Neural correlates of antidepressant-related sexual dysfunction: a placebo-controlled fMRI study on healthy males under subchronic paroxetine and bupropion

Effects of the glucagon-like peptide-1 receptor agonist dulaglutide on sexuality in healthy men: a randomised, double-blind, placebo-controlled crossover study

BACKGROUND

The reward-regulatory properties of GLP-1 are attracting increasing interest. Animal studies show that GLP-1 receptor agonists not only reduce consumption of addictive substances, but also influence sexual behaviour. We aimed to investigate the effect of dulaglutide versus placebo on sexual desire in humans.

METHODS

In this randomised, double-blind, placebo-controlled crossover trial, healthy eugonadal men of normal weight, aged 18-50 years with active and satisfactory sex lifes were (1:1) randomly allocated to dulaglutide or placebo for four weeks. We assessed sexual desire (Massachusetts General Hospital-Sexual Functioning Questionnaire [MGH-SFQ]), hormones of the hypothalamic-pituitary-gonadal axis (total testosterone, follicle-stimulating hormone [FSH], luteinizing hormone [LH]) and sperm parameters. Changes in these parameters were compared under dulaglutide versus placebo using paired t-tests.

FINDINGS

24 out of 26 randomised participants completed the study (13 participants randomised to dulaglutide first and 13 to placebo first). No change in the MGH-SFQ was observed after four weeks of dulaglutide versus placebo (estimated difference 0.58 [95% CI -0.83 to 2.00], p-value = 0.402). Hormones of the hypothalamic-pituitary-gonadal axis (estimated differences: total testosterone (nmol/l) 0.9 [95% CI -1.5 to 3.3], FSH (IU/l) -0.2 [95% CI -0.3 to 0.0] and LH (IU/l) -0.8 [95% CI -1.5 to 0.0]) as well as sperm parameters all remained in the normal range without significant differences between the treatments. No severe adverse events occurred.

INTERPRETATION

In this study of healthy men, we found no evidence of negative impacts of a four-week treatment with the widely used GLP-1 receptor agonist dulaglutide on sexual desire, hypothalamic-pituitary-gonadal axis hormones or sperm parameters.

FUNDING

Swiss National Science Foundation (PZ00P3_193206), Gottfried and Julia Bangerter-Rhyner Foundation, Goldschmidt-Jacobson Foundation, Swiss Academy of Medical Sciences.

The Complex Role Played by the Default Mode Network during Sexual Stimulation: A Cluster-Based fMRI Meta-Analysis

The default mode network (DMN) is a complex network that plays a significant and active role during naturalistic stimulation. Previous studies that have used naturalistic stimuli, such as real-life stories or silent or sonorous films, have found that the information processing involved a complex hierarchical set of brain regions, including the DMN nodes. The DMN is not involved in low-level features and is only associated with high-level content-related incoming information. The human sexual experience involves a complex set of processes related to both external context and inner processes. Since the DMN plays an active role in the integration of naturalistic stimuli and aesthetic perception with beliefs, thoughts, and episodic autobiographical memories, we aimed at quantifying the involvement of the nodes of the DMN during visual sexual stimulation. After a systematic search in the principal electronic databases, we selected 83 fMRI studies, and an ALE meta-analysis was calculated. We performed conjunction analyses to assess differences in the DMN related to stimulus modalities, sex differences, and sexual orientation. The results show that sexual stimulation alters the topography of the DMN and highlights the DMN's active role in the integration of sexual stimuli with sexual schemas and beliefs.

Current Understanding of Compulsive Sexual Behavior Disorder and Co-occurring Conditions: What Clinicians Should Know about Pharmacological Options

Compulsive sexual behavior disorder (CSBD) has recently been recognized as a psychiatric disorder. Pharmacological treatments for CSBD have received little study and thus have limited empirical support. The main objective of the present work is to review existing literature on the efficacy of different drugs on the symptomatology of CSBD, including the subtype of problematic pornography use (PPU). The main pharmacological approaches to treating CSBD have included opioid antagonists (naltrexone and nalmefene), selective serotonin reuptake inhibitors (paroxetine, citalopram, fluoxetine, and sertraline), mood stabilizers (topiramate), tricyclic antidepressants (clomipramine), serotonin antagonist and reuptake inhibitors (nefazodone), and N-acetylcysteine. Since people with CSBD may experience different co-occurring disorders, these should be considered when choosing the best pharmacological treatment. Pharmacological therapy for CSBD/PPU has been suggested as an adjunct to psychological therapies, which, for the moment, have the most empirical evidence. However, to evaluate the efficacy of most of the drugs presented in this narrative review, data to date have only been available from case studies. Thus, empirical support is scant and generalizability of results is limited, highlighting the need for more research in this area.

Psychedelics and sexual functioning: a mixed-methods study

Do psychedelics affect sexual functioning postacutely? Anecdotal and qualitative evidence suggests they do, but this has never been formally tested. While sexual functioning and satisfaction are generally regarded as an important aspect of human wellbeing, sexual dysfunction is a common symptom of mental health disorders. It is also a common side effect of selective serotonin reuptake inhibitors (SSRIs), a first line treatment for depression. The aim of the present paper was to investigate the post-acute effects of psychedelics on self-reported sexual functioning, combining data from two independent studies, one large and naturalistic and the other a smaller but controlled clinical trial. Naturalistic use of psychedelics was associated with improvements in several facets of sexual functioning and satisfaction, including improved pleasure and communication during sex, satisfaction with one's partner and physical appearance. Convergent results were found in a controlled trial of psilocybin therapy versus an SSRI, escitalopram, for depression. In this trial, patients treated with psilocybin reported positive changes in sexual functioning after treatment, while patients treated with escitalopram did not. Despite focusing on different populations and settings, this is the first research study to quantitively investigate the effects of psychedelics on sexual functioning. Results imply a potential positive effect on post-acute sexual functioning and highlight the need for more research on this.

Switching to Vortioxetine in Patients with Poorly Tolerated Antidepressant-Related Sexual Dysfunction in Clinical Practice: A 3-Month Prospective Real-Life Study

Treatment-emergent sexual dysfunction (TESD) is one of the most frequent and persistent adverse effects of antidepressant medication. Sexual dysfunction (SD) secondary to SSRIs occurs in >60% of sexually active patients and >80% of healthy volunteers, with this causing treatment discontinuation in >35% of patients. However, this factor is rarely addressed in routine examinations, and only 15-30% of these events are spontaneously reported. A strategy of switching to a different non-serotonergic antidepressant could involve a risk of relapse or clinical worsening due to a lack of serotonergic activity. Vortioxetine appears to have less impact on sexual function due to its multimodal mechanism of action. No studies have been published on the effectiveness of switching to vortioxetine in patients with poorly tolerated long-term antidepressant-related SD in naturalistic settings.

STUDY OBJECTIVES

To determine the effectiveness of switching to vortioxetine due to SD in a routine clinical practice setting.

METHODOLOGY

observational pragmatic and naturalistic study to determine the effectiveness of the switch to vortioxetine (mean dosage 13.11 ± 4.03) in 74 patients aged 43.1 ± 12.65 (54% males) at risk of discontinuing treatment due to sexual dysfunction. The PRSexDQ*- SALSEX scale (* Psychotropic-Related Sexual Dysfunction Questionnaire) was applied at two moments: baseline visit and after 3 months of follow-up.

RESULTS

global Sexual Dysfunction (SD) measured with the SALSEX scale decreased significantly between the baseline visit (10.32; SD 2.73) and the follow-up visit (3.78; SD 3.68), p < 0.001. There was a significant improvement (p < 0.001) at the endpoint including decreased libido, delay of orgasm, anorgasmia and arousal difficulties in both sexes. After switching to vortioxetine, 83.81% of patients experienced an improvement in sexual function (43.2% felt greatly improved). Most patients (83.3%) who switched to vortioxetine continued treatment after the follow-up visit. A total of 58.1% of patients showed an improvement in depressive symptoms from the baseline visit.

