Total testosterone, androgen receptor polymorphism, and depressive symptoms in young black and white men: the CARDIA Male Hormone Study

Effects of testosterone dose on depression-like behavior among castrated adult male rats

Previous research has shown a decrease in serum testosterone levels in male patients with depression. In recent years, the results of testosterone replacement therapy (TRT) to improve depression have been mixed. Using the classic CUMS model, we induced depressive-like behaviors in rats and observed a decrease in their serum testosterone levels along with an increase in androgen receptor expression in the hippocampus. We then performed castration and sham surgery on male rats and found that testosterone deprivation led to the manifestation of depressive-like behavior that could be ameliorated by TRT. Through a repeated measures experiment consisting of five blocks over a period of 25 days, we discovered that the reduction in depressive-like behavior in testosterone-deprived rats began 22 days after drug administration (0.5 and 0.25 mg/rat). Furthermore, rats in 0.5mgT group showed the most significant improvements. Subsequently, this dose was used in CUMS rats and reduced the occurrence of depressive-like behaviors. Our study has demonstrated the complex interplay between depression and testosterone, as well as the intricate dose-response relationship between TRT and reduction in depression. Our research supports the use of TRT to alleviate depression, but dosage and duration of treatment are critical factors in determining efficacy.

Hair androgen concentrations and depressive disorders in adolescents from the general population

Although the link between androgens and depression is well established in adults, the effects of cofactors on this association are less clearly understood, particularly in youth. Epidemiological cohort study of adolescents in Dresden, Germany. Analyses comprised data of 985 individuals assessed at baseline and of 512 individuals at 1-year follow-up. We investigated multivariable regression models for cross-sectional and longitudinal associations of hair testosterone, dehydroepiandrosterone (DHEA), and their cortisol ratios with 12-month diagnoses of major depressive disorder (MDD) and MDD without any anxiety disorder assessed with standardized diagnostic interview (DIA-X-5), and with dimensional depression scores (PHQ-9, PROMIS), separately for males and females. The potential moderating effect of social support was determined. Cross-sectional analyses yielded inverse associations of testosterone and DHEA with MDD and MDD without any anxiety disorders in males. In cross-sectional and longitudinal analyses, baseline ratio cortisol/DHEA was significantly, inversely associated to PROMIS-depression in males. Only cross-sectional associations for ratio cortisol/DHEA and PROMIS-depression remained significant after Bonferroni-Holm correction. No robust associations were observed in female participants. Social support exerted no consistent moderating effect on the investigated association. The present observational cohort study showed no consistent association of hair androgen concentrations with depressive disorders in adolescents. However, findings provide some support for the association between the cortisol/DHEA ratio and depression in males. Longitudinal research designs in large samples are needed to understand the interplay between androgens, depression, and developmental and social factors in youth.

The role of testosterone, the androgen receptor, and hypothalamic-pituitary-gonadal axis in depression in ageing Men

Considerable research has shown that testosterone regulates many physiological systems, modulates clinical disorders, and contributes to health outcome. However, studies on the interaction of testosterone levels with depression and the antidepressant effect of testosterone replacement therapy in hypogonadal men with depression have been inconclusive. Current findings indicate that low circulating levels of total testosterone meeting stringent clinical criteria for hypogonadism and testosterone deficiency induced by androgen deprivation therapy are associated with increased risk for depression and current depressive symptoms. The benefits of testosterone replacement therapy in men with major depressive disorder and low testosterone levels in the clinically defined hypogonadal range remain uncertain and require further investigation. Important considerations going forward are that major depressive disorder is a heterogeneous phenotype with depressed individuals differing in inherited polygenic determinants, onset and clinical course, symptom complexes, and comorbidities that contribute to potential multifactorial differences in pathophysiology. Furthermore, polygenic mechanisms are likely to be critical to the biological heterogeneity that influences testosterone-depression interactions. A genetically informed precision medicine approach using genes regulating testosterone levels and androgen receptor sensitivity will likely be essential in gaining critical insight into the role of testosterone in depression.

