Gender differences in response to differing antidepressant drug classes: two negative studies

Sex Differences in Stress Response: Classical Mechanisms and Beyond

Neuropsychiatric disorders, which are associated with stress hormone dysregulation, occur at different rates in men and women. Moreover, nowadays, preclinical and clinical evidence demonstrates that sex and gender can lead to differences in stress responses that predispose males and females to different expressions of similar pathologies. In this curated review, we focus on what is known about sex differences in classic mechanisms of stress response, such as glucocorticoid hormones and corticotrophin-releasing factor (CRF), which are components of the hypothalamicpituitary- adrenal (HPA) axis. Then, we present sex differences in neurotransmitter levels, such as serotonin, dopamine, glutamate and GABA, as well as indices of neurodegeneration, such as amyloid β and Tau. Gonadal hormone effects, such as estrogens and testosterone, are also discussed throughout the review. We also review in detail preclinical data investigating sex differences caused by recentlyrecognized regulators of stress and disease, such as the immune system, genetic and epigenetic mechanisms, as well neurosteroids. Finally, we discuss how understanding sex differences in stress responses, as well as in pharmacology, can be leveraged into novel, more efficacious therapeutics for all. Based on the supporting evidence, it is obvious that incorporating sex as a biological variable into preclinical research is imperative for the understanding and treatment of stress-related neuropsychiatric disorders, such as depression, anxiety and Alzheimer's disease.

Sex Differences in Depression and Anxiety

Depression and anxiety disorders carry a tremendous worldwide burden and emerge as a significant cause of disability among western societies. Both disorders are known to disproportionally affect women, as they are twice more likely to be diagnosed and moreover, they are also prone to suffer from female-specific mood disorders. Importantly, the prevalence of these affective disorders has notably risen after the COVID pandemic, especially in women. In this chapter, we describe factors that are possibly contributing to the expression of such sex differences in depression and anxiety. For this, we overview the effect of transcriptomic and genetic factors, the immune system, neuroendocrine aspects, and cognition. Furthermore, we also provide evidence of sex differences in antidepressant response and their causes. Finally, we emphasize the importance to consider sex as a biological variable in preclinical and clinical research, which may facilitate the discovery and development of new and more efficacious antidepressant and anxiolytic pharmacotherapies for both women and men.

Sex-Related Differences in Pharmacological Response to CNS Drugs: A Narrative Review

In the last decades, both animal and human studies have neglected female subjects with the aim of evading a theorized intricacy of feminine hormonal status. However, clinical experience proves that pharmacological response may vary between the two sexes since pathophysiological dissimilarities between men and women significantly influence the pharmacokinetics and pharmacodynamics of drugs. Sex-related differences in central nervous system (CNS) medication are particularly challenging to assess due to the complexity of disease manifestation, drugs’ intricate mechanisms of action, and lack of trustworthy means of evaluating the clinical response to medication. Although many studies showed contrary results, it appears to be a general tendency towards a certain sex-related difference in each pharmacological class. Broadly, opioids seem to produce better analgesia in women especially when they are administered for a prolonged period of time. On the other hand, respiratory and gastrointestinal adverse drug reactions (ADRs) following morphine therapy are more prevalent among female patients. Regarding antidepressants, studies suggest that males might respond better to tricyclic antidepressants (TCAs), whereas females prefer selective serotonin reuptake inhibitors (SSRI), probably due to their tolerance to particular ADRs. In general, studies missed spotting any significant sex-related differences in the therapeutic effect of antiepileptic drugs (AED), but ADRs have sex variations in conjunction with sex hormones’ metabolism. On the subject of antipsychotic therapy, women appear to have a superior response to this pharmacological class, although there are also studies claiming the opposite. However, it seems that reported sex-related differences regarding ADRs are steadier: women are more at risk of developing various side effects, such as metabolic dysfunctions, cardiovascular disorders, and hyperprolactinemia. Taking all of the above into account, it seems that response to CNS drugs might be occasionally influenced by sex as a biological variable. Nonetheless, although for each pharmacological class, studies generally converge to a certain pattern, opposite outcomes are standing in the way of a clear consensus. Hence, the fact that so many studies are yielding conflicting results emphasizes once again the need to address sex-related differences in pharmacological response to drugs.

Sex differences in depressive symptoms and tolerability after treatment with selective serotonin reuptake inhibitor antidepressants: Secondary analyses of the GENPOD trial

BACKGROUND

Differences in serotonergic neurotransmission could lead to sex differences in depressive symptoms and tolerability after treatment with selective serotonin reuptake inhibitors (SSRIs).

AIMS

We investigated whether women have greater reductions in depressive symptoms than men after treatment with an SSRI (citalopram) compared with a noradrenaline reuptake inhibitor (reboxetine) control, and after antidepressant treatment irrespective of class. We also investigated tolerability and the influence of menopausal status.

METHODS

Secondary analyses of the GENPOD (GENetic and clinical Predictors Of treatment response in Depression) trial. Six hundred and one people with depression were recruited from UK primary care and randomized to citalopram or reboxetine. Beck Depression Inventory (BDI-II) score at 6 weeks was the primary outcome. Secondary outcomes included BDI-II score at 12 weeks, and physical symptoms and treatment discontinuation. We calculated main effects and interaction terms using linear and logistic regression models.

RESULTS

There was no evidence that women experienced greater reductions in depressive symptoms than men when treated with citalopram compared with reboxetine. We also found no evidence of sex differences at six or 12 weeks (irrespective of antidepressant class): men scored -0.31 (95% confidence interval (CI) -2.23 to 1.62) BDI-II points lower than women at six weeks and -0.44 (95% CI -2.62 to 1.74) points lower at 12 weeks. There was no evidence of sex differences in physical symptoms or treatment discontinuation and no evidence for an influence of menopausal status.

CONCLUSION

Citalopram was not more effective in women compared with men and there was no difference in tolerability. Women and men had similar prognosis after SSRI treatment and similar prognosis regardless of antidepressant class. Findings were unaltered by menopausal status.

Gender differences in treatment with antidepressants during first weeks of a sick-leave spell due to depressive episode

Background

The incidence of depression is higher in women; women are more often on sick leave due to depression, and more women than men use antidepressants. The objective of this study was to explore possible gender differences in buying prescribed antidepressants during the first 21 days of a new sick-leave spell due to depressive episode.

Methods

Included were all individuals living in Sweden in working age (18–64 years old) who in 2010 or 2011 began a new sick-leave spell due to depressive episode (ICD-10 F32) lasting at least 21 days (n = 44 863). Register data on sociodemographics, morbidity and dispensed prescription medication were used to investigate associations between gender and buying prescribed antidepressants in the total group and in subgroups, using multiple logistic regression models.

Results

The study population consisted of 69.5% women. Within the first 21 days of the sick-leave spell, 48.0% of the men and 42.1% of the women had dispensed prescribed antidepressants. In the adjusted multiple logistic regression model, men had an odds ratio of 1.28 (95% confidence interval 1.23–1.33) as compared with women, for buying prescribed antidepressants.

Conclusions

In this nationwide register study, nearly half of the women and men on sick leave with depressive episode bought prescribed antidepressants during the first three weeks of the sick-leave spell. In the adjusted models, men were more likely to do this. Further studies are needed to elucidate the reasons for this gender difference.

