Early postnatal treatment with clomipramine induces female sexual behavior and estrous cycle impairment

Practical solutions for including sex as a biological variable (SABV) in preclinical neuropsychopharmacological research

Recently, many funding agencies have released guidelines on the importance of considering sex as a biological variable (SABV) as an experimental factor, aiming to address sex differences and avoid possible sex biases to enhance the reproducibility and translational relevance of preclinical research. In neuroscience and pharmacology, the female sex is often omitted from experimental designs, with researchers generalizing male-driven outcomes to both sexes, risking a biased or limited understanding of disease mechanisms and thus potentially ineffective therapeutics. Herein, we describe key methodological aspects that should be considered when sex is factored into in vitro and in vivo experiments and provide practical knowledge for researchers to incorporate SABV into preclinical research. Both age and sex significantly influence biological and behavioral processes due to critical changes at different timepoints of development for males and females and due to hormonal fluctuations across the rodent lifespan. We show that including both sexes does not require larger sample sizes, and even if sex is included as an independent variable in the study design, a moderate increase in sample size is sufficient. Moreover, the importance of tracking hormone levels in both sexes and the differentiation between sex differences and sex-related strategy in behaviors are explained. Finally, the lack of robust data on how biological sex influences the pharmacokinetic (PK), pharmacodynamic (PD), or toxicological effects of various preclinically administered drugs to animals due to the exclusion of female animals is discussed, and methodological strategies to enhance the rigor and translational relevance of preclinical research are proposed.

Mechanisms underlying remediation of depression-associated anxiety by chronic N-acetyl cysteine treatment

RATIONALE

Anxiety is one of the most comorbid conditions with major depressive disorder (MDD). Depression-associated anxiety often stems from the dysfunctional hypothalamic-pituitary-adrenal (HPA) axis and its altered regulation by the amygdala. Furthermore, MDD is associated with altered glutamatergic processing leading to anxiety and impaired regulation of the HPA axis. Recent studies have demonstrated that N-acetyl cysteine (NAC), a pleiotropic drug, exerts antidepressant-like effect by modulation of hippocampal functions, periterminal release of glutamate, and/or redox systems. However, the effects of NAC on depression-associated anxiety, HPA axis hyperactivity, and amygdalar dysfunctions are relatively unknown.

OBJECTIVES

Accordingly, we evaluated the effect of NAC on neonatal clomipramine (CLI)-induced adulthood anxiety and accompanying changes in plasma corticosterone levels, amygdalar volumes, neuronal/glial densities, levels of monoamines, and their metabolites in the amygdalar complex.

RESULTS

We found that chronic treatment with NAC reverses CLI-induced anhedonia and enhanced anxiety. Interestingly, attenuation of CLI-associated anxiety in NAC-treated rats were accompanied by a reversal of adrenal and spleen hypertrophy, and normalization of enhanced plasma corticosterone levels, indicating improved HPA axis functioning. Furthermore, NAC treatment was sufficient to reverse volumetric hypertrophy of basolateral amygdala (BLA), and altered noradrenaline (NA) metabolism in the amygdalar complex. The effects of NAC in the reversal of CLI-induced impairments were similar to that of fluoxetine (FLX).

CONCLUSIONS

We suggest that beneficial effects of NAC on antidepressive- and antianxiety-like behaviors are at least in part mediated via restoration of amygdalar and HPA axis functioning. Our results support the hypothesis that NAC might be evolved as a therapeutic strategy for reversal of amygdalar dysfunction in depression.

Antidepressant Use During Development May Impair Women's Sexual Desire in Adulthood

INTRODUCTION

Although antidepressants are well known to cause sexual side effects in adults, the long-term effects of antidepressant use during development on adult sexual function is unknown.

AIM

To explore differences in sexual desire and sexual behavior between adults who did vs did not use antidepressants during childhood or adolescence.

METHODS

An online survey of 610 young adults (66% women) assessed childhood and current mental health and use of antidepressants and other psychiatric medications before the age of 16 years and currently, partnered and solitary sexual desire, and frequency of masturbation and partnered sexual activity. Antidepressants were coded into either selective serotonin reuptake inhibitors (SSRIs) or non-SSRI antidepressants.

MAIN OUTCOME MEASURE

Scores on the Sexual Desire Inventory, and self-reported frequency of masturbation and partnered sexual activity.

RESULTS

For women, childhood SSRI use was associated with significantly lower solitary sexual desire, desire for an attractive other, and frequency of masturbation. This was true even when controlling for childhood mental health concerns, current mental health, and current antidepressant use. However, there was no effect of childhood SSRI use on women's partnered sexual desire or partnered sexual activity. There was no significant effect of childhood antidepressant use on men's sexual desire or masturbation. However, in men, childhood use of non-SSRI antidepressants was associated with significantly higher frequency of partnered sexual activity. Childhood use of non-SSRI antidepressants, or nonantidepressant psychiatric medication, was not associated with adult sexual desire or behavior in either women or men.

CLINICAL IMPLICATIONS

It is possible that SSRI use during childhood interrupts the normal development of sexual reward systems, which may be a risk factor for sexual desire dysfunction in adult women.

STRENGTHS & LIMITATIONS

Strengths include a large sample, use of attention checks and validated measures, and careful assessment of childhood mental health history; however, generalizability is limited by a predominantly white, young adult sample. These data are cross-sectional, and therefore, causal explanations for the association between childhood SSRI use and adult sexual well-being should be considered preliminary, warranting replication.

CONCLUSION

These findings point to a critical need for well-controlled, prospective research on possible long-term effects of antidepressant use, particularly SSRI use, on the development of adult sexual well-being. Lorenz TK. Antidepressant Use During Development May Impair Women's Sexual Desire in Adulthood. J Sex Med 2020;17:470-476.