in mood and a reduction in body image distortion when compared with placebo. After m-CPP, groups had similar cortisol, adrenocorticotropin (ACTH), and growth hormone responses whereas AN women had an uncertain reduction in prolactin response.

DISCUSSION

These data support other studies that suggest that altered serotonin activity persists after weight restoration in AN patients. The finding that m-CPP temporarily improved mood and reduced body image distortions supports the hypothesis that altered serotonin activity may contribute to the pathophysiology of AN.

Evaluation of a unique oral contraceptive in the treatment of premenstrual dysphoric disorder

Premenstrual dysphoric disorder (PMDD) is a severe form of premenstrual syndrome (PMS). This is the first trial of a unique oral contraceptive containing a combination of drospirenone (DRSP, 3 mg) and ethinyl estradiol (EE, 30 microg) for the treatment of PMDD. DRSP is a spironolactone-like progestin with antiandrogenic and antimineralocorticoid activity. Spironolactone has been shown to be beneficial in PMS, whereas oral contraceptives have shown conflicting results. In this double-blind, placebo-controlled trial, 82 women with PMDD (Diagnostic and Statistical Manual of Mental Disorders, 4th ed. [DSM IV]) were randomized to receive DRSP/EE or placebo for three treatment cycles. The primary end point was change from baseline in luteal phase symptom scores as assessed on the Calendar of Premenstrual Experiences (COPE) scale. Patients treated with DRSP/EE showed a numerically greater change from baseline compared with those treated with placebo on each of the 22 COPE items and each of the 4 symptom factors. Between-group differences in symptom improvement reached statistical significance in factor 3 only (appetite, acne, and food cravings, p = 0.027). The secondary end points, Beck Depression Inventory (BDI) and Profile of Mood States (PMS), were consistent with the primary end point in that patients treated with the oral contraceptive showed a numerically greater improvement from baseline compared with those treated with placebo. The results of this study show a consistent trend in the reduction of symptoms that suggested a beneficial effect of DRSP/EE for the treatment of PMDD, despite limitations of the study design.

A scheme of combined oral contraceptives for women more than 40 years old

OBJECTIVE

To study whether the addition of estrogen to the 7 hormone-free days of a combined oral contraceptive (OC) cycle improves the symptomatology in perimenopausal women with climacteric complaints.

DESIGN

A total of 56 women in their forties presenting with mood disorders and/or hot flashes were included in this randomized double-blind study. Symptoms were evaluated using the Greene test. Subjects were allocated into two groups: 23 women received an OC containing 20 microg of ethinyl-estradiol and 150 mg of desogestrel for 21 days and then 7 placebo tablets (placebo group); the other 33 women received 21 tablets with the same hormone combination, followed by 2 placebo tablets and 5 ethinyl-estradiol tablets of 10 microg each (estrogen group). After three cycles, symptoms were reassessed.

RESULTS

Symptoms were similar in the two groups at the start of the study. Three months later, vasomotor symptoms in the placebo group dropped from 3.3 +/- 1.7 to 1.7 +/- 1.8, and in the estrogen group, from 3.0 +/- 1.7 to 0.7 +/- 0.9 (p < 0.04). Similarly, symptoms of depression fell from 8.8 +/- 4.0 to 6.7 +/- 3.9 in the placebo group and from 10.3 +/- 3.5 to 3.8 +/- 2.9 in the estrogen group (p < 0.002). Somatic symptoms fell with placebo from 10.9 +/- 5.3 to 7.4 +/- 5.4, and with estrogen, from 9.7 +/- 4.9 to 4.0 +/- 2.5 (p < 0.03). Sexual dysfunction as measured by the Greene Scale (loss of sexual interest) also improved more in women who received additional estrogen: 2.0 +/- 0.9 to 0.5 +/- 0.9 vs. 1.8 +/- 1.2 to 1.2 +/- 1.2, p < 0.03. Anxiety symptoms improved in both groups but without any significant difference between them.

CONCLUSIONS

Adding 5 days of estrogen to the classic contraceptive scheme improves the climacteric symptoms of perimenopausal women who use OCs.