Functional Dyspepsia: A Narrative Review With a Focus on Sex-Gender Differences

Functional dyspepsia (FD) is among the most common gastrointestinal disorders affecting quality of life (QoL). As it frequently occurs in women than in men the comparison of various aspects including prevalence, clinical manifestations, and QoL in FD between women and men is very important for understanding the disease distribution and burden, evaluating treatment options, developing new drugs, and allocating medical resources. However, little is known about sex or gender differences among patients with FD. In spite of limited studies, consistent points are that FD occurs more often in women than in men and there are several symptom differences between men and women with FD. In addition, women with FD tend to have lower QoL than men with FD. Similarly, the pathophysiology of FD likely to vary depending on gender. Furthermore, a sex-gender-oriented approach in healthcare system could enhance understanding heterogeneous patients suffering from FD. Due to the sex-gender differences in physiological and psychological factors, treatment strategies should differ between women and men with FD. In conclusion, an individualized and multicomponent approach that considers sex and gender issues might improve FD treatment and improve patient Qol, especially for women.

Guidelines for the evaluation and treatment of perimenopausal depression: summary and recommendations

There is a new appreciation of the perimenopause - defined as the early and late menopause transition stages as well as the early postmenopause - as a window of vulnerability for the development of both depressive symptoms and major depressive episodes. However, clinical recommendations on how to identify, characterize and treat clinical depression are lacking. To address this gap, an expert panel was convened to systematically review the published literature and develop guidelines on the evaluation and management of perimenopausal depression. The areas addressed included: 1) epidemiology; 2) clinical presentation; 3) therapeutic effects of antidepressants; 4) effects of hormone therapy; and 5) efficacy of other therapies (eg, psychotherapy, exercise, and natural health products). Overall, evidence generally suggests that most midlife women who experience a major depressive episode during the perimenopause have experienced a prior episode of depression. Midlife depression presents with classic depressive symptoms commonly in combination with menopause symptoms (ie, vasomotor symptoms, sleep disturbance), and psychosocial challenges. Menopause symptoms complicate, co-occur, and overlap with the presentation of depression. Diagnosis involves identification of menopausal stage, assessment of co-occurring psychiatric and menopause symptoms, appreciation of the psychosocial factors common in midlife, differential diagnoses, and the use of validated screening instruments. Proven therapeutic options for depression (ie, antidepressants, psychotherapy) are the front-line treatments for perimenopausal depression. Although estrogen therapy is not approved to treat perimenopausal depression, there is evidence that it has antidepressant effects in perimenopausal women, particularly those with concomitant vasomotor symptoms. Data on estrogen plus progestin are sparse and inconclusive.

Gender differences in healthcare management of depression: aspects of sick leave and treatment with psychoactive drugs in a Swedish setting

Purpose: To investigate whether women and men diagnosed with depressive disorder were managed equally in terms of being sick-leave certified and being prescribed psychoactive drugs. Materials and methods: Data from all patients diagnosed with depression during 2010-2015 in Uppsala county, Sweden (n = 19 448) were used to investigate associations between gender and issued sick-leave certificate, prescriptions of anti-depressants, anxiolytics, hypnotics and sedatives, and cognitive behavioral psychotherapy referrals, at different time points up till 180 days after diagnosis. Results: At diagnosis date, 50.1% were prescribed antidepressants; 14.2% anxiolytics; 13.3% hypnotics or sedatives. Corresponding proportion regarding issue of sick-leave certificate among working aged (18-64 years) was 16.6%. Men had higher odds than women of being prescribed antidepressants (OR 1.16; 95% CI 1.09-1.24); anxiolytics (1.10; 95% CI 1.02-1.21), hypnotics and sedatives (OR 1.09; 95% CI 1.00-1.19) and lower odds (among those aged 18-64 years) of being sick-leave certified (OR 0.90; 95% CI 0.82-0.98) in adjusted regression models. There were subtle changes in ORs for outcomes at 3- and 6-month follow-up periods. Conclusions: Men had somewhat higher odds of being prescribed psychoactive drugs and slightly lower odds of being sick-leave certified as compared to women at date when diagnosed with depression. The absolute differences were, however, small and the overall conclusion is that women and men with current diagnosed depressive episode/recurrent depressive disorder are generally managed likewise regarding sick leave and psychoactive treatment.

How to choose an antidepressant medication

OBJECTIVE

We consider how to choose an antidepressant (AD) medication for the treatment of clinical depression.

METHOD

A narrative review was undertaken addressing antidepressant 'choice' considering a range of parameters either weighted by patients and clinicians or suggested in the scientific literature. Findings were synthesised and incorporated with clinical experience into a model to assist AD choice.

RESULTS

Efficacy studies comparing ADs offer indicative guidance, while precision psychiatry prediction based on genetics, developmental trauma, neuroimaging, behavioural and cognitive biomarkers, currently has limited clinical utility. Our model offers guidance for AD choice by assessing first for the presence of a depressive subtype or symptom cluster and matching choice of AD class accordingly. Failing this, an AD can be chosen based on depression severity. Within-class choice can be determined by reference to personality style, patient preference, medical or psychiatric comorbidities and side-effect profile.

CONCLUSION

Clarification of AD choice would occur if medications are trialled in specific depressive subtypes rather than using the generic diagnosis of major depressive disorder (MDD). Such 'top-down' methods could be enhanced by 'bottom-up' studies to classify individuals according to symptom clusters and biomarkers with AD efficacy tested in these categories. Both methods could be utilised for personalised AD choice.

Sex differences in depression: Insights from clinical and preclinical studies

Depression represents a global mental health concern, and disproportionally affects women as they are twice more likely to be diagnosed than men. In this review, we provide a summary of evidence to support the notion that differences in depression between men and women span multiple facets of the disease, including epidemiology, symptomology, treatment, and pathophysiology. Through a lens of biological sex, we overview depression-related transcriptional patterns, changes in neuroanatomy and neuroplasticity, and immune signatures. We acknowledge the unique physiological and behavioral demands of pregnancy and motherhood by devoting special attention to depression occurring in the peripartum period. Specifically, we discuss issues surrounding the presentation, time course, treatment, and neurobiology of peripartum depression. We write this review with the intention of highlighting the encouraging advancements in our understanding of sex differences in depression, while underscoring the gaps that remain. A more systematic consideration of biological sex as a variable in depression research will be critical in the discovery and development of pharmacotherapies that are efficacious for both men and women.

Sex Differences in Antidepressant Effect of Sertraline in Transgenic Mouse Models

The main purpose of this study is to explore sex differences in the antidepressant effect of sertraline in genetic knockout or overexpression estrogen-synthesizing enzyme aromatase (Ar) gene mouse models in the forced swim test (FST). Our results demonstrated a significant reduction of depression-like behavior in the mice with overexpression of brain aromatase (Thy1-Ar) compared to sex- and age-matched Ar^+/− mice or wild type control mice. Using HPLC analysis, we also found an association between the brain estrogen-related antidepressive behavior and the regulation of serotonin (5-HT) system. Interestingly, a single dose administration of sertraline (10 mg/kg, i.p.) induced reduction of immobility time was found in all genotypes, except male Ar^+/− mice. While the underlying mechanisms of sex-specific response on antidepressive effect of sertraline remain to be investigated, our data showed that female mice appear to be more sensitive to sertraline-induced changes of 5-HT system than male mice in the prefrontal cortex (PFC) and the hippocampus (HPC). Further investigation of sex-specific effect of brain estrogen on antidepressant is needed.