Size Matters: The CAG Repeat Length of the Androgen Receptor Gene, Testosterone, and Male Adolescent Depression Severity

There is a distinct increase in the prevalence of depression with the onset of puberty. The role of peripubertal testosterone levels in boys in this context is insufficiently understood and may be modulated by a functional polymorphism of the androgen receptor gene (AR), a variable number of CAG repeats. Moreover, there is preliminary evidence that the relationship between testosterone, CAG repeat length, and the severity of depressive symptoms may differ between subclinical and overt depression, but this has neither been studied in a clinical sample of adolescents with depression nor compared between subclinical and overt depression in an adequately powered study. To investigate the relationship between free testosterone, CAG repeat length of the AR, depression status (subclinical vs. overt), and the severity of depressive symptoms, 118 boys treated as in- or daycare patients at a single psychiatric hospital were studied. Of these, 73 boys had at least mild depressive symptoms according to the Beck Depression Inventory-II (BDI-II > 13). Higher-order moderation analysis in the multiple regression framework revealed a constant relationship between free testosterone and depression severity irrespective of the number of CAG repeats in adolescents with a BDI-II score ≤ 13. In adolescents with a BDI-II score > 13, however, there was a significant negative relationship between free testosterone and BDI-II score in patients with <19 CAG repeats and a significant positive relationship regarding free testosterone and BDI-II score in those with more than 28 CAG repeats, even when considering important covariates. These results suggest that the effects of testosterone on mood in male adolescents with depression depend on the genetic make-up of the AR as well as on depression status. This complex relationship should be considered by future studies addressing mental health issues against an endocrine background and may, moreover, contribute to tailored treatment concepts in psychiatric medicine, especially in adults.

Genetic Variation in the Androgen Receptor Modifies the Association Between Testosterone and Vitality in Middle-Aged Men

BACKGROUND

Low vitality is a common symptom of testosterone deficiency; however, clinical trial results remain inconclusive regarding the responsiveness of this symptom to hormone replacement.

AIM

The aim of the present study was to determine if the relationship between circulating testosterone levels and vitality would be moderated by the CAG repeat length in the androgen receptor (AR) gene, which influences the receptor's sensitivity to testosterone.

METHODS

We examined 676 men in the Vietnam Era Twin Study of Aging when they were, on average, 55.4 years old (SD = 2.5). Salivary testosterone levels were measured by using 3 samples collected at waking on 3 nonconsecutive days. The average testosterone level was classified as low, normal, or high based on 1-SD cutoffs. Analyses were conducted using multilevel, mixed linear models, which accounted for the nonindependence of the twin data, and adjusted for the effects of age, ethnicity, BMI, chronic health conditions, depressive symptoms, and sleep quality.

OUTCOMES

Vitality was measured using the 36-item Short Form (SF-36) vitality subscale.

RESULTS

We observed a significant interaction between salivary testosterone and the AR-CAG repeat length. When the repeat length was short, men with low testosterone had significantly lower vitality. As the AR-CAG repeat length increased, the magnitude of the testosterone effect decreased.

CLINICAL TRANSLATION

The observed interaction between testosterone and variation in the AR gene suggests that men with more sensitive ARs, as indicated by a shorter AR-CAG repeat, are more likely to experience symptoms of age-related testosterone deficiency.

STRENGTHS & LIMITATIONS

Strengths of the present study include our use of a large community-based sample, the use of multiple testosterone measurements, and the availability of a comprehensive set of covariates that may impact the association of interest. Limitations include the homogeneous nature of the sample with respect to ethnicity, the brevity of the 36-item Short Form vitality subscale, and our inability to establish change in testosterone levels because of the cross-sectional nature of data.

CONCLUSIONS

The association between testosterone and vitality appears to be clinically meaningful and is in part dependent on variation in the AR gene. Panizzon MS, Bree K, Hsieh T-C, et al. Genetic Variation in the Androgen Receptor Modifies the Association Between Testosterone and Vitality in Middle-Aged Men. J Sex Med 2020;17:2351-2361.

Repeat length variations in polyglutamine disease-associated genes affect body mass index

BACKGROUND

The worldwide prevalence of obesity, a major risk factor for numerous debilitating chronic disorders, is increasing rapidly. Although a substantial amount of the variation in body mass index (BMI) is estimated to be heritable, the largest meta-analysis of genome-wide association studies (GWAS) to date explained only ~2.7% of the variation. To tackle this 'missing heritability' problem of obesity, here we focused on the contribution of DNA repeat length polymorphisms which are not detectable by GWAS.