CONCLUSION

switching to vortioxetine is an effective and reliable strategy to treat patients with poorly tolerated previous antidepressant-related sexual dysfunction in real-life clinical settings.

Post-Finasteride Syndrome And Post-Ssri Sexual Dysfunction: Two Clinical Conditions Apparently Distant, But Very Close

Post-finasteride syndrome and post-SSRI sexual dysfunction, are two poorly explored clinical conditions in which men treated for androgenetic alopecia with finasteride or for depression with SSRI antidepressants show persistent side effects despite drug suspension (e.g., sexual dysfunction, psychological complaints, sleep disorders). Because of some similarities in the symptoms, common pathological mechanisms are proposed here. Indeed, as discussed, clinical studies and preclinical data obtained so far suggest an important role for brain modulators (i.e., neuroactive steroids), neurotransmitters (i.e., serotonin, and cathecolamines), and gut microbiota in the context of the gut-brain axis. In particular, the observed interconnections of these signals in these two clinical conditions may suggest similar etiopathogenetic mechanisms, such as the involvement of the enzyme converting norepinephrine into epinephrine (i.e., phenylethanolamine N-methyltransferase). However, despite the current efforts, more work is still needed to advance the understanding of these clinical conditions in terms of diagnostic markers and therapeutic strategies.

Effects of bupropion and SSRI antidepressants on leg movement activity and chin muscle tone during sleep in adolescents

STUDY OBJECTIVES

To evaluate the effects of bupropion on periodic limb movements during sleep (PLMS) and chin electromyography tone in children taking it for their mood disorder, compared to the effects of selective serotonin reuptake inhibitors (SSRIs) and of bupropion combined with SSRIs.

METHODS

Six adolescents (aged 16.0 ± 0.63 years) taking bupropion alone and 6 adolescents (aged 15.9 ± 1.36 years) taking bupropion in combination with an SSRI antidepressant were recruited, along with 10 adolescents (aged 16.2 ± 0.2 years) taking different SSRIs, and they were also enrolled together with 17 age- and sex-matched control patients (aged 15.5 ± 1.26 years). Polysomnographic studies were obtained, and participants' leg movement activity during sleep and muscle tone were assessed quantitatively (atonia index) during all sleep stages.

RESULTS

Participants taking SSRIs showed PLMS indices significantly higher than those of control patients, whereas adolescents taking bupropion showed only slightly increased indexes of nonperiodic leg movements during sleep. No differences in PLMS were observed between adolescents taking bupropion alone or in association with SSRIs. The atonia index showed, within each sleep stage, the lowest values in the 2 groups taking SSRIs and the highest in the control patients; adolescents taking bupropion alone tended to show values slightly smaller than those of the control patients.

CONCLUSIONS

We found that similar to adults, in adolescents SSRIs but not bupropion are associated with increased PLMS. Bupropion also seems to counteract the SSRI-induced increase of PLMS, when administered in combination; thus, the dopaminergic effect of bupropion seems to outmatch the antidopaminergic action of SSRIs. Conversely, bupropion does not counteract the effects of SSRIs on chin electromyography tone.

CITATION

DelRosso LM, Mogavero MP, Fickensher A, Bruni O, Schenck CH, Ferri R. Effects of bupropion and SSRI antidepressants on leg movement activity and chin muscle tone during sleep in adolescents. J Clin Sleep Med. 2023;19(1):151-161.

The World Federation of Societies of Biological Psychiatry guidelines on the assessment and pharmacological treatment of compulsive sexual behaviour disorder

OBJECTIVES

The current guidelines aim to evaluate the role of pharmacological agents in the treatment of patients with compulsive sexual behaviour disorder (CSBD). They are intended for use in clinical practice by clinicians who treat patients with CSBD.

METHODS

An extensive literature search was conducted using the English-language-literature indexed on PubMed and Google Scholar without time limit, supplemented by other sources, including published reviews.

RESULTS

Each treatment recommendation was evaluated with respect to the strength of evidence for its efficacy, safety, tolerability, and feasibility. Psychoeducation and psychotherapy are first-choice treatments and should always be conducted. The type of medication recommended depended mainly on the intensity of CSBD and comorbid sexual and psychiatric disorders. There are few randomised controlled trials. Although no medications carry formal indications for CSBD, selective-serotonin-reuptake-inhibitors and naltrexone currently constitute the most relevant pharmacological treatments for the treatment of CSBD. In cases of CSBD with comorbid paraphilic disorders, hormonal agents may be indicated, and one should refer to previously published guidelines on the treatment of adults with paraphilic disorders. Specific recommendations are also proposed in case of chemsex behaviour associated with CSBD.

CONCLUSIONS

An algorithm is proposed with different levels of treatment for different categories of patients with CSBD.

Pharmaceutical management of sexual dysfunction in men on antidepressant therapy

INTRODUCTION

Sexual dysfunction (SD) and depression have a bidirectional relationship. The rising prescription of antidepressants, especially those with a serotonergic effect, is associated with increased SD. Sexual dysfunction reduces compliance and increases risk of recurrence of depressive episodes. Various strategies have been studied to manage antidepressant-induced SD.

AREAS COVERED

This review covers the identification of symptoms of antidepressant-induced SD, prevalence of symptoms in association with commonly used antidepressants, and the main lines of management, with a focus on pharmacological strategies.

EXPERT OPINION

The management of antidepressant-induced SD aims to reduce the unwanted sexual adverse effects while maintaining an acceptable control of depressive symptoms. It should implicate a multidisciplinary approach and determination of baseline sexual function and SD risk factors. In spite of several methodological issues, antidepressants can be divided into low- and high-risk categories with regard to the possibility of developing SD. In patients interested in sexual activity, it is recommended to start with low-risk antidepressants. Otherwise, encourage the patient to wait for tolerance and then switch to low-risk. In selected cases, dose reduction or a drug holiday may be applied. The adjunctive use of a PDE5i can help in a significant number of patients. Randomized controlled trials are needed to set high-level evidence-based recommendations.

Low concentrations of the antidepressant venlafaxine affect courtship behaviour and alter serotonin and dopamine systems in zebrafish (Danio rerio)

Venlafaxine, a serotonin-noradrenaline reuptake inhibitor, is a widely used antidepressant drug routinely detected in aquatic environments. However, its potential impact on courtship behaviour in zebrafish is unknown. We tested the hypothesis that venlafaxine disrupts brain monoamine levels and molecular responses essential for courtship behaviour in zebrafish. Zebrafish (Danio rerio) were exposed to venlafaxine (1, 10, and 100 μg/L) for 20 days. We evaluated the molecular levels and neuronal basis of the effect of venlafaxine on courtship behaviour. Here, we show that venlafaxine inhibited courtship behaviour in zebrafish and increased the transcript levels of 5-ht1a and 5-ht2c while decreasing the transcript levels of genes involved in the dopaminergic system, including th1, th2, drd1b, and drd2b. Venlafaxine upregulated 5-HT levels and downregulated dopamine levels. Moreover, the subordinate fish from the venlafaxine-exposed group had significantly lower motor activity than the subordinate fish of the control group. Collectively, our results reveal that venlafaxine can disturb brain monoamine levels, affecting courtship behaviour in adult zebrafish.