Women's Psychiatry

Brain disorders and mental diseases, in particular, are common and considered as a top global health challenge for the twenty-first century. Interestingly, women suffer more frequently from mental disorders than men. Moreover, women may respond to psychotropic drugs differently than men, and, through their lifespan, they endure sex-orientated social stressors. In this chapter, we present how women may differ in the development and manifestation of mental health issues and how they differ from men in pharmacokinetics and pharmacodynamics. We discuss issues in clinical trials regarding women participation, issues in the use of psychotropic medications in pregnancy, and challenges that psychiatry faces as a result of the wider use of contraceptives, of childbearing at older age, and of menopause. Such issues, among others, demand further women-oriented psychiatric research that can improve the care for women during the course of their lives. Indeed, despite all these known sex differences, psychiatry for both men and women patients uses the same approach. Thereby, a modified paradigm for women's psychiatry, which takes into account all these differences, emerges as a necessity, and psychiatric research should take more vigorously into account sex differences.

[Gender Difference in Functional Gastrointestinal Disorders]

Functional gastrointestinal diseases (FGIDs) are known to be influenced more by a lowering of the quality of life, such as mental health and sleep quality, compared to organic diseases. Genetic, microbiological, molecular biological, and social environmental factors are involved in the pathophysiology of FGIDs. In particular, mental factors, such as depression and anxiety, play a major role in the development of FGIDs. The prevalence of most FGIDs is higher in women. Gender needs to be analyzed in patients with FGIDs because it can have a great influence on the onset of FGIDs. Because there are differences in the treatment response according to gender, further research in the development of therapeutic drugs considering this gender difference will be needed, and ultimately it will be possible to lower the prevalence of FGIDs and improve the quality of life of patients.

The impact of sex as a biological variable in the search for novel antidepressants

A roadblock to successful treatment for anxiety and depression is the high proportion of individuals that do not respond to existing treatments. Different underlying neurobiological mechanisms may drive similar symptoms, so a more personalized approach to treatment could be more successful. There is increasing evidence that sex is an important biological variable modulating efficacy of antidepressants and anxiolytics. We review evidence for sex-specific effects of traditional monoamine based antidepressants and newer pharmaceuticals targeting kappa opioid receptors (KOR), oxytocin receptors (OTR), and N-methyl-D-aspartate receptors (ketamine). In some cases, similar behavioral effects are observed in both sexes while in other cases strong sex-specific effects are observed. Most intriguing are cases such as ketamine which has similar behavioral effects in males and females, perhaps through sex-specific neurobiological mechanisms. These results show how essential it is to include both males and females in both clinical and preclinical evaluations of novel antidepressants and anxiolytics.

Preclinical sex differences in depression and antidepressant response: Implications for clinical research

Women suffer from depression and anxiety disorders more often than men, and as a result they receive antidepressants to a greater extent. Sex differences in antidepressant response in humans have been modestly studied, and results have been controversial. At the same time, preclinical studies on animal models of depression and antidepressant response have provided insights with regard to sex differences that could be useful for the design and interpretation of future clinical trials. This Mini-Review discusses such sex-differentiated findings with regard to the presentation of depression, endophenotypes, and antidepressant response. In particular, men and women differ in symptomatology of depression, and animal models of depression have revealed sex differences in behavioral indices. However, although in experimental studies behavioral indices and models are adjusted to identify sex differences properly, this is not the case in the use of depression rating scales in clinical studies. Accordingly, preclinical studies highlight the importance of sex differences at the baseline behavioral response and the underlying mechanisms that often converge after antidepressant treatment. This is also a neglected issue in human studies. Finally, preclinical research suggests that, in the quest for potential biomarkers for depression, sex should be an important factor to consider. Careful consideration of sex differences in preclinical research could facilitate and ameliorate the design and quality of clinical studies for disease biomarkers and novel fast-acting antidepressants that are so essential for both men and women suffering from depression. © 2016 Wiley Periodicals, Inc.

Sex differences in the psychopharmacological treatment of depression

Although a number of studies have observed that females respond better to serotonergic antidepressants than males and that postmenopausal females have a diminished response to antidepressants compared with younger females, there are also studies that conflict with both of these findings, making any generalizations regarding sex differences difficult to make. Sex variance in antidepressant efficacy and pharmacokinetics profiles have been attributed to sex-based physiological differences, behavioral differences, related disorders, and sex-specific conditions, including pregnancy and menopause. This paper will review the history and current research on sex effects of antidepressant treatment.

Lurasidone in post-menopausal females with major depressive disorder with mixed features: Post-hoc analysis of a placebo-controlled trial

BACKGROUND

Several studies have found that depressed, post-menopausal females may respond differently to antidepressants compared to pre-menopausal females. The atypical antipsychotic lurasidone, whose mechanism of action differs from SSRIs and other standard antidepressants, was shown in a 6-week randomized, flexible-dose, placebo-controlled study (n=209), to be effective in treating major depressive disorder (MDD) with mixed features (subthreshold hypomanic symptoms). This post-hoc analysis assessed the efficacy of lurasidone in this study by menopausal status.

METHODS

The main outcome measure for this post-hoc analysis was change in MADRS score from baseline to week 6 endpoint for two lurasidone-treated subgroups: presumptive pre-menopausal (<52years) and presumptive post-menopausal (≥52years) patients, compared to placebo treatment, using a mixed-model for repeated-measures analysis, and calculation of the effect size for each subgroup. Additional efficacy assessments included the CGI-S, HAM-A and YMRS. An exploratory analysis was also conducted removing presumptive peri-menopausal women (ages 45-51years) to allow for clearer definition of pre- and post-menopausal status.

RESULTS

A total of 56 lurasidone-treated and 47 placebo-treated pre-menopausal females, and 17 lurasidone-treated and 25 placebo-treated post-menopausal females were available from the larger study for comparison on key outcome measures. The pre- and post-menopausal subgroups had similar demographic and clinical characteristics at study baseline (other than age), including number of past major depressive episodes as well as depressive and manic symptom severity. Mean daily lurasidone dose was similar for each subgroup during the study. Both the primary and exploratory analyses showed that both lurasidone-treated post-menopausal and pre-menopausal females responded significantly compared to placebo (p=0.016 or less) on the MADRS, and that post-menopausal patients had a numerically larger response (effect size=0.96) than pre-menopausal patients (effect size=0.64). All other secondary outcome measures for lurasidone compared with placebo treatment were significant (p=0.045 or less) for both subgroups.

CONCLUSIONS

In this post-hoc analysis, lurasidone was found to be effective in treating post-menopausal MDD patients with mixed features (subthreshold hypomanic symptoms).