SUBJECTS AND METHODS

We determined the cytosine-adenine-guanine (CAG) repeat length in the nine known polyglutamine disease-associated genes (ATXN1, ATXN2, ATXN3, CACNA1A, ATXN7, TBP, HTT, ATN1 and AR) in two large cohorts consisting of 12,457 individuals and analyzed their association with BMI, using generalized linear mixed-effect models.

RESULTS

We found a significant association between BMI and the length of CAG repeats in seven polyglutamine disease-associated genes (including ATXN1, ATXN2, ATXN3, CACNA1A, ATXN7, TBP and AR). Importantly, these repeat variations could account for 0.75% of the total BMI variation.

CONCLUSIONS

Our findings incriminate repeat polymorphisms as an important novel class of genetic risk factors of obesity and highlight the role of the brain in its pathophysiology.

Does Calculated Free Testosterone Overcome Total Testosterone in Protecting From Sexual Symptom Impairment? Findings of a Cross-Sectional Study

BACKGROUND

Although erectile dysfunction (ED) has been associated with low circulating total testosterone (TT) levels, the utility of free testosterone (FT) over TT is debatable.

AIM

To assess the relative impact of low TT and low calculated FT (cFT) on androgen-related sexual symptoms in men with ED.

METHODS

Data from 485 men were analyzed. Comorbidities were scored with the Charlson Comorbidity Index (CCI). Patients completed the International Index of Erectile Function (IIEF) and the Beck Inventory for Depression (BDI). Descriptive statistics tested differences between patients with normal TT levels (>3 ng/mL) and normal cFT levels (>65 pg/mL; group 1) and men with normal TT and low cFT (group 2), low TT and normal cFT (group 3), and low TT and low cFT (group 4). Linear regression models tested the association between clinical predictors and sexual function impairment.

OUTCOMES

We assessed the impact of different hormonal categories on androgen-related symptoms and the clinical utility of measuring cFT in men with ED.

RESULTS

Groups 1, 2, 3, and 4 were composed of 338 (69.6%), 44 (9.1%), 34 (7.0%), and 69 (14.3%) patients, respectively. Compared with group 1, patients in group 2 were older (P < .001), had a higher body mass index (P < .01), and had a larger proportion with CCI scores of at least 1 (P = .006). Likewise, group 2 presented lower scores for the IIEF erectile function (P = .07), sexual desire (P = .04), and orgasmic function (P = .007) domains and lower BDI scores (P = .02) than group 1. Similar findings were found for group 4 vs 1. Conversely, patients in group 3 had similar scores on the questionnaires to those in group 1. Low cFT and normal or low TT achieved independent predictor status for pathologic IIEF domains and BDI scores after accounting for age, CCI, and body mass index. Conversely, low TT and normal cFT status was not associated with pathologic scores on the questionnaires.

CLINICAL IMPLICATIONS

The inclusion of cFT in the first-line assessment of hypogonadal symptoms in men with ED has major clinical utility.

STRENGTHS AND LIMITATIONS

This is the first study evaluating the concomitant impact of TT and cFT on men with ED using well-validated instruments to assess patients' sexuality and depressive symptoms. Limitations are the retrospective nature of the study and lack of physical function data and bone ultrasound measurements.

CONCLUSIONS

Although normal cFT was not associated with signs and symptoms suggestive of testosterone deficiency, even when concomitant with low TT or low cFT irrespective of TT values, it was indicative of poorer clinical profiles and impaired sexual and depressive parameters compared with normal TT and normal cFT in a cohort of patients with ED. Boeri L, Capogrosso P, Ventimiglia E, et al. Does Calculated Free Testosterone Overcome Total Testosterone in Protecting From Sexual Symptom Impairment? Findings of a Cross-Sectional Study. J Sex Med 2017;14:1549-1557.