Effects of paroxetine treatment and its withdrawal on neurosteroidogenesis

Selective serotonin reuptake inhibitors (SSRI) show high efficacy in treating depression, however during treatment side effects, like for instance sexual dysfunction, may appear, decreasing compliance. In some cases, this condition will last after drug discontinuation, leading to the so-called post-SSRI sexual dysfunction (PSSD). The etiology of PSSD is still unknown, however a role for neuroactive steroids may be hypothesized. Indeed, these molecules are key physiological regulators of the nervous system, and their alteration has been associated with several neuropathological conditions, including depression. Additionally, neuroactive steroids are also involved in the control of sexual function. Interestingly, sexual dysfunction induced by SSRI treatment has been also observed in animal models. On this basis, we have here evaluated whether a subchronic treatment with paroxetine for two weeks and/or its withdrawal (i.e., a month) may affect the levels of neuroactive steroids in brain areas (i.e., hippocampus, hypothalamus, and cerebral cortex) and/or in plasma and cerebrospinal fluid of male rats. Data obtained indicate that the SSRI treatment alters neuroactive steroid levels and the expression of key enzymes of the steroidogenesis in a brain tissue- and time-dependent manner. Indeed, these observations with the finding that plasma levels of neuroactive steroids are not affected suggest that the effect of paroxetine treatment is directly on neurosteroidogenesis. In particular, a negative impact on the expression of steroidogenic enzymes was observed at the withdrawal. Therefore, it is possible to hypothesize that altered neurosteroidogenesis may also occur in PSSD and consequently it may represent a possible pharmacological target for this disorder.

Serotonergic regulation of the dopaminergic system: Implications for reward-related functions

Serotonin is a critical neuromodulator involved in development and behavior. Its role in reward is however still debated. Here, we first review classical studies involving electrical stimulation protocols and pharmacological approaches. Contradictory results on the serotonergic' involvement in reward emerge from these studies. These differences might be ascribable to either the diversity of cellular types within the raphe nuclei or/and the specific projection pathways of serotonergic neurons. We continue to review more recent work, using optogenetic approaches to activate serotonergic cells in the Raphe to VTA pathway. From these studies, it appears that activation of this pathway can lead to reinforcement learning mediated through the excitation of dopaminergic neurons by serotonergic neurons co-transmitting glutamate. Finally, given the importance of serotonin during development on adult emotion, the effect of abnormal early-life levels of serotonin on the dopaminergic system will also be discussed. Understanding the interaction between the serotonergic and dopaminergic systems during development and adulthood is critical to gain insight into the specific facets of neuropsychiatric disorders.

Great Expectations: A Critical Review of and Suggestions for the Study of Reward Processing as a Cause and Predictor of Depression

Both human and animal studies support the relationship between depression and reward processing abnormalities, giving rise to the expectation that neural signals of these processes may serve as biomarkers or mechanistic treatment targets. Given the great promise of this research line, we scrutinized those findings and the theoretical claims that underlie them. To achieve this, we applied the framework provided by classical work on causality as well as contemporary approaches to prediction. We identified a number of conceptual, practical, and analytical challenges to this line of research and used a preregistered meta-analysis to quantify the longitudinal associations between reward processing abnormalities and depression. We also investigated the impact of measurement error on reported data. We found that reward processing abnormalities do not reach levels that would be useful for clinical prediction, yet the available evidence does not preclude a possible causal role in depression.

Using pharmacological manipulations to study the role of dopamine in human reward functioning: A review of studies in healthy adults

Dopamine (DA) plays a key role in reward processing and is implicated in psychological disorders such as depression, substance use, and schizophrenia. The role of DA in reward processing is an area of highly active research. One approach to this question is drug challenge studies with drugs known to alter DA function. These studies provide good experimental control and can be performed in parallel in laboratory animals and humans. This review aimed to summarize results of studies using pharmacological manipulations of DA in healthy adults. 'Reward' is a complex process, so we separated 'phases' of reward, including anticipation, evaluation of cost and benefits of upcoming reward, execution of actions to obtain reward, pleasure in response to receiving a reward, and reward learning. Results indicated that i) DAergic drugs have different effects on different phases of reward; ii) the relationship between DA and reward functioning appears unlikely to be linear; iii) our ability to detect the effects of DAergic drugs varies depending on whether subjective, behavioral, imaging measures are used.

The role of dopaminergic and serotonergic transmission in the processing of primary and monetary reward

Natural rewards such as erotic stimuli activate common neural pathways with monetary rewards. In human studies, the manipulation of dopamine and serotonin play an important role in the processing of monetary rewards with less understood on its role on erotic stimuli. In this study, we investigate the neuromodulatory effects of dopaminergic and serotonergic transmission in the processing of erotic versus monetary visual stimuli. We scanned one hundred and two (N = 102) healthy volunteers using functional magnetic resonance imaging while performing a modified version of the well-validated monetary incentive delay task consisting of erotic, monetary and neutral visual stimuli. We show a role for enhanced central dopamine and lowered central serotonin levels in increasing activity in the right caudate and left anterior insula during anticipation of erotic relative to monetary rewards in healthy controls. We further show differential activation in the anticipation of natural versus monetary rewards with the former associated with ventromesial and dorsomesial activity and the latter with dorsal cingulate, striatal and anterior insular activity. These findings are consistent with preclinical and clinical findings of a role for dopaminergic and serotonergic mechanisms in the processing of natural rewards. Our study provides further insights into the neural substrates underlying reward processing for natural primary erotic rewards and yields importance for the neurochemical systems of addictive disorders including gambling disorder.

Panic Disorder Correlates With the Risk for Sexual Dysfunction

BACKGROUND

Reports have suggested that sexual dysfunction is an underestimated complication of panic disorder, but little research has focused on sexual dysfunction associated specifically with panic disorder. The purpose of this systematic review was to investigate whether patients with panic disorder who are not currently receiving treatment had a higher risk of sexual dysfunction than healthy people, as well as to clarify the appropriate treatment for this patient group.

METHODS

Articles that reported panic disorder complicated with sexual dysfunction were identified by a systematic literature search of electronic databases, including PubMed, the Cochrane databases, EMBASE, and PsycINFO.

RESULTS

Six articles were included in the review. Patients with panic disorder showed a high prevalence of sexual aversion (35.7% to 64%) and sexual infrequency (36% to 44%). One cohort study indicated that untreated patients with panic disorders had a higher risk of erectile dysfunction than controls. Another article that focused specifically on female patients reported that the patients with panic disorder exhibited decreased frequency of sexual behavior and decreased sexual desire compared with the controls. However, 2 studies found conflicting results after adjustment for confounding factors.

CONCLUSIONS

Although the results were mixed, it appears that patients with panic disorder tended to be more susceptible to sexual dysfunction than the general population. Further trials with larger sample sizes and rigorous research designs are needed to establish the relationship between sexual dysfunction and panic disorder.

Context effects on probability estimation

Many decisions rely on how we evaluate potential outcomes and estimate their corresponding probabilities of occurrence. Outcome evaluation is subjective because it requires consulting internal preferences and is sensitive to context. In contrast, probability estimation requires extracting statistics from the environment and therefore imposes unique challenges to the decision maker. Here, we show that probability estimation, like outcome evaluation, is subject to context effects that bias probability estimates away from other events present in the same context. However, unlike valuation, these context effects appeared to be scaled by estimated uncertainty, which is largest at intermediate probabilities. Blood-oxygen-level-dependent (BOLD) imaging showed that patterns of multivoxel activity in the dorsal anterior cingulate cortex (dACC), ventromedial prefrontal cortex (VMPFC), and intraparietal sulcus (IPS) predicted individual differences in context effects on probability estimates. These results establish VMPFC as the neurocomputational substrate shared between valuation and probability estimation and highlight the additional involvement of dACC and IPS that can be uniquely attributed to probability estimation. Because probability estimation is a required component of computational accounts from sensory inference to higher cognition, the context effects found here may affect a wide array of cognitive computations.

This study shows how probability estimation can be affected by the context of our recent experience, namely, how the presence of multiple events experienced closed in time can influence their respective probability estimates.

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.

Data-Driven Approaches to Neuroimaging Analysis to Enhance Psychiatric Diagnosis and Therapy

Combining advanced neuroimaging with novel computational methods in network science and machine learning has led to increasingly meaningful descriptions of structure and function in both the normal and the abnormal brain, thereby contributing significantly to our understanding of psychiatric disorders as circuit dysfunctions. Despite its marked potential for psychiatric care, this approach has not yet extended beyond the research setting to any clinically useful applications. Here we review current developments in the study of neuroimaging data using network models and machine learning methods, with a focus on their promise in offering a framework for clinical translation. We discuss 3 potential contributions of these methods to psychiatric care: 1) a better understanding of psychopathology beyond current diagnostic boundaries; 2) individualized prediction of treatment response and prognosis; and 3) formal theories to guide the development of novel interventions. Finally, we highlight current obstacles and sketch a forward-looking perspective of how the application of machine learning and network modeling methods should proceed to accelerate their potential transformation of clinically useful tools.

Management Strategies for Antidepressant-Related Sexual Dysfunction: A Clinical Approach

Major depressive disorder is a serious mental disorder in which treatment with antidepressant medication is often associated with sexual dysfunction (SD). Given its intimate nature, treatment emergent sexual dysfunction (TESD) has a low rate of spontaneous reports by patients, and this side effect therefore remains underestimated in clinical practice and in technical data sheets for antidepressants. Moreover, the issue of TESD is rarely routinely approached by clinicians in daily praxis. TESD is a determinant for tolerability, since this dysfunction often leads to a state of patient distress (or the distress of their partner) in the sexually active population, which is one of the most frequent reasons for lack of adherence and treatment drop-outs in antidepressant use. There is a delicate balance between prescribing an effective drug that improves depressive symptomatology and also has a minimum impact on sexuality. In this paper, we detail some management strategies for TESD from a clinical perspective, ranging from prevention (carefully choosing an antidepressant with a low rate of TESD) to possible pharmacological interventions aimed at improving patients’ tolerability when TESD is present. The suggested recommendations include the following: for low sexual desire, switching to a non-serotoninergic drug, lowering the dose, or associating bupropion or aripiprazole; for unwanted orgasm delayal or anorgasmia, dose reduction, “weekend holiday”, or switching to a non-serotoninergic drug or fluvoxamine; for erectile dysfunction, switching to a non-serotoninergic drug or the addition of an antidote such as phosphodiesterase 5 inhibitors (PD5-I); and for lubrication difficulties, switching to a non-serotoninergic drug, dose reduction, or using vaginal lubricants. A psychoeducational and psychotherapeutic approach should always be considered in cases with poorly tolerated sexual dysfunction.

Frequency of Sexual Dysfunction in Patients Treated with Desvenlafaxine: A Prospective Naturalistic Study

Despite being clinically underestimated, sexual dysfunction (SD) is one of the most frequent and lasting adverse effects associated with antidepressants. Desvenlafaxine is an antidepressant (AD) with noradrenergic and serotonergic action that can cause a lower SD than other serotonergic ADs although there are still few studies on this subject. Objective: To check the frequency of SD in two groups of depressive patients: one group was desvenlafaxine-naïve; the other was made up of patients switched to desvenlafaxine from another AD due to iatrogenic sexual dysfunction. A naturalistic, multicenter, and prospective study of patients receiving desvenlafaxine (50–100 mg/day) was carried out on 72 patients who met the inclusion criteria (>18 years old and sexually active), who had received desvenlafaxine for the first time (n = 27) or had switched to desvenlafaxine due to SD with another AD (n = 45). Patients with previous SD, receiving either drugs or presenting a concomitant pathology that interfered with their sexual life and/or patients who abused alcohol and/or drugs were excluded. We used the validated Psychotropic-Related Sexual Dysfunction Questionnaire (PRSexDQ-SALSEX) to measure AD-related sexual dysfunction and the Clinical Global Impression Scale for psychiatric disease (CGI-S) and for sexual dysfunction (CGI-SD) at two points in time: baseline and three months after the commencement of desvenlafaxine treatment. Results: In desvenlafaxine-naïve patients, 59.2% of the sample showed moderate/severe sexual dysfunction at baseline, which was reduced to 44% at follow-up. The PSexDQ-SALSEX questionnaire total score showed a significant improvement in sexual desire and sexual arousal without changes in orgasmic function at follow-up (p < 0.01). In the group switched to desvenlafaxine, the frequency of moderate/severe SD at baseline (93.3%) was reduced to 75.6% at follow-up visit. Additionally, SD significantly improved in three out of four items of the SALSEX: low desire, delayed orgasm, and anorgasmia at follow-up (p < 0.01), but there was no significant improvement in arousal difficulties. The frequency of severe SD was reduced from 73% at baseline to 35% at follow-up. The CGI for psychiatric disease and for sexual dysfunction improved significantly in both groups (p < 0.01). There was a poor tolerability with risk of treatment noncompliance in 26.7% of patients with sexual dysfunction due to another AD, this significantly reduced to 11.1% in those who switched to desvenlafaxine (p = 0.004). Conclusion: Sexual dysfunction improved significantly in depressed patients who initiated treatment with desvenlafaxine and in those who switched from another AD to desvenlafaxine, despite this, desvenlafaxine treatment is not completely devoid of sexual adverse effects. This switching strategy could be highly relevant in clinical practice due to the significant improvement in moderate/severe and poorly tolerated SD, while maintaining the AD efficacy.

Serotonergic, Dopaminergic, and Noradrenergic Modulation of Erotic Stimulus Processing in the Male Human Brain

Human sexual behavior is mediated by a complex interplay of cerebral and spinal centers, as well as hormonal, peripheral, and autonomic functions. Neuroimaging studies identified central neural signatures of human sexual responses comprising neural emotional, motivational, autonomic, and cognitive components. However, empirical evidence regarding the neuromodulation of these neural signatures of human sexual responses was scarce for decades. Pharmacological functional magnetic resonance imaging (fMRI) provides a valuable tool to examine the interaction between neuromodulator systems and functional network anatomy relevant for human sexual behavior. In addition, this approach enables the examination of potential neural mechanisms regarding treatment-related sexual dysfunction under psychopharmacological agents. In this article, we introduce common neurobiological concepts regarding cerebral sexual responses based on neuroimaging findings and we discuss challenges and findings regarding investigating the neuromodulation of neural sexual stimulus processing. In particular, we summarize findings from our research program investigating how neural correlates of sexual stimulus processing are modulated by serotonergic, dopaminergic, and noradrenergic antidepressant medication in healthy males.

Understanding the Mechanism of Antidepressant-Related Sexual Dysfunction: Inhibition of Tyrosine Hydroxylase in Dopaminergic Neurons after Treatment with Paroxetine but Not with Agomelatine in Male Rats

Antidepressant-related sexual dysfunction is a frequent adverse event caused by serotonergic activation that intensely affects quality of life and adherence in depressed patients. The dopamine system has multiple effects promoting sexual behavior, but no studies have been carried out to confirm dopaminergic changes involved in animal models after antidepressant use. Methods: The sexual behavior-related dopaminergic system in the rat was studied by comparing two different antidepressants and placebo for 28 days. The antidepressants used were paroxetine (a serotonergic antidepressant that causes highly frequent sexual dysfunction in humans) and agomelatine (a non-serotonergic antidepressant without associated sexual dysfunction). The tyrosine hydroxylase immunoreactivity (THI) in the substantia nigra pars compacta, the ventral tegmental area, the zona incerta, and the hypothalamic arcuate nucleus, as well as the dopaminergic projections to the striatum, hippocampus, cortex, and median eminence were analyzed. Results: The THI decreased significantly in the substantia nigra and ventral tegmental area after treatment with paroxetine, and the labeling was reduced drastically in the zona incerta and mediobasal hypothalamus. The immunoreactive axons in the target regions (striatum, cortex, hippocampus, and median eminence) almost disappeared only in the paroxetine-treated rats. Conversely, after treatment with agomelatine, a moderate reduction in immunoreactivity in the substantia nigra was found without appreciable modifications in the ventral tegmental area, zona incerta, and mediobasal hypothalamus. Nevertheless, no sexual or copulatory behavior was observed in any of the experimental or control groups. Conclusion: Paroxetine but not agomelatine was associated with important decreased activity in dopaminergic areas such as the substantia nigra and ventral tegmental areas that could be associated with sexual performance impairment in humans after antidepressant treatment.