Obesity and Its Potential Effects on Antidepressant Treatment Outcomes in Patients with Depressive Disorders: A Literature Review

Accumulating evidence regarding clinical, neurobiological, genetic, and environmental factors suggests a bidirectional link between obesity and depressive disorders. Although a few studies have investigated the link between obesity/excess body weight and the response to antidepressants in depressive disorders, the effect of weight on treatment response remains poorly understood. In this review, we summarized recent data regarding the relationship between the response to antidepressants and obesity/excess body weight in clinical studies of patients with depressive disorders. Although several studies indicated an association between obesity/excess body weight and poor antidepressant responses, it is difficult to draw definitive conclusions due to the variability of subject composition and methodological differences among studies. Especially, differences in sex, age and menopausal status, depressive symptom subtypes, and antidepressants administered may have caused inconsistencies in the results among studies. The relationship between obesity/excess body weight and antidepressant responses should be investigated further in high-powered studies addressing the differential effects on subject characteristics and treatment. Moreover, future research should focus on the roles of mediating factors, such as inflammatory markers and neurocognitive performance, which may alter the antidepressant treatment outcome in patients with comorbid obesity and depressive disorder.

Aberrant CYP2D6 metabolizer phenotypes do not show increased frequency in patients undergoing ECT after antidepressant therapy

We investigated the accumulation of aberrant CYP2D6 genotypes and predicted metabolizer phenotypes (ultrarapid metabolizer, intermediate metabolizer and poor metabolizer) potentially affecting the antidepressant treatment response in depressive patients indicated for electroconvulsive therapy (ECT) compared with patients with a single episode of depression. Seventy-six Dutch White patients with unipolar or bipolar treatment-resistant depression who underwent ECT were genotyped using the Amplichip CYP450 Test for CYP2D6. Two hundred and eight patients with a single episode of unipolar or bipolar depression were used as controls. No difference was observed in the prevalence of CYP2D6 phenotypes (poor metabolizer, intermediate metabolizer, extensive metabolizer and ultrarapid metabolizer) between the ECT and the control patients (5.3, 38.7, 56.0 and 0.0% vs. 6.4, 51.0, 42.6 and 0.0%, respectively). The types of depression (odds ratio = 0.33, P = 0.018) and age (odds ratio = 1.55 for a 10-year increase, P < 0.001), but not CYP2D6 phenotype or activity score were associated with the response to antidepressant treatment. In conclusion, preemptive genotyping for CYP2D6 currently appears to have no clinical implications in treatment-resistant depressive patients indicated for ECT.

A pooled analysis of the efficacy of desvenlafaxine for the treatment of major depressive disorder in perimenopausal and postmenopausal women

BACKGROUND

Few studies in the literature have examined the efficacy of antidepressant drugs in perimenopausal and postmenopausal women. The objective of the current study was to assess the efficacy of desvenlafaxine (administered as desvenlafaxine succinate) separately in perimenopausal and postmenopausal women with major depressive disorder (MDD).

METHODS

Data were pooled from two double-blind, placebo-controlled clinical trials enrolling perimenopausal and postmenopausal women (40-70 years old) diagnosed with MDD. Patients were randomly assigned to receive desvenlafaxine 100 to 200 mg/day or placebo (8 weeks) or desvenlafaxine 50 mg/day or placebo (10 weeks). The primary efficacy end point for each trial was change from baseline in Hamilton Rating Scale for Depression (HAM-D17) total score at week 8. Secondary end points included change from baseline in Sheehan Disability Scale (SDS) and Menopause Rating Scale (MRS) scores. Changes from baseline in continuous variables were analyzed using analysis of covariance with treatment, region, and baseline in the model. All treatment comparisons were carried out separately in perimenopausal or postmenopausal women, in individual studies, and in the pooled population, adjusting for menopausal status and study.

RESULTS

A total of 798 patients were included in the full analysis set (perimenopausal, n=252; postmenopausal, n=546). Desvenlafaxine significantly reduced HAM-D17 total scores versus placebo at week 8 in both perimenopausal (-10.3 vs. -6.5; p<0.001) and postmenopausal women (-10.1 vs. -7.6; p<0.001). Significant improvements in SDS and MRS total scores were also observed for desvenlafaxine versus placebo in perimenopausal (p ≤ 0.024) and postmenopausal women (p ≤ 0.009). A significant treatment by menopausal status interaction was observed for SDS only (p=0.036).

CONCLUSIONS

Desvenlafaxine demonstrated antidepressant efficacy in both perimenopausal and postmenopausal subgroups of women with MDD.

DISCLAIMER

In September 2011, Pfizer received a Complete Response Letter from the United States Food and Drug Administration on its application for approval to market desvenlafaxine for the treatment of moderate to severe vasomotor symptoms associated with menopause. The Complete Response Letter states that the data included in the application are not sufficient to establish an acceptable risk/benefit profile for the treatment of vasomotor symptoms in the general population of postmenopausal women, and therefore desvenlafaxine is not approved for the treatment of vasomotor symptoms in the United States at this time. This decision does not impact desvenlafaxine's approval for the treatment of MDD in adults.

Sex differences in the pharmacokinetics of antidepressants: influence of female sex hormones and oral contraceptives

Women are twice as likely to develop depression as men. Moreover, the symptoms they experience also show sex differences: women tend to develop depression at an earlier age and show more severe symptoms than men. Likewise, the response to antidepressant pharmacotherapy appears to have sex differences. These differences can partially be explained by differences in pharmacokinetic properties (i.e., absorption, distribution, metabolism, and excretion) of drugs in males and females. More recent research has shown that sex hormones may influence all these previously named pharmacokinetic processes. As concentrations of sex hormones vary throughout the female lifespan, these hormonal variations can have effects on therapeutic responses to antidepressants as well as the occurrence of adverse events. The purpose of this paper is therefore to review the literature reporting on the effects of female sex hormones on the pharmacokinetics of antidepressants and to discuss and evaluate the implications of changes in levels of sex hormones throughout life for the treatment of depression.

Influence of sex and stress exposure across the lifespan on endophenotypes of depression: focus on behavior, glucocorticoids, and hippocampus

Sex differences exist in vulnerability, symptoms, and treatment of many neuropsychiatric disorders. In this review, we discuss both preclinical and clinical research that investigates how sex influences depression endophenotypes at the behavioral, neuroendocrine, and neural levels across the lifespan. Chronic exposure to stress is a risk factor for depression and we discuss how stress during the prenatal, postnatal, and adolescent periods differentially affects males and females depending on the method of stress and metric examined. Given that the integrity of the hippocampus is compromised in depression, we specifically focus on sex differences in how hippocampal plasticity is affected by stress and depression across the lifespan. In addition, we examine how female physiology predisposes depression in adulthood, specifically in postpartum and perimenopausal periods. Finally, we discuss the underrepresentation of women in both preclinical and clinical research and how this limits our understanding of sex differences in vulnerability, presentation, and treatment of depression.

Gender differences in genetic mouse models evaluated for depressive-like and antidepressant behavior

Depression is a mental disease that affects complex cognitive and emotional functions. It is believed that depression is twice as prevalent in women as in men. This phenomenon may influence the response to various antidepressant therapies, and these differences are still underestimated in clinical treatment. Nevertheless, most of the current findings are based on studies on male animal models, and relatively few of these studies take possible gender differences into consideration. Advancements in genetic engineering over the last two decades have introduced many transgenic lines that have been screened to study the pathomechanisms of depression. In this mini-review, we provide a compendious list of genetically altered mice that underwent tests for depressive-like or antidepressant behavior and determine if and how the gender factor was analyzed in their evaluation. Furthermore, we compile the gender differences in response to antidepressant treatment. On the basis of these analyses, we conclude that in many cases, gender variability is neglected or not taken into consideration in the presented results. We note the necessity of discussing this issue in the phenotypic characterization of transgenic mice, which seems to be particularly important while modeling mental diseases.