Epilepsy, depression and antidepressant drugs

Apart from constituting an important management problem, depression coexisting with epilepsy is also an interesting psychiatric phenomenon, with multiple interacting biological, psychological and social factors involved in its causation. New research approaches to the study of epilepsy and depression, including neuroimaging, neurochemical and neuroendocrine techniques, and the arrival of new classes of antidepressants in recent years, suggest it is timely to reconsider this topic. We review current knowledge of the prevalence and causes of interictal depression in epilepsy, focussing mainly on neurobiological factors, and give an overview of recent concepts concerning the management of depression. We also discuss pharmacological treatment of depression in epilepsy, focussing on the association between antidepressants and seizures, and drug interactions.

Intermittent, luteal phase nefazodone treatment of premenstrual dysphoric disorder

Three outpatients who fulfilled full DSM-IV diagnostic criteria for premenstrual dysphoric disorder (PDD) were successfully treated with intermittent (luteal phase) nefazodone. They received the medication at low doses of up to 100 mg/day (50 mg b.i.d.), for 2 weeks through the luteal phase of the menstrual cycle only. All the patients reported a marked symptomatic improvement, including full remission of their emotional symptoms, and two achieved in addition full remission of their somatic symptoms. Side-effects reported during the treatment were mild. The use of luteal phase nefazodone seems to be a promising treatment strategy for the management of PDD. It offers advantages over daily dosing throughout the menstrual cycle, such as reduced incidence and severity of side-effects, and avoids the stigma that may accompany the continuous use of psychopharmacological treatment, with the advantage that compliance may be improved.

Neuropeptide Y in male and female brains of Flinders Sensitive Line, a rat model of depression. Effects of electroconvulsive stimuli

Human and animal studies suggest that neuropeptide Y (NPY), a peptide co-localized and co-released with classical neurotransmitters, is involved in the pathogenesis of affective disorders. In addition, lithium, electroconvulsive treatments (ECT in humans and ECS in rodents) and antidepressants affect NPY in a specific temporal- and brain-region fashion. These results have been obtained on healthy male rats; females and/or "depressed" animals have essentially not been studied. Consequently, we studied brain NPY-like immunoreactivity (-LI) under basal conditions and following a series of ECS in both male and female Flinders Sensitive Line (FSL), an animal model of depression, and their controls, the Flinders Resistant Line (FRL) rats. Furthermore, we examined whether the oestrus cycle affects NPY-LI in these strains. Following sacrifice by focused microwave irradiation, the peptides were extracted from dissected brain regions and measured by radioimmunoassay. Hippocampal NPY-LI in both sexes was significantly lower in the "depressed" FSL compared to the control FRL. ECS increased NPY-LI in both male and female rats in both FSL and FRL strains in hippocampus, frontal cortex and occipital cortex. In the hypothalamus, the increase was found only in the FSL rats. In both FSL and control rats, the basal NPY-LI was lower in the hippocampus of female compared to male rats. NPY-LI did not vary during the different phases of the oestrus cycle. These results suggest that the gender differences are not due to NPY-LI variations during the oestrus. The results are consistent with our hypothesis that NPY plays a role in the pathophysiology of depressive disorders and provide further evidence that one of the modes of ECS action is to elevate NPY in the limbic system. Assumption that gender differences in NPY could explain increased rates of depression in women is speculative, but is in line with the findings in the present study.

Effects of estradiol and progesterone administration on human serotonin 2A receptor binding: a PET study

BACKGROUND

Preclinical studies demonstrate that 17beta-estradiol (E(2)) increases serotonin-2A receptor (5-HT(2A)R) density in rat frontal cortex.

METHODS

We investigated the impact of hormone replacement therapy on 5-HT(2A)R binding potential (BP) using positron emission tomography and [(18)F]altanserin in five postmenopausal women. Subjects were imaged at baseline, following 8 to 14 weeks of transdermal E(2), 0.1 mg/d, and following 2 to 6 weeks of E(2) plus micronized progesterone (P) 100 mg per os twice daily. Regional BPs in the anterior cingulate cortex, dorsolateral prefrontal cortex, and lateral orbitofrontal cortex were calculated by Logan analysis.

RESULTS

There was a main effect of time (p = .017) for 5-HT(2A)R BP, which increased 21.2%+/-2.6% following combined E(2) and P administration relative to baseline. This effect was evident in all cerebral cortex regions examined.

CONCLUSIONS

5-HT(2A)R BP increased in widespread areas of the cerebral cortex following combined E(2) + P administration.

Menopause and mood. Is depression linked with hormone changes?

For most women, the perimenopause is not associated with depression. In those who do become depressed, mood symptoms tend to decrease at the end of menopause, regardless of previous history of depression. Many of the changes in brain function that affect mood are secondary to changing estrogen levels in the brain. Treatment with estrogen alone may improve mood in women with mild depressive symptoms, but those unresponsive to estrogen and women who have moderate to severe depression need antidepressant therapy.

Postmenopausal estrogen therapy and depressive symptoms in older women

BACKGROUND

Evidence regarding the effect of postmenopausal estrogen therapy on mood is limited.

METHODS

To determine whether postmenopausal estrogen therapy is associated with fewer depressive symptoms in elderly women, we conducted a cross-sectional study of 6, 602 white women ages 71 years or older who were recruited from population-based listings in Baltimore, Md; Minneapolis, Minn; Portland, Ore; and the Monongahela Valley, Pa. Use of estrogen and progestin was determined by interview. Participants completed the Geriatric Depression Scale short form (GDS) and were considered depressed if they reported 6 or more of 15 possible symptoms of depression.

RESULTS

A total of 6.3% (72/1,150) of current estrogen users, 7.2% (142/1,964) of past estrogen users, and 9.0% (313/3,488) of never users reported 6 or more symptoms of depression (P =.004). Current estrogen users had a decreased risk of reporting 6 or more depressive symptoms, compared with not current (past or never) users of estrogen (odds ratio [OR], 0.7; 95% CI, 0.5 to 0.9; P =.01], adjusted for living alone, bilateral oophorectomy, current smoking, physical activity, social network, self-perceived health, cognitive function, functional status, and antidepressant use. However, excluding women who use estrogen or progestin alone, we were unable to find an association between current use of combined estrogen plus progestin therapy and depressive symptoms (adjusted OR, 0.8; 95% CI, 0.5 to 1.4; P =.5).

CONCLUSIONS

This cross-sectional study found that current use of unopposed estrogen was associated with a decreased risk of depressive symptoms in older women. Additional studies are needed to understand the effect of combined estrogen and progestin therapy on the prevalence of depressive symptoms in older women.

Tryptophan levels, excessive exercise, and nutritional status in anorexia nervosa

OBJECTIVE

It has been hypothesized that reduced dietary availability of tryptophan may be the cause of impaired serotonin activity in underweight anorexics. The study reported here evaluated the relationship between tryptophan availability in the blood and nutritional status in anorexia nervosa.

METHODS

The total amount of tryptophan and the ratio between tryptophan and other large neutral amino acids (TRP/LNAA) were assessed in a sample of 16 starving anorexic patients. Body weight and composition and energy intake were evaluated in all patients. All subjects also completed self-reported questionnaires such as the Hopkins Symptom Checklist and Eating Disorders Inventory (EDI).

RESULTS

The TRP/LNAA ratio seems to be higher in patients with a more severe catabolic status. It is, in fact, significantly inversely correlated with body mass index, body fat, muscle mass, daily energy intake, and daily tryptophan intake. The TRP/LNAA ratio also correlates with growth hormone and the EDI drive for thinness. Patients who exercise excessively had significantly higher TRP/LNAA ratios.

CONCLUSIONS

In starving anorexic patients, the TRP/LNAA ratio does not seem to be determined by the content of tryptophan in the diet, but it correlates with measures of catabolism. The relationship of the TRP/LNAA ratio to excessive exercise and starvation indicates the importance of further investigations exploring the role of tryptophan availability in maintaining anorexia nervosa.

The relationship between menstrual cycle phases and suicide attempts

OBJECTIVE

The validity of prior studies on the menstrual cycle and suicide attempts assumes that suicidal women accurately describe their cycles. The three objectives of this study were 1) to explore whether prior inconsistencies are due to the effects of sample selection and method of assessment of the menstrual cycle, 2) to assess the relationship between the menstrual cycle phase and suicide attempts, and 3) to establish the role of sexual hormones in suicide attempts.

METHODS

The original sample included 134 women who came to the emergency room of a general hospital after a suicide attempt. One hundred eight female blood donors were recruited as control subjects. The menstrual cycle was divided into follicular, midcycle, and luteal phases using two clinical methods and serum hormonal assessment. Dividing the follicular phase into menstrual and nonmenstrual phases was also considered.

RESULTS

Two of 11 previously used sampling methods produced a sample size similar to that of the hormonal assessment. kappa values between the two clinical and the endocrinological methods were low (0.40-0.50). The number of suicide attempts during the follicular phase (particularly during the menstrual phase) was significantly higher than expected.

CONCLUSIONS

Despite the inability to control for other variables and limitations, the results of this study suggest that sample selection could introduce biases and that studies relating psychiatric symptomatology and menstrual cycle phases need to use hormonal determinations. New studies are needed to verify that suicide attempts are more frequent during the follicular phase (particularly during the menstrual phase).

Is there sexual dimorphism in obsessive-compulsive disorder?

The present review addresses the question of sexual dimorphism in obsessive-compulsive disorder. It enumerates examples that could be interpreted to suggest the existence of such dimorphism from the fields of epidemiology, phenomenology, pharmacology, neuropsychology, neuroimaging and genetics. We conclude that data, at this point, are too scarce to warrant a firm conclusion. On the contrary it seems that there are enough indications in the literature that hint at the possibility of sexual dimorphism to stimulate further research in the field.

Sex playing with the mind. Effects of oestrogen and testosterone on mood and cognition

Women now spend more than 1/3 of their lives in a state of oestrogen deprivation as a result of increased life expectancy. A similar, but milder, hypogonadal state has been described for elderly men. This paper aims to review the available literature on the effects of both oestrogen and testosterone on mood and cognition. Oestrogen replacement therapy of postmenopausal women is associated with improvements in measures of well being and decline in depression scores. In addition, oestrogen seems to augment the response of postmenopausal women with major depression to antidepressant treatment. Most studies designed to investigate the impact of oestrogen on cognition indicate that replacement therapy is associated with better performance on neuropsychological tests, particularly in measures of verbal memory and fluency. The data also supports claims that oestrogen replacement therapy reduces the risk of Alzheimer's disease in later life and improves response of patients to anticholinesterase treatment. Data on the effects of testosterone is sparser. Preliminary findings suggest that testosterone therapy may improve mood when used in isolation or in association with oestrogen. The effects of testosterone on cognitive functioning are less clear--some studies indicate that the administration of testosterone to non-demented subjects is associated with better visuospatial functioning and deterioration of verbal skills. In summary, gonadal hormones seem to modulate various aspects of mental functioning. If future studies prove this to be true, hormone replacement therapy should have a major impact on the physical and mental health of older people in the years to come.

Estrogen, serotonin, and mood disturbance: where is the therapeutic bridge?

A growing body of literature describes the effects of estrogen and other gonadal steroids on the central nervous system. The ability of estrogen to modulate serotonergic function, in particular, raises the possibility that sex steroids may play a role in the mechanisms associated with depression and its treatment. This review will focus on those aspects of the estrogen-serotonin interaction that relate to possible increased vulnerability to affective disorders and on hormonal treatments that may be clinically applicable to women. After a discussion of the potential relationship between estrogen and mood disorders across the female life cycle, a model is proposed in which differential sensitivity to mood disorders explains the differential response by some women to periods of normal hormonal changes. Possible serotonin receptor-mediated and intracellular mechanisms by which estrogen may exert its effects on mood are also reviewed. These are compared to putative mechanisms of standard antidepressant effect. Lastly, treatment studies in which estrogen has been used as 1) monotherapy for depression, 2) an augmentation strategy, or 3) a prophylactic intervention against recurrence of depression are reviewed.