Post-finasteride syndrome and post-SSRI sexual dysfunction: two sides of the same coin?

Sexual dysfunction is a clinical condition due to different causes including the iatrogenic origin. For instance, it is well known that sexual dysfunction may occur in patients treated with antidepressants like selective serotonin reuptake inhibitors (SSRI). A similar side effect has been also reported during treatment with finasteride, an inhibitor of the enzyme 5alpha-reductase, for androgenetic alopecia. Interestingly, sexual dysfunction persists in both cases after drug discontinuation. These conditions have been named post-SSRI sexual dysfunction (PSSD) and post-finasteride syndrome (PFS). In particular, feeling of a lack of connection between the brain and penis, loss of libido and sex drive, difficulty in achieving an erection and genital paresthesia have been reported by patients of both conditions. It is interesting to note that the incidence of these diseases is probably so far underestimated and their etiopathogenesis is not sufficiently explored. To this aim, the present review will report the state of art of these two different pathologies and discuss, on the basis of the role exerted by three different neuromodulators such as dopamine, serotonin and neuroactive steroids, whether the persistent sexual dysfunction observed could be determined by common mechanisms.

Differential Noradrenergic Modulation of Monetary Reward and Visual Erotic Stimulus Processing

We recently investigated the effects of the noradrenergic antidepressant reboxetine and the antipsychotic amisulpride compared to placebo on neural correlates of primary reinforcers by visual erotic stimulation in healthy subjects. Whereas, amisulpride left subjective sexual functions and corresponding neural activations unimpaired, attenuated neural activations were observed under reboxetine within the nucleus accumbens (Nacc) along with diminished behavioral sexual functioning. However, a global dampening of the reward system under reboxetine seemed not intuitive considering the complementary role of the noradrenergic to the dopamine system in reward-related learning mediated by prediction error processing. We therefore investigated the sample of 17 healthy males in a mean age of 23.8 years again by functional magnetic resonance imaging (fMRI), to explore the noradrenergic effects on neural reward prediction error signaling. Participants took reboxetine (4 mg/d), amisulpride (200 mg/d), and placebo each for 7 days within a randomized, double-blind, within-subject cross-over design. During fMRI, we used an established monetary incentive task to assess neural reward expectation and prediction error signals within the bilateral Nacc using an independent anatomical mask for a region of interest (ROI) analysis. Activations within the same ROI were also assessed for the erotic picture paradigm. We confirmed our previous results from the whole brain analysis for the selected ROI by significant (p < 0.05 FWE-corrected) attenuated activations within the Nacc during visual sexual stimulation under reboxetine compared to placebo. However, activations in the Nacc concerning prediction error processing and monetary reward expectation were unimpaired under reboxetine compared to placebo, along with unimpaired reaction times in the reward task. For both tasks, neural activations and behavioral processing were not altered by amisulpride compared to placebo. The observed attenuated neural activations within the Nacc during visual erotic stimulation along with unimpaired neural prediction error and monetary reward expectation processing provide evidence for a differential modulation of the neural reward system by the noradrenergic agent reboxetine depending on the presence of primary reinforcers such as erotic stimuli in contrast to secondary such as monetary rewards.

Noradrenergic modulation of neural erotic stimulus perception

We recently investigated neuromodulatory effects of the noradrenergic agent reboxetine and the dopamine receptor affine amisulpride in healthy subjects on dynamic erotic stimulus processing. Whereas amisulpride left sexual functions and neural activations unimpaired, we observed detrimental activations under reboxetine within the caudate nucleus corresponding to motivational components of sexual behavior. However, broadly impaired subjective sexual functioning under reboxetine suggested effects on further neural components. We now investigated the same sample under these two agents with static erotic picture stimulation as alternative stimulus presentation mode to potentially observe further neural treatment effects of reboxetine. 19 healthy males were investigated under reboxetine, amisulpride and placebo for 7 days each within a double-blind cross-over design. During fMRI static erotic picture were presented with preceding anticipation periods. Subjective sexual functions were assessed by a self-reported questionnaire. Neural activations were attenuated within the caudate nucleus, putamen, ventral striatum, the pregenual and anterior midcingulate cortex and in the orbitofrontal cortex under reboxetine. Subjective diminished sexual arousal under reboxetine was correlated with attenuated neural reactivity within the posterior insula. Again, amisulpride left neural activations along with subjective sexual functioning unimpaired. Neither reboxetine nor amisulpride altered differential neural activations during anticipation of erotic stimuli. Our results verified detrimental effects of noradrenergic agents on neural motivational but also emotional and autonomic components of sexual behavior. Considering the overlap of neural network alterations with those evoked by serotonergic agents, our results suggest similar neuromodulatory effects of serotonergic and noradrenergic agents on common neural pathways relevant for sexual behavior.

Neural underpinnings of prosexual effects induced by gamma-hydroxybutyrate in healthy male humans

Gamma-hydroxybutyrate (GHB) is a GHB-/GABA_B-receptor agonist currently used as treatment for narcolepsy but also as a drug of abuse. Non-medical GHB users have repeatedly reported prosexual effects including libido-enhancement and lowering of attractiveness standards for partner selection. Here, we examined the putative prosexual effects of oral GHB in healthy males in two experiments both employing randomized, placebo-controlled, double-blind, balanced, and cross-over study designs. In experiment I, subjective effects of 20 and 35mg/kg GHB vs. placebo were tested in 32 participants using the Sexual Arousal and Desire Inventory. In experiment II, brain reactivity towards erotic vs. neutral pictures was investigated in 15 participants using functional magnetic resonance imaging after 35mg/kg GHB vs. placebo. In experiment I, prosexual effects of GHB were shown by increased SADI ratings regarding physiological, evaluative, and motivational aspects of sexual arousal. In experiment II, erotic visual stimuli activated the bilateral insula, nucleus accumbens (NAcc), fusiform gyrus, thalamus, and left occipital pole under placebo. After GHB administration, even sexually neutral pictures of persons induced subjective sexual arousal and increased activation of the bilateral NAcc and right anterior cingulate cortex, which significantly correlated (left NAcc by trend). Moreover, a psychophysiological interaction analysis showed that GHB increased connectivity between NAcc and ventromedial prefrontal cortex during processing of visual erotic cues, i.e., in the condition in which subjective sexual arousal was highest. Our data show that GHB stimulates hedonic sexual functioning and lowers the threshold for erotic perception, which is related to increased susceptibility of mesolimbic reward pathways.

Functional insights into aberrant brain responses and integration in patients with lifelong premature ejaculation

Even though lifelong premature ejaculation (PE) is highly prevalent, few studies have investigated the neural mechanisms underlying PE. The extent and pattern of brain activation can be determined through a version of functional magnetic resonance imaging (fMRI) with erotic picture stimuli (task fMRI) and a resting-state fMRI (rs fMRI). We showed that the brain activity in the left inferior frontal gyrus and left insula was decreased both during the task and in the resting state, while there was higher activation in the right middle temporal gyrus during the task. Higher functional connectivity was found in PE between those three brain areas and the bilateral middle cingulate cortex, right middle frontal gyrus and supplementary motor area. Moreover, the brain activity had positive correlation with clinical rating scales, such as intravaginal ejaculatory latency time (IELT) and the Chinese Index of Premature Ejaculation (CIPE). These findings revealed that brain responses and functional integration in certain brain areas are impaired in cases of PE, which was consistently supported by multiple measurements obtained using a task and rs fMRI approach.

Investigating the Predictive Value of Functional MRI to Appetitive and Aversive Stimuli: A Pattern Classification Approach

Background

Dysfunctional neural responses to appetitive and aversive stimuli have been investigated as possible biomarkers for psychiatric disorders. However it is not clear to what degree these are separate processes across the brain or in fact overlapping systems. To help clarify this issue we used Gaussian process classifier (GPC) analysis to examine appetitive and aversive processing in the brain.

Method

25 healthy controls underwent functional MRI whilst seeing pictures and receiving tastes of pleasant and unpleasant food. We applied GPCs to discriminate between the appetitive and aversive sights and tastes using functional activity patterns.

Results

The diagnostic accuracy of the GPC for the accuracy to discriminate appetitive taste from neutral condition was 86.5% (specificity = 81%, sensitivity = 92%, p = 0.001). If a participant experienced neutral taste stimuli the probability of correct classification was 92. The accuracy to discriminate aversive from neutral taste stimuli was 82.5% (specificity = 73%, sensitivity = 92%, p = 0.001) and appetitive from aversive taste stimuli was 73% (specificity = 77%, sensitivity = 69%, p = 0.001). In the sight modality, the accuracy to discriminate appetitive from neutral condition was 88.5% (specificity = 85%, sensitivity = 92%, p = 0.001), to discriminate aversive from neutral sight stimuli was 92% (specificity = 92%, sensitivity = 92%, p = 0.001), and to discriminate aversive from appetitive sight stimuli was 63.5% (specificity = 73%, sensitivity = 54%, p = 0.009).

Conclusions

Our results demonstrate the predictive value of neurofunctional data in discriminating emotional and neutral networks of activity in the healthy human brain. It would be of interest to use pattern recognition techniques and fMRI to examine network dysfunction in the processing of appetitive, aversive and neutral stimuli in psychiatric disorders. Especially where problems with reward and punishment processing have been implicated in the pathophysiology of the disorder.

The neural basis of sex differences in sexual behavior: A quantitative meta-analysis

Sexuality as to its etymology presupposes the duality of sexes. Using quantitative neuroimaging meta-analyses, we demonstrate robust sex differences in the neural processing of sexual stimuli in thalamus, hypothalamus, and basal ganglia. In a narrative review, we show how these relate to the well-established sex differences on the behavioral level. More specifically, we describe the neural bases of known poor agreement between self-reported and genital measures of female sexual arousal, of previously proposed male proneness to affective sexual conditioning, as well as hints of unconscious activation of bonding mechanisms during sexual stimulation in women. In summary, our meta-analytic review demonstrates that neurofunctional sex differences during sexual stimulation can account for well-established sex differences in sexual behavior.

Paroxetine Treatment of Problematic Pornography Use: A Case Series

Background How best to conceptualize problematic pornography use (PPU) and intervene most effectively remain debated, with obsessive-compulsive disorder (OCD) and addiction frameworks. We investigated the efficacy of the serotonin-reuptake inhibitor paroxetine in combination with cognitive-behavioral therapy in the treatment of problematic pornography use (PPU). Case presentation Three heterosexual males with PPU were treated with cognitive-behavioral therapy and paroxetine. Frequency of pornography use, other sexual behaviors, and anxiety were assessed during treatment. Discussion Paroxetine treatment, although seemingly initially effective in reducing pornography use and anxiety, appeared related to new compulsive sexual behaviors after 3 months. Conclusions Paroxetine may hold promise for short-term reduction of PPU and related anxiety, but new potentially distressing sexual behaviors may emerge. The cases suggest that PPU may arise from multiple domains. We propose an explanation of the effects based on recent neuroscientific research on sexual behaviors and alcohol use.

Serotonergic antidepressants decrease hedonic signals but leave learning signals in the nucleus accumbens unaffected

Investigating the effects of serotonergic antidepressants on neural correlates of visual erotic stimulation revealed decreased reactivity within the dopaminergic reward network along with decreased subjective sexual functioning compared with placebo. However, a global dampening of the reward system under serotonergic drugs is not intuitive considering clinical observations of their beneficial effects in the treatment of depression. Particularly, learning signals as coded in prediction error processing within the dopaminergic reward system can be assumed to be rather enhanced as antidepressant drugs have been demonstrated to facilitate the efficacy of psychotherapeutic interventions relying on learning processes. Within the same study sample, we now explored the effects of serotonergic and dopaminergic/noradrenergic antidepressants on prediction error signals compared with placebo by functional MRI. A total of 17 healthy male participants (mean age: 25.4 years) were investigated under the administration of paroxetine, bupropion and placebo for 7 days each within a randomized, double-blind, within-subject cross-over design. During functional MRI, we used an established monetary incentive task to explore neural prediction error signals within the bilateral nucleus accumbens as region of interest within the dopaminergic reward system. In contrast to diminished neural activations and subjective sexual functioning under the serotonergic agent paroxetine under visual erotic stimulation, we revealed unaffected or even enhanced neural prediction error processing within the nucleus accumbens under this antidepressant along with unaffected behavioural processing. Our study provides evidence that serotonergic antidepressants facilitate prediction error signalling and may support suggestions of beneficial effects of these agents on reinforced learning as an essential element in behavioural psychotherapy.

Enhanced neural response to anticipation, effort and consummation of reward and aversion during bupropion treatment

BACKGROUND

We have previously shown that the selective serotonergic reuptake inhibitor, citalopram, reduces the neural response to reward and aversion in healthy volunteers. We suggest that this inhibitory effect might underlie the emotional blunting reported by patients on these medications. Bupropion is a dopaminergic and noradrenergic reuptake inhibitor and has been suggested to have more therapeutic effects on reward-related deficits. However, how bupropion affects the neural responses to reward and aversion is unclear.

METHOD

Seventeen healthy volunteers (9 female, 8 male) received 7 days bupropion (150 mg/day) and 7 days placebo treatment, in a double-blind crossover design. Our functional magnetic resonance imaging task consisted of three phases; an anticipatory phase (pleasant or unpleasant cue), an effort phase (button presses to achieve a pleasant taste or to avoid an unpleasant taste) and a consummatory phase (pleasant or unpleasant tastes). Volunteers also rated wanting, pleasantness and intensity of the tastes.

RESULTS

Relative to placebo, bupropion increased activity during the anticipation phase in the ventral medial prefrontal cortex (vmPFC) and caudate. During the effort phase, bupropion increased activity in the vmPFC, striatum, dorsal anterior cingulate cortex and primary motor cortex. Bupropion also increased medial orbitofrontal cortex, amygdala and ventral striatum activity during the consummatory phase.

CONCLUSIONS

Our results are the first to show that bupropion can increase neural responses during the anticipation, effort and consummation of rewarding and aversive stimuli. This supports the notion that bupropion might be beneficial for depressed patients with reward-related deficits and blunted affect.

Baseline Perfusion Alterations Due to Acute Application of Quetiapine and Pramipexole in Healthy Adults

BACKGROUND

The dopaminergic system is implicated in many mental processes and neuropsychiatric disorders. Pharmacologically, drugs with dopamine receptor antagonistic and agonistic effects are used, but their effects on functional brain metabolism are not well known.

METHODS

In this randomized crossover, placebo-controlled, and rater-blinded study, 25 healthy adults received an acute dose placebo substance (starch), quetiapine (dopamine receptor antagonist), or pramipexole (dopamine agonist of the nonergoline class) 1 hour before the experiment. Background-suppressed 2D pseudo-continuous arterial spin labeling was used to examine whole-brain baseline cerebral blood flow differences induced by the 3 substances.

RESULTS

We found that quetiapine reduced perfusion in the occipital (early visual areas) and bilateral cerebellar cortex relative to placebo. In contrast, quetiapine enhanced cerebral blood flow (relative to placebo) in the striatal system (putamen and caudate nucleus) but also in the supplementary motor area, insular-, prefrontal- as well as in the pre- and postcentral cortex. Pramipexole increased cerebral blood flow compared with placebo in the caudate nucleus, putamen, middle frontal, supplementary motor area, and brainstem (substantia nigra), but reduced cerebral blood flow in the posterior thalamus, cerebellum, and visual areas. Pramipexole administration resulted in stronger cerebral blood flow relative to quetiapine in the hypothalamus, cerebellum, and substantia nigra.

CONCLUSIONS

Our results indicate that quetiapine and pramipexole differentially modulate regional baseline cerebral blood flow. Both substances act on the dopaminergic system, although they affect distinct regions. Quetiapine altered dopaminergic function in frontal, striatal, and motor regions. In contrast, pramipexole affected cerebral blood flow of the nigrostriatal (striatum and substantia nigra) dopaminergic, but less the fronto-insular system.

Paroxetine-The Antidepressant from Hell? Probably Not, But Caution Required

Paroxetine, also known by the trade names Aropax, Paxil, Pexeva, Seroxat, Sereupin and Brisdelle, was first marketed in the U.S. in 1992. Effective for major depression and various anxiety disorders, it quickly gained a sizable share of the antidepressant prescription market. By the late 1990s, paroxetine frequently was being associated with serious drug interactions and medication side effects. Most significantly, in a major Canadian epidemiological study examining the relationship between antidepressants and diseases, paroxetine was associated with a 620 percent increase in the rate of breast cancer in women who had taken it over a four-year period. Though re-analyses of this investigation discounted the magnitude of these findings, other studies have associated paroxetine with numerous side effects and adverse events not reported in clinical trials. Among these are effects on male fertility, birth defects, gestational hypertension, prolonged QT interval in infants, hyperprolactinemia, cognitive impairment in the elderly, autism, sexual side effects, weight gain, and suicidality, aggression, and akathisia in children and adolescents. Paroxetine has the highest inhibitory constant for the P450 2D6 isoenzyme of all antidepressants (Ki = 0.065-4.65 micromoles). This high affinity explains its high inhibitory interaction profile with substrates for 2D6. Paroxetine's potent 2D6 inhibition also implies that significant inhibition of the metabolism of 2D6 carcinogen substrates occurs which implies an increased probability of oncogenesis. Through 2D6 inhibition, tamoxifen metabolism is inhibited, which has been found to increase the risk of dying from breast cancer over a five-year period in women on both medications. Paroxetine also is a potent inhibitor of 3A4 with multiple 3A4 substrate interactions. Paroxetine has the highest known affinity for the serotonin transporter (0.13 nanomoles) of any currently used antidepressant. These characteristics and their potential negative consequences along with other adverse effects are considered and weighed against paroxetine's efficacious antidepressant and anxiolytic effects.

Sexual Function Across Aging

Women experience multiple changes in social and reproductive statuses across the life span which can affect sexual functioning. Various phases of the sexual response cycle may be impacted and can lead to sexual dysfunction. Screening for sexual problems and consideration of contributing factors such as neurobiology, reproductive life events, medical problems, medication use, and depression can help guide appropriate treatment and thereby improve the sexual functioning and quality of life of affected women. Treatment options include psychotropic medications, hormone therapy, and psychotherapy.

Impact of Antidepressant Drugs on Sexual Function and Satisfaction

Pleasurable sexual activity is important in many human relationships and can provide a sense of physical, emotional and social well-being. Depressive symptoms and depressive illness are associated with impairments in sexual function and sexual dissatisfaction in untreated and treated patients. Most currently available antidepressant drugs are associated with development or worsening of sexual dysfunction in a substantial proportion of patients. Sexual difficulties during antidepressant treatment often resolve as depression lifts, but can persist over long periods, reducing self-esteem and affecting mood and relationships adversely. Sexual difficulties during antidepressant treatment typically have many possible causes but the incidence and nature of dysfunction varies between drugs. Many interventions can be considered when managing sexual dysfunction associated with antidepressants but no approach is 'ideal'. Because treatment-emergent sexual difficulties are less frequent with certain drugs, presumably related to differences in pharmacological properties, and since current interventions are suboptimal, a lower incidence of sexual dysfunction is a relevant tolerability target when developing novel antidepressants.

Sexual side-effects of antidepressant and antipsychotic drugs

PURPOSE OF REVIEW

Psychotropic-related sexual dysfunction is a quite frequent issue in clinical practice, mainly in chronic treatments affecting both quality of life and compliance.

RECENT FINDINGS

In the last decade fortunately antidepressants and antipsychotic compounds have been deeply screened in order to identify sexual adverse events that were commonly underdiagnosed and previously underestimated by clinicians and perhaps by pharmaceutical companies as well. Some differences in the mechanism of action are the nucleus of this poorly tolerated adverse event. All antidepressants with serotonergic activity can cause mild to severe sexual dysfunction such as decreased libido and delayed orgasm frequently (>60%) or anorgasmia and arousal difficulties sometimes (30%). In contrast, noradrenergic, dopaminergic, or melatonergic antidepressants do not cause sexual dysfunction but perhaps the clinical profile of patients receiving these compounds could be different. Antipsychotics that highly increase prolactin levels and strongly block dopamine receptors could be related to sexual dysfunction as well. Unfortunately, these dysfunctions are present during the long term after the antipsychotic onset to provide continued symptom control and enable recovery. Young patients suffering psychosis and concomitant sexual dysfunction (erectile and/or orgasmic difficulties) tend to show poor compliance in chronic treatments affecting the outcomes.

SUMMARY

The implications of psychotropic-related sexual dysfunction in clinical practice are relevant mainly in patients under long-term treatment with previous satisfactory sexual life. Implications for future research about sexual dysfunction in all new treatments should be strongly taken into account.

Better sexual acceptability of agomelatine (25 and 50 mg) compared to escitalopram (20 mg) in healthy volunteers. A 9-week, placebo-controlled study using the PRSexDQ scale

The present double-blind, placebo-controlled study evaluates the effects of agomelatine and the selective serotonin reuptake inhibitor escitalopram on sexual dysfunction in healthy men and women.

METHODS

A total of 133 healthy volunteers (67 men, 66 women) were randomly assigned to agomelatine (25 or 50 mg) or escitalopram (20 mg) or placebo for nine weeks. Sexual acceptability was evaluated by using the psychotropic-related sexual dysfunction questionnaire 5-items total score and sexual dysfunction relative to each sub-score (in 110 volunteers with sexual activity). Sexual dysfunction was evaluated at baseline and after two, five and eight weeks of treatment and one week after drug discontinuation.

RESULTS

The psychotropic-related sexual dysfunction questionnaire 5-items total score was significantly lower in both agomelatine groups versus escitalopram at all visits (p < 0.01 to p < 0.0001) with no difference between agomelatine and placebo nor between both agomelatine doses. Similar results were observed after drug discontinuation. The total score was significantly higher in the escitalopram group than in the placebo group at each post-baseline visit (p < 0.01 to p < 0.001). Similar results were observed regardless of volunteers' gender. Compared to placebo, only escitalopram significantly impaired dysfunction relative to "delayed orgasm or ejaculation" (p < 0.01) and "absence of orgasm or ejaculation" (p < 0.05 to p < 0.01). The percentage of participants with a sexual dysfunction was higher in the escitalopram group than in agomelatine groups (p < 0.01 to p < 0.05) and placebo (p < 0.01).

CONCLUSION

The study confirms the better sexual acceptability profile of agomelatine (25 or 50 mg) in healthy men and women, compared to escitalopram.

TRIAL REGISTRATION NAME

Evaluation of the effect of agomelatine and escitalopram on emotions and motivation in healthy male and female volunteers.

TRIAL REGISTRATION NUMBER

ISRCTN75872983.

Neural correlates of successful psychotherapy of depression in adolescents

BACKGROUND

While major effort has been put in investigating neural correlates of depression and its treatment in adults, less is known about the effects of psychotherapy in adolescents. Given the concordance of the ventral striatum, amygdala, hippocampus and the subgenual anterior cingulate cortex (sgACC) as correlates of depression and their involvement in reward processing, we used functional magnetic resonance imaging (fMRI) during performance of a monetary reward task in an intervention versus waitlist-control design to investigate the clinical and neural effects of cognitive behavioral group therapy (CBT-G).

METHODS

22 medication naïve adolescents with major depressive disorder were scanned before and after five sessions of CBT-G (PAT-I), or before and after five weeks of waiting (PAT-W). Changes in symptom scales were analyzed along with neural activation changes within the amygdala, hippocampus, sgACC and ventral striatum regions of interest (ROI).

RESULTS

Psychometric assessments and ROI activation remained unchanged in PAT-W. In PAT-I, significant reduction in clinical symptoms accompanied significant changes in brain activation within the left amygdala, left hippocampus and bilateral sgACC. In line with previous findings in adults, pre-to-post-activation changes in the bilateral sgACC correlated with pre-to-post and pre-to-follow-up symptom improvement, and individual expressions of sgACC activation before treatment were related to pre-to-follow-up therapeutic success.

LIMITATIONS

Future studies should include larger sample sizes.

CONCLUSIONS

Successful group psychotherapy of depression in adolescents was related to signal changes in brain regions previously demonstrated to be reliably linked with successful, particularly pharmacological treatment in adults.

Local and Global Resting State Activity in the Noradrenergic and Dopaminergic Pathway Modulated by Reboxetine and Amisulpride in Healthy Subjects

BACKGROUND

Various psychiatric populations are currently investigated with resting state fMRI, with the aim of individualizing diagnostics and treatment options and improving treatment outcomes. Many of these studies are conducted in large naturalistic samples, providing rich insights regarding disease-related neural alterations, but with the common psychopharmacological medication limiting interpretations of the results. We therefore investigated the effects of common noradrenergic and anti-dopaminergic medications on local and global resting state activity (rs-activity) in healthy volunteers to further the understanding of the respective effects independent from disease-related alterations.

METHODS

Within a randomized, double-blind, placebo-controlled crossover design, we investigated 19 healthy male subjects by resting state fMRI after the intake of reboxetine (4 mg/d), amisulpride (200mg/d), and placebo for 7 days each. Treatment-related differences in local and global rs-activity were measured by the fractional amplitude of low frequency fluctuations (fALFF) and resting state functional connectivity (rs-FC).

RESULTS

fALFF revealed alterations of local rs-activity within regions of the core noradrenergic pathway, including the locus coeruleus under reboxetine, correlated with its plasma levels. Moreover, reboxetine led to increased rs-FC between regions within this pathway, i.e. the locus coeruleus, tectum, thalamus, and amygdala. Amisulpride modulated local rs-activity of regions within the dopaminergic pathway, with the altered signal in the putamen correlating with amisulpride plasma levels. Correspondingly, amisulpride increased rs-FC between regions of the dopaminergic pathway comprising the substantia nigra and putamen.

CONCLUSION

Our data provide evidence of how psychopharmacological agents alter local and global rs-activity within the respective neuroanatomical pathways in healthy subjects, which may help with interpreting data in psychiatric populations.

Effect of Cytochrome P450 polymorphism on the action and metabolism of selective serotonin reuptake inhibitors

INTRODUCTION

The aim of this article is to review the field of clinically relevant pharmacogenetic effects of cytochrome P450 polymorphisms on metabolism, kinetics, and action of selective serotonin reuptake inhibitors (SSRIs).

AREAS COVERED

The relevant literature in humans on the implications of genetic variation on SSRI drug exposure, drug safety, and efficacy was systematically evaluated. There is a large amount of evidence on the influences of CYP polymorphisms on the pharmacokinetics of SSRIs. Regulatory agencies have issued warnings or advice considering dose adjustments in the presence of affected metabolic phenotypes for several SSRIs. Evidence-based dose adjustments for drugs dependent on CYP genotype are available to clinicians. However, few data on the relationship between genetically determined elevated plasma concentrations of SSRIs and specific side effects or therapeutic failure are currently available.

EXPERT OPINION

Genetic polymorphisms in CYP2D6 and CYP2C19 exert large influences on the individual exposure to SSRIs, leading to the aim to achieve similar concentration time courses in different metabolizer phenotypes. The implementation of a stratified approach to medication with SSRIs in different metabolic phenotypes on a rational basis will require new studies assessing the association between clinical outcomes (such as adverse reactions) and genetically determined elevated plasma concentrations.

Effect of anti-somatization therapy on quality of life in patients with functional dyspepsia

AIM: To observe somatic symptoms of patients with functional dyspepsia (FD) and assess the effect of anti-somatization therapy on the quality of life in patients with FD.

METHODS: One hundred patients with FD were included in the study, and they were divided into an observation group and a control group. Patients in the control group were treated with conventional proton pump inhibitors (PPI) and/or prokinetics. Patients in the observation group were given anti-somatization therapy. The somatic symptoms and Nepean dyspepsia index (NDI) were compared after 4 wk of treatment.

RESULTS: The total effective rate was significantly higher in the observation group than in the control group (92.0% vs 70.0%, P < 0.05). PHQ-15 score after treatment in the observation group was significantly lower than that before treatment (P < 0.05). There was no significant difference in PHQ-15 score in the control group before and after treatment (P > 0.05). As the treatment time extended, NDI score was improved in both groups, and the improvement was more significant in the observation group (P < 0.05). NDI score at 2-4 wk after treatment in the observation group was significantly lower than that in the control group (P < 0.05).

CONCLUSION: The quality of life in patients with FD is affected by somatic symptoms. For FD patients with poor response to conventional treatment, the quality of life could be improved by the combination of anti-somatization therapy and conventional therapy.

Erotic stimulus processing under amisulpride and reboxetine: a placebo-controlled fMRI study in healthy subjects

BACKGROUND

Impaired sexual function is increasingly recognized as a side effect of psychopharmacological treatment. However, underlying mechanisms of action of the different drugs on sexual processing are still to be explored. Using functional magnetic resonance imaging, we previously investigated effects of serotonergic (paroxetine) and dopaminergic (bupropion) antidepressants on sexual functioning (Abler et al., 2011). Here, we studied the impact of noradrenergic and antidopaminergic medication on neural correlates of visual sexual stimulation in a new sample of subjects.

METHODS

Nineteen healthy heterosexual males (mean age 24 years, SD 3.1) under subchronic intake (7 days) of the noradrenergic agent reboxetine (4 mg/d), the antidopaminergic agent amisulpride (200mg/d), and placebo were included and studied with functional magnetic resonance imaging within a randomized, double-blind, placebo-controlled, within-subjects design during an established erotic video-clip task. Subjective sexual functioning was assessed using the Massachusetts General Hospital-Sexual Functioning Questionnaire.

RESULTS

Relative to placebo, subjective sexual functioning was attenuated under reboxetine along with diminished neural activations within the caudate nucleus. Altered neural activations correlated with decreased sexual interest. Under amisulpride, neural activations and subjective sexual functioning remained unchanged.

CONCLUSIONS

In line with previous interpretations of the role of the caudate nucleus in the context of primary reward processing, attenuated caudate activation may reflect detrimental effects on motivational aspects of erotic stimulus processing under noradrenergic agents.