Sex, hormones and neurogenesis in the hippocampus: hormonal modulation of neurogenesis and potential functional implications

The hippocampus is an area of the brain that undergoes dramatic plasticity in response to experience and hormone exposure. The hippocampus retains the ability to produce new neurones in most mammalian species and is a structure that is targeted in a number of neurodegenerative and neuropsychiatric diseases, many of which are influenced by both sex and sex hormone exposure. Intriguingly, gonadal and adrenal hormones affect the structure and function of the hippocampus differently in males and females. Adult neurogenesis in the hippocampus is regulated by both gonadal and adrenal hormones in a sex- and experience-dependent way. Sex differences in the effects of steroid hormones to modulate hippocampal plasticity should not be completely unexpected because the physiology of males and females is different, with the most notable difference being that females gestate and nurse the offspring. Furthermore, reproductive experience (i.e. pregnancy and mothering) results in permanent changes to the maternal brain, including the hippocampus. This review outlines the ability of gonadal and stress hormones to modulate multiple aspects of neurogenesis (cell proliferation and cell survival) in both male and female rodents. The function of adult neurogenesis in the hippocampus is linked to spatial memory and depression, and the present review provides early evidence of the functional links between the hormonal modulation of neurogenesis that may contribute to the regulation of cognition and stress.

Increased hippocampal neurogenesis and p21 expression in depression: dependent on antidepressants, sex, age, and antipsychotic exposure

The mammalian hippocampus continues to generate new neurons throughout life. The function of adult-generated neurons remains controversial, but adult neurogenesis in the hippocampus is related to depression. Studies show that neurogenesis in the hippocampus is regulated by antidepressants in both humans and rodents, but no studies have examined the effects of age, sex, or antipsychotic exposure on the relationship between depression, antidepressant exposure, and hippocampal neurogenesis in humans. Hippocampal sections were obtained from the Stanley Medical Research Institute and were immunohistochemically labeled for the immature neuron marker doublecortin and the cell cycle arrest marker p21. We compared the number of cells in the granule cell layer and subgranular zone that expressed these proteins in brains from control subjects (n=12), patients with major depressive disorder (MDD) without psychotic symptoms (n=12), and patients with MDD and psychotic symptoms (n=12). We show here that the density of doublecortin/NeuN expression was increased in MDD patients compared with controls and MDD patients with psychosis, with the effect greater in women. Further, we show that older depressed patients without psychosis had higher levels of p21/NeuN expression and that depressed individuals prescribed antidepressants had higher levels of p21/NeuN expression, but only in older women. We show for the first time that changes in neurogenesis due to prescribed antidepressants or depression are dependent on age, sex, and the presence of antipsychotics or psychotic symptoms.

Pharmacokinetics and pharmacodynamics of psychotropic drugs: effect of sex

Data on the specific effects of sex on pharmacokinetics, as well as tolerability, safety, and efficacy of psychotropic medications are still meager, mainly because only recently sex-related issues have attracted a certain degree of interest within the pharmacological domain. Therefore, with the present study, we aimed to provide a comprehensive review of the literature on this topic, through careful MEDLINE and PubMed searches of the years 1990-2012. Generally, data on pharmacokinetics are more consistent and numerous than those on pharmacodynamics. Sex-related differences have been reported for several parameters that influence pharmacokinetics, such as gastric acidity, intestinal motility, body weight and composition, blood volume, liver enzymes (mainly the cytochrome P450), or renal excretion, which may alter plasma drug levels. Sex-related peculiarities may also account for a different sensitivity of men and women to side effects and toxicity of psychotropic drugs. Further, some differences in drug response, mainly to antipsychotics and antidepressants, have been described. Further studies are, however, necessary to explore more thoroughly the impact of sex on the pharmacokinetics and pharmacodynamics of psychotropic drugs, in order to reach the most appropriate and tailored prescription for each patient.

Course of mental symptoms in patients with stress-related exhaustion: does sex or age make a difference?

BACKGROUND

Long-term sick leave due to mental health problems, especially among women, is a substantial problem in many countries, and a major reason for this is thought to be psychosocial stress. The recovery period of different patient groups with stress-related mental health problems can differ considerably. We have studied the course of mental health symptoms during 18 months of multimodal treatment in relation to sex and age in a group of patients with stress-related exhaustion.

METHODS

The study group includes 232 patients (68% women) referred to a stress clinic and who fulfilled the criteria for Exhaustion Disorder (ED). The majority also fulfilled diagnostic criteria for depression and/or anxiety; this was similar among women and men. Symptoms were assessed at baseline, three, six, 12 and 18 months by the Shirom-Melamed Burnout Questionnaire (SMBQ) and the Hospital Anxiety and Depression scale (HAD). A total SMBQ mean score of ≥ 4 was used to indicate clinical burnout, which correlates well with the clinical diagnosis of ED.

RESULTS

There were no statistically significant differences between women and men or between young and old patients in the self-reported symptoms at baseline. The proportion that had high burnout scores decreased over time, but one-third still had symptoms of clinical burnout after 18 months. Symptoms indicating probable depression or anxiety (present in 34% and 65% of the patients at baseline, respectively) declined more rapidly, in most cases within the first three months, and were present only in one out of 10 after 18 months. The course of illness was not related to sex or age. The duration of symptoms before seeking health care, but not the level of education or co-morbid depression, was a predictor of recovery from symptoms of burnout after 18 months.

CONCLUSIONS

The course of mental illness in patients seeking specialist care for stress-related exhaustion was not related to sex or age. The burden of mental symptoms is high and similar for men and women, and at the 18 month follow-up, one-third of the study group still showed symptoms of burnout. A long duration of symptoms before consultation was associated with a prolonged time of recovery, which underlines the importance of early detection of stress-related symptoms.

Interaction between two HTR2A polymorphisms and gender is associated with treatment response in MDD

The 5HT2A receptor gene (HTR2A) polymorphisms rs7997012 and rs6311 have in some earlier studies been associated with serotonin selective reuptake inhibitor (SSRI) treatment response in major depressive disorder (MDD), but the findings are inconsistent. The aim of the present study was to test for an association between two HTR2A polymorphisms (rs7997012 and rs6311), their interaction and the Montgomery and Åsberg Depression Rating Scale (MADRS) score change after ECT or SSRI treatment. The total number of patients was 218. All were treated in outpatient care. Of these, 119 subjects had treatment-resistant MDD and were treated with ECT and 99 were depressive patients treated with SSRI. Treatment response was assessed by MADRS. Patients scoring <8 on post-treatment MADRS were considered remitters. Neither rs7997012 nor rs6311 HTR2A polymorphism was significantly associated with MADRS score change alone, but the interaction between them and gender explained 14% of the variance in MADRS score change. The finding suggests an association between MADRS score change and interaction of HTR2A polymorphisms, rs7997012 and rs6311 and gender.

Gender differences in antidepressant drug response

Epidemiological studies suggest there are considerable differences in the prevalence and presentation of depression in men and women. Women are more than twice as likely to be diagnosed with depression and may also report more atypical and anxiety symptoms than men. Men and women also differ in the metabolism and distribution of antidepressants and the presence of oestrogen in women of childbearing age may interfere with the mechanism of action of a number of antidepressants. These differences have led many researchers to question whether antidepressants are equally effective and tolerated in men and women. While some reports suggest that selective serotonin re-uptake inhibitors (SSRIs) are more effective and result in fewer adverse drug reactions in women than tricyclic antidepressants (TCAs), gender differences in antidepressant response remains a controversial topic. The potential effects of antidepressant exposure in utero and in breast milk further complicate treatment options for antenatal and postnatal depression. While some research suggests the SSRI paroxetine is teratogenic, further carefully designed naturalistic studies are required to fully evaluate these effects. Finally, response to antidepressants and the occurrence of adverse drug reactions is marked by inter-individual variability which may be in part due to genetic differences. Future studies should therefore consider genotypes of the mother, foetus and infant in antidepressant response.

The impact of gender on antidepressants

There is a large body of literature debating whether and how gender affects the metabolism, side-effect profile, and efficacy of antidepressants. Gender differences in antidepressant pharmacokinetics and efficacy profiles have been attributed to not only anatomic and physiological differences between the sexes, but also behavioral factors, comorbid disorders, and gender-specific conditions, such as pregnancy and menopause. Despite the large body of research on this topic, few definitive conclusions regarding effects of gender on antidepressant treatment exist, and much of this research is incomplete, contradictory, or not fully used to optimize the administration of antidepressants and the response to treatment. This chapter will review the latest research on gender-specific effects of antidepressant treatment, focusing on the overall, gender-related differences in efficacy, metabolism, and side-effect profile of antidepressants, and how these differences can be used to better optimize treatment of depression in a clinical setting.

Genetic variability in estrogen disposition: Potential clinical implications for neuropsychiatric disorders

Variability in the physiological levels of neuroactive estrogens is widely believed to play a role in predisposition to several disorders of the central nervous system. Local biosynthesis of estrogens in the brain as well as their circulating serum levels are known to contribute to this pool of neuroactive steroids. It has been well accepted that estrogens modulate neuronal functions by affecting genesis, differentiation, excitability, and degeneration of nerve cells. These actions of estrogens appear to be more prominent in females with higher concentrations and marked variability of circulating serum levels occurring over a woman's lifetime. However, our knowledge regarding the variability of neuroactive steroid levels is very limited. Furthermore, several studies have recently reported differences in the synchronization of circulating and neuronal levels of estradiol. In the absence of reliable circulating steroid levels, knowledge of genetic variability in estrogen disposition may play a determining factor in predicting altered susceptibility or severity of neuropsychiatric disorders in women. Over the past decade, several genetic variants have been linked to both differential serum estrogen levels and predisposition to diverse types of neuropsychiatric disorders in women. Polymorphisms in genes encoding estrogen-metabolizing enzymes as well as estrogen receptors may account for this phenotypic variability. In this review, we attempt to show the contribution of genetics in determining estrogenicity in females with a particular emphasis on the central nervous system. This knowledge will further provide a driving force for unearthing the novel field of "Estrogen Pharmacogenomics." © 2010 Wiley-Liss, Inc.

Sex-related differential response to clomipramine treatment in a rat model of depression

Research in affective disorders is often performed without considering sex differences, although women are predominantly affected. Consequently, the potential sex-dependent action of antidepressants remains elusive. We investigated whether Flinders sensitive line (FSL) of rats, a model of depression, would present sex-differentiated responses to antidepressant treatment. FSL and Sprague-Dawley rats were treated with clomipramine 10 mg/kg/day for 14 days. Subsequently, they were subjected to either a single session of the forced swim test or an estimation of serotonergic function in the prefrontal cortex, hippocampus, amygdala and hypothalamus. Male FSL displayed increased immobility duration, decreased active behaviours, increased serotonin tissue levels and a reduced serotonin turnover rate in most brain areas studied. Female FSL showed a distinct profile, consisting of decreased immobility latency, increased climbing duration, limited serotonergic deviations and no difference in the serotonin turnover rate in comparison with controls. Interestingly, despite baseline differences, clomipramine treatment reversed all relevant behavioural responses and increased the serotonin turnover rate in both sexes. However, the latter effect was remarkably more pronounced in females. It is concluded that, in this animal model of depression, chronic clomipramine treatment attenuated baseline sex differences in the phenotype while maintaining or intensifying the sex differentiation in the serotonergic endophenotype.

Does major depressive disorder change with age?

BACKGROUND

The authors used results from a 20-year, high-intensity follow-up to measure the influence of ageing, and of age at onset, on the long-term persistence of symptoms in major depressive disorder (MDD).

METHOD

Subjects who completed a 20-year series of semi-annual and then annual assessments with a stable diagnosis of MDD or schizo-affective disorder other than mainly schizophrenic (n=220) were divided according to their ages at intake into youngest (18-29 years), middle (30-44 years) and oldest (>45 years) groups. Depressive morbidity was quantified as the proportion of weeks spent in major depressive or schizo-affective episodes. General linear models then tested for effects of time and time x group interactions on these measures. Regression analyses compared the influence of age of onset and of current age.

RESULTS

Analyses revealed no significant time or group x time effects on the proportions of weeks in major depressive episodes in any of the three age groups. Earlier ages of onset were associated with greater symptom persistence, particularly in the youngest group. The proportions of weeks ill showed intra-individual stability over time that was most evident in the oldest group.

CONCLUSIONS

These results indicate that the persistence of depressive symptoms in MDD does not change as individuals move from their third to their fifth decade, from their fourth to their sixth decade, or from their sixth to their eighth decade. An early age of onset, rather than youth per se, is associated with greater morbidity over two decades.

BMI, sex, and antidepressant response

BACKGROUND

Investigators have examined potential mechanisms for the observed differences between men and women in antidepressant response. However, to date no studies have measured the impact of body mass index (BMI) on men's and women's response to selective serotonin re-uptake inhibitors or placebo.

METHODS

We evaluated the response to antidepressants and placebo of 274 non-obese (BMI<30) and obese (BMI>30) depressed outpatients participating in Phase II-IV clinical trials. After categorizing men and women into their respective BMI groups, we measured the amount of change each group experienced from baseline to the final visit using the HAM-D-17 and MADRS ratings scales.

RESULTS

Compared to women, men assigned to an antidepressant had a significantly lower mean total change on both the HAM-D-17 [non-obese, F(1,88)=5.292, p=0.024; obese, F(1,39)=7.040; p=0.012] and the MADRS [non-obese, F(1,66)=4.049, p=0.048; obese, F(1,27)=8.631, p=0.007]. In fact, obese men showed the smallest difference in antidepressant-placebo response. The results of the ANCOVAs indicated significant main effects of treatment (placebo vs. antidepressant), sex of the patient, and BMI category as well as a significant interaction between all three variables.

LIMITATIONS

Patients participating in clinical trials are not necessarily representative of the entire depressed population. In addition, our results include only SSRIs, not other antidepressants.

CONCLUSION

Compared to the rest of the depressed sample the subgroup of depressed obese men (n=40) showed little or no therapeutic benefit with SSRI antidepressants. Although our findings may have important clinical implications, replication and further research is warranted in order to understand their underlying mechanisms and their pertinence to dosing strategies.

Preliminary support for gender differences in response to fluoxetine for generalized anxiety disorder

Women have a higher prevalence of generalized anxiety disorder (GAD) than do men, but few studies have assessed gender differences in response to pharmacotherapy. In this study we examined gender as a correlate of response to 6 weeks of open, prospective fluoxetine treatment in 23 men and 22 women with a primary diagnosis of GAD. There was no difference by gender in age or prevalence of mood and anxiety comorbidity; however, GAD onset occurred at a significantly younger age in women compared with men. Despite a lack of difference in baseline severity measures, women had a significantly poorer response to fluoxetine as measured by both the Hamilton Anxiety Rating Scale (HAM-A) and Clinician Global Impression-Severity Scale (CGI-S). In multivariate analyses, there was a significant interaction between age of onset and gender: men with younger age of onset and women with older age of onset exhibited poorer response on the HAM-A. These data, though limited in sample size and by the post hoc nature of our analyses, offer preliminary support that women with GAD, particularly those with a later age of onset, may have a poorer response to the selective serotonin reuptake inhibitor (SSRI) fluoxetine. Larger placebo-controlled trials are needed to more definitively examine gender and treatment response in anxiety disorders.

Is functional dyspepsia of particular concern in women? A review of gender differences in epidemiology, pathophysiologic mechanisms, clinical presentation, and management

Dyspepsia is a remarkably common symptom in the general population. Although multiple definitions have been used to describe the symptom, the most common explanation is that of chronic or recurrent pain or discomfort (a subjective negative feeling that may be associated with early satiety, fullness, bloating, or nausea) centered in the upper abdomen. When a thorough evaluation of a dyspeptic patient fails to identify a cause for her symptoms, the label of nonulcer or functional dyspepsia is applied. Functional dyspepsia is a heterogeneous disorder characterized by relapsing and remitting symptoms. Treatment strategies should focus on alleviating the most bothersome symptom and can be based on the proposed underlying pathophysiology. The effect of gender on mechanisms of disease, symptom presentation, and treatment response is an area of increasing interest and study. As with other functional gastrointestinal disorders, there appear to be some gender-specific features of functional dyspepsia. Specifically, gender-related differences have been observed in some studies of both the prevalence of individual dyspepsia symptoms, and in gastric emptying and proximal gastric motor function. There also appear to be gender differences in the psychosocial realm, with dyspeptic women experiencing a lesser sense of well-being than dyspeptic men, as well as an association of an abuse history with functional dyspepsia. This review will highlight specific gender differences related to the symptom presentation, pathophysiology, and approach to treatment of functional dyspepsia, while noting where differences have not been found and where further investigation is warranted.

Different gender response to serotonergic and noradrenergic antidepressants. A comparative study of the efficacy of citalopram and reboxetine

BACKGROUND

It is well established that depressive disorders are more prevalent in women; however gender differences in the pharmacological response to antidepressants are not a consistent finding in all reports. It is considered that this discrepancy can be explained by the fact that in most clinical trials drug use for comparative purposes is not completely different. In this study gender differences in antidepressant response with citalopram (CTP), a selective serotonin reuptake inhibitor and reboxetine (RBX), a selective noradrenaline reuptake inhibitor were evaluated in a group of young men and premenopausal women.

METHOD

Eighty-six depressed patients 18 to 40 years old participated in an 8-week double-blind clinical trial. Subjects were divided in four groups according to sex and treatment assignation: females treated with CTP (n = 25) or RBX (n = 23), and males treated with CTP (n = 19) or RBX (n = 19). Response was determined using HDRS and BDI.

RESULTS

ANOVA analysis considering change in HDRS scores from baseline to last evaluation found a significant interaction between gender and type of treatment. Females treated with CTP showed a significantly greater response than females treated with RBX, while in men no differences were observed for both drugs.

LIMITATIONS

Replication using larger sample size and longer treatment periods is required.

CONCLUSIONS

These results support previous findings which show that premenopausal women respond better than men to serotonergic antidepressants. They also support that a plausible interaction between gonadal hormones and serotonin may explain gender differences in antidepressant response.

Gender differences in response to antidepressant treatment prescribed in primary care. Does menopause make a difference?

BACKGROUND

Epidemiological surveys have consistently reported that the prevalence of major depression in women is almost twice as high as it is in men. While it seems that no major gender differences have been observed in the severity and symptomatology of depression, results regarding differences in antidepressant treatment response are controversial, especially when considering menopause in treatment response.

METHODS

A total of 242 women (95 in their menopause), and 59 men beginning antidepressant treatment with a selective serotonin reuptake inhibitor (SSRI; Citalopram, Fluoxetine, Paroxetine or Sertraline) from 16 primary care (PC) centres were followed up during 6 months. Menopause effect and gender differences in antidepressant treatment response were evaluated. Additionally, severity and symptomatology of depression were compared among genders.

RESULTS

Overall results suggest that menopause is related to a worse treatment response and to a poorer self-evaluation of global health status. No gender differences were observed in treatment response, depression severity, and symptomatology.

LIMITATIONS

Since our sample included PC participants, a wide spectrum of depression severity was considered. Additionally, menopause was assessed by means of participants' self-report.

CONCLUSIONS

Menopause seems to negatively affect SSRI treatment response of depressed women treated in PC.

Women's Mental Health Research: The Emergence of a Biomedical Field

This review surveys the field of women's mental health, with particular emphasis on its evolution into a distinct area of biomedical research. The field employs a biomedical disease model but it also emphasizes social and cultural influences on health outcomes. In recent years, its scope has expanded beyond studies of disorders occurring in women at times of reproductive transitions and it now encompasses a broader study of sex and gender differences. Historical and conceptual influences on the field are discussed. The review also surveys gender differences in the prevalence and clinical manifestations of mental disorders. Epidemiological findings have provided a rich resource for theory development, but without research tools to test theories adequately, findings of gender differences have begged the question of their biological, social, and cultural origins. Clinical depression is used to exemplify the usefulness of a sex/gender perspective in understanding mental illness; and major theories proposed to account for gender differences are critically evaluated. The National Institutes of Health (NIH) is the primary federal funding source for biomedical women's mental health research. The review surveys areas of emphasis in women's mental health research at the NIH as well as some collaborative activities that represent efforts to translate research findings into the public health and services arenas. As new analytic methods become available, it is anticipated that a more fundamental understanding of the biological and behavioral mechanisms underlying sex and gender differences in mental illness will emerge. Nonetheless, it is also likely that integration of findings predicated on different conceptual models of the nature and causes of mental illness will remain a challenge. These issues are discussed with reference to their impact on the field of women's mental health research.

Effect of gender on antinociceptive effect of paroxetine in hot plate test in mice

PURPOSE

Many studies have reported both a gender difference in the rates of depression and its treatment by using any of the widely used antidepressant drug groups. Some studies suggest that females respond more poorly to tricyclic antidepressants than males and appear to respond better to selective serotonin reuptake inhibitors (SSRI). There is no study investigating the analgesic/antinociceptive effects of antidepressant drugs on the basis of gender difference. In this study, we aimed to investigate the antinociceptive effect of paroxetine on the basis of gender difference.

METHODS

The antinociceptive effect of paroxetine was tested using hot plate test in Balb/c mice (30-40 g). The animals were divided into eight groups on the basis of gender.

FINDINGS

While paroxetine did not induce an antinociceptive effect in both sex at a dose of 1 mg kg(-1), it showed significant antinociceptive effects in both sex at a dose of 5 or 10 mg kg(-1). None of the doses of paroxetine revealed a gender difference in its antinociceptive action.

CONCLUSION

There are several studies showing positive or negative evidence on the gender difference of paroxetine's antidepressant effect, but in the literature there is no study about the gender difference of paroxetine's or any other SSRI drug's antinociceptive effect. In conclusion, our results do not show any gender difference in antinociceptive effect of paroxetine that may be important especially when it would be used as an adjuvant agent in some painful conditions.

Gender differences in efficacy and sexual function in long-term trazodone treatment (preliminary results)

Objects. To evaluate the effect of trazodone on depressive or anxiety symptoms and sexual function depending on patient gender. Method. A total of 111 patients (59 men, 52 women) subjected to long-term treatment with trazodone were studied. The effect of the therapy was recorded according to the Clinical Global Impression - Severity of Illness (CGI-S) scale. The incidence of sexual dysfunction was assessed on the Utvalg for Kliniske Undersogelser (UKU) scale. Results. The effect of the therapy was similar in both genders. The incidence of diminished sexual desire was low and comparable in both genders; orgasmic dysfunctions were present only in women at the level of statistical significance. A positive correlation between the severity of the illness and the occurrence of diminished sexual desire and orgasmic dysfunction was found in women but not in men. Conclusion. The occurrence of sexual dysfunctions in trazodone therapy was lower than in population. It seems that trazodone is an effective therapy of depressive and anxiety symptoms in both genders and it is convenient for sexually active patients, because the occurrence of sexual dysfunctions was present the general to a low degree.

The results of the Swiss observational study of the new, fast-dissolving mirtazapine formulation in depressed patients

Objective. The purpose of the present study was to document the experience with the use of a new, fast-dissolving oral tablet (FDT, RemeronSolTab®) of mirtazapine, a NaSSA antidepressant, in the treatment of depressed patients in daily practice in Switzerland. Methods. It was an open, prospective collection of observations in a total of 1121 depressive patients (>18 years old, both sexes). The treatment duration was 8 weeks with assessments after the second and eighth week. Efficacy measures were CGI (seven points) and specific check-lists for the ratings of severity of anxiety and sleep disturbances. At the end of the trial the acceptance (eight-item questionnaire) of the new formulation was recorded too. Results. The results showed that there was highly significant (P<0.001) and rapid improvement of severity of depression, anxiety and sleep disturbances in the whole population. Subgroup analyses showed that the antidepressant efficacy was independent of gender, initial severity of depression or of the type of depression (first episode, recurrent, chronic depression). The majority of patients (80%) liked at least one of the properties of FDT and, out of 75% of patients having experience with conventional tablet, 50% stated to be better compliant with this new formulation. Conclusion. This report documents the antidepressant efficacy of mirtazapine FDT. The new formulation found good acceptance by the patients. The results also suggest a likelihood of improved compliance with the mirtazapine FDT.

Relative Antidepressant Efficacy of Venlafaxine and SSRIs: Sex-Age Interactions

OBJECTIVE

To investigate whether differences in antidepressant efficacy are moderated by an interaction of age and gender.

METHODS

A pooled dataset from eight randomized, controlled trials of patients with major depressive disorder (MDD) was reanalyzed to compare remission rates following therapy with venlafaxine (n = 851), one of several selective serotonin reuptake inhibitors (SSRIs) (n = 748), or placebo (n = 446). Remission was defined as a final Hamilton Rating Scale for Depression (HAM-D) score < or =7. Pairwise comparisons were conducted using stepwise multiple logistic regression models with main effect and interaction terms for treatment, sex, and age (younger: <50; older: > or =50). Among older women, the impact of hormone replacement therapy (HRT) on remission rates also was examined.

RESULTS

Remission rates on venlafaxine therapy were not affected by age, sex, or HRT use. Among women, but not men, there was a significant interaction reflecting poorer SSRI response in the older age group (Wald chi-square = 4.21, df = 1, p = 0.04); HRT appeared to eliminate this difference. Whereas the advantage in remission rates favoring venlafaxine was modest for men and younger women (6%-9%), the difference among older women not taking HRT was 23%.

CONCLUSIONS

These findings provide further evidence that age, gender, and HRT moderate response to antidepressant medications.

Sex differences in antidepressant response in recent antidepressant clinical trials

Some previous reports suggest that women respond differently than men to antidepressant treatment. Much of this literature compares men and women's response to tricyclics to that of newer antidepressants (SSRIs, SNRI), or only examines one particular antidepressant. This study compares men and women's responses to 6 newer antidepressants. A total of 15 randomized, placebo-controlled trials that included 323 depressed patients were examined for sex differences in antidepressant treatment response. Women had a significantly greater response than men to SSRI antidepressants. A similar trend was seen for those assigned to an SNRI antidepressant, although not to the same extent as with SSRI antidepressants. Although these gender differences in treatment response are not large enough to suggest that gender should guide the clinical use of SSRI and SNRI antidepressants, the results do have implications for the design and interpretation of antidepressant clinical trials. These findings also raise the possibility that antidepressants may work somewhat differently in men and women.

Post-traumatic stress disorder in women: epidemiological and treatment issues

Although women are exposed to proportionately fewer traumatic events in their lifetime than men, they have a higher lifetime risk of post-traumatic stress disorder (PTSD). In addition to gender-differential rates of rape and sexual assault, including greater exposure to intimate partner violence, the preponderance of PTSD in women may be attributable to factors other than trauma type, such as sensitisation of stress hormone systems in response to early adverse experiences, inherent neuroendocrine factors, subjective interpretation of the event, and peritraumatic dissociation. Women with PTSD arguably experience a greater symptom burden, longer course of illness and have worse quality-of-life outcomes than men. An expanding knowledge base of the psychobiological alterations in PTSD is providing stimulus for the development of improved pharmacological and psychosocial treatment options. Recent randomised controlled studies conducted in large samples of women with chronic PTSD indicate that: (i) SSRIs have efficacy on all three symptom clusters of PTSD and should be used as first-line pharmacotherapy; and (ii) cognitive behavioural strategies (e.g. prolonged exposure treatment and cognitive processing) are effective in sexually and non-sexually assaulted women. Studies also suggest that female gender may be associated with better response rates to pharmacotherapy. Emerging empirical data on the potential usefulness of antiadrenergic agents and preventive cognitive behavioural treatments in managing acute trauma reactions and stemming the emergence of PTSD are paving the way for further work in this area. However, additional innovative treatments are needed for traumatised women and for female children/adolescents presenting with acute stress reactions and PTSD.