Polymorphisms in sex steroid receptors: From gene sequence to behavior

Sex steroid receptors have received much interest as potential mediators of human behaviors and mental disorders. Candidate gene association studies have identified about 50 genetic variants of androgen and estrogen receptors that correlate with human behavioral phenotypes. Because most of these polymorphisms lie outside coding regions, discerning their effect on receptor function is not straightforward. Thus, although discoveries of associations improve our ability to predict risk, they have not greatly advanced our understanding of underlying mechanisms. This article is intended to serve as a starting point for psychologists and other behavioral biologists to consider potential mechanisms. Here, I review associations between polymorphisms in sex steroid receptors and human behavioral phenotypes. I then consider ways in which genetic variation can affect processes such as mRNA transcription, splicing, and stability. Finally, I suggest ways that hypotheses about mechanism can be tested, for example using in vitro assays and/or animal models.

Testosterone and depressive symptoms among men in the Diabetes Prevention Program

OBJECTIVE

We examined associations between intensive lifestyle intervention (ILS) and changes in testosterone and associations with mood among middle-aged men.

DESIGN

Secondary analysis of men (n=886) participating in the Diabetes Prevention Program which randomized glucose-intolerant, overweight men to ILS, metformin, or placebo between 1996 and 1999.

MAIN OUTCOME MEASURES

Changes in testosterone between baseline and 1-year follow-up asnd associations of these changes with mood measures (Beck Depression Inventory [BDI-II], Beck Anxiety Inventory [BAI]).

RESULTS

Median baseline testosterone was 10.98nmol/l and 44% (n=385) had testosterone<10.41nmol/l or 300ng/dl. Testosterone increases were greater among men randomized to ILS vs. metformin vs. placebo (1.15nmol/l vs. -0.12nmol/l vs. -0.27nmol/l, p<0.001). The association between changes in testosterone and mood differed by study arm (p<0.001 for interaction); there were no significant associations between changes in testosterone and mood changes among men in the ILS or placebo arms. Among men in the metformin arm, increases in testosterone were significantly associated with decreases in BDI-II (improved depressive symptoms) (β-coefficient -0.2336, p=0.0002) indicating a 0.23 decrease in BDI-II for every 1nmol/l increase in testosterone and decreases in BAI (improved anxiety symptoms) (β-coefficient -0.2147, p=0.0014). Similar patterns were observed for bioavailable testosterone.

CONCLUSIONS

Among overweight middle-aged men with glucose-intolerance, ILS increased endogenous testosterone slightly but without significant improvements in mood. Metformin did not increase testosterone, but among metformin users, testosterone increases were associated with improvements in mood. Thus, interventions that increase endogenous testosterone may not also improve mood.

Pharmacogenetics of erectile dysfunction: navigating into uncharted waters

Sildenafil and other PDE-5 inhibitors have revolutionized erectile dysfunction (ED) treatment. However, a significant number of patients do not respond or present adverse reactions to these drugs. While genetic polymorphisms may underlie this phenomenon, very little research has been undertaken in this research field. Most of the current knowledge is based on sildenafil, thus almost completely ignoring other important pharmacological therapies. Currently, the most promising genes with pharmacogenetic implications in ED are related to the nitric oxide and cGMP pathway, although other genes are likely to affect the responsiveness to treatment of ED. Nevertheless, the small number of studies available opens the possibility of further exploring other genes and phenotypes related to ED. This article provides a comprehensive overview of the genes being tested for their pharmacogenetic relevance in the therapy of ED.

Social deficits induced by peripubertal stress in rats are reversed by resveratrol

Adolescence is increasingly recognized as a critical period for the development of the social system, through the maturation of social competences and of their underlying neural circuitries. The present study sought to test the utility of resveratrol, a dietary phenol recently reported to have mood lifting properties, in modulating social interaction that is deficient following early life adversity. The main aims were to 1) pharmacologically restore normative social investigation levels dampened by peripubertal stress in rats and 2) identify neural pathways engaged by this pharmacological approach. Following peripubertal (P28-42) stress consisting of unpredictable exposures to fearful experiences, at adulthood the subjects' propensity for social exploration was examined in the three-chamber apparatus, comparing time invested in social or non-social investigation. Administered intraperitoneally 30 min before testing, resveratrol (20 mg/kg) normalized the peripubertal stress-induced social investigation deficit seen in the vehicle group, selectively altering juvenile but not object exploration. Examination of prefrontal cortex subregion protein samples following acute resveratrol treatment in a separate cohort revealed that while monoamine oxidase A (MAOA) enzymatic activity remained unaltered, nuclear AKT activation was selectively increased in the infralimbic cortex, but not in the prelimbic or anterior cingulate cortex. In contrast, androgen receptor nuclear localization was increased in the prelimbic cortex, but not in the infralimbic or anterior cingulate cortex. This demonstration that social contact deficits are reversed by resveratrol administration emphasizes a prosocial role for this dietary phenol, and evokes the possibility of developing new treatments for social dysfunctions.

Hormonal changes and their impact on cognition and mental health of ageing men

Demographic changes resulting in ageing of the world's population have major implications for health. As men grow older, circulating levels of the principal androgen or male sex hormone testosterone (T) decline, while the prevalence of ill-health increases. Observational studies in middle-aged and older men have shown associations between lower levels of T and poorer mental health in older men, including worse cognitive performance, dementia and presence of depressive symptoms. The role of T metabolites, the more potent androgen dihydrotestosterone (DHT) and the oestrogen receptor ligand estradiol (E2) in the pathophysiology of cognitive decline are unclear. Studies of men undergoing androgen deprivation therapy in the setting of prostate cancer have shown subtle detrimental effects of reduced T levels on cognitive performance. Randomised trials of T supplementation in older men have been limited in size and produced variable results, with some studies showing improvement in specific tests of cognitive function. Interventional data from trials of T therapy in men with dementia are limited. Lower levels of T have also been associated with depressive symptoms in older men. Some studies have reported an effect of T therapy to improve mood and depressive symptoms in men with low or low-normal T levels. T supplementation should be considered in men with a diagnosis of androgen deficiency. Beyond this clinical indication, further research is needed to establish the benefits of T supplementation in older men at risk of deteriorating cognition and mental health.

The relation between sex hormone levels, the androgen receptor CAGn-polymorphism and depression and mortality in older men in a community study

BACKGROUND

Sex hormones levels and the androgen receptor CAGn polymorphism have been shown to be involved in depressed mood in aging men. But the few prior studies found inconsistent results on the role of both factors.

METHODS

186 male participants aged ≥65 years from the community based Memory and Morbidity in Augsburg Elderly (MEMO) Study underwent a physical examination, and a medical interview including two scales (Center for Epidemiologic Studies Depression Scale (CES-D); Activities of Daily Living Scale (ADL). Testosterone, SHBG and LH levels were measured and the androgen receptor CAGn polymorphism was genotyped. χ(2), Mann-Whitney U-test, Pearson's correlations and multivariable linear and logistic regression were used in the analysis.

RESULTS

Higher depressive scores were significantly associated with higher SHBG-levels (beta coefficient 0.25, p<0.001). SHBG alone explained 8% of variance of the CES-D depression score. Mortality at 10 years follow-up was predicted by higher SHBG levels, higher ADL-scores, older age, current smoking and the depression score at baseline. This model explained 35% of the variance of mortality. The number of CAG repeats was neither related to depression scores nor to mortality.

CONCLUSIONS

We found positive associations between SHBG levels and old age male depression as well as mortality. Whether SHBG has a testosterone independent effect in this context should be investigated further.

The dominance behavioral system and psychopathology: evidence from self-report, observational, and biological studies

The dominance behavioral system (DBS) can be conceptualized as a biologically based system that guides dominance motivation, dominant and subordinate behavior, and responsivity to perceptions of power and subordination. A growing body of research suggests that problems with the DBS are evident across a broad range of psychopathologies. We begin by describing psychological, social, and biological correlates of the DBS. Extensive research suggests that externalizing disorders, mania proneness, and narcissistic traits are related to heightened dominance motivation and behaviors. Mania and narcissistic traits also appear related to inflated self-perceptions of power. Anxiety and depression are related to subordination and submissiveness, as well as a desire to avoid subordination. Models of the DBS have received support from research with humans and animals; from self-report, observational, and biological methods; and use of naturalistic and experimental paradigms. Limitations of available research include the relative lack of longitudinal studies using multiple measures of the DBS and the absence of relevant studies using diagnosed samples to study narcissistic personality disorder and bipolar disorder. We provide suggestions for future research on the DBS and psychopathology, including investigations of the potential usefulness of DBS in differentiating specific disorder outcomes, the need for more sophisticated biological research, and the value of longitudinal dynamical research. Implications of using the DBS as a tool in clinical assessment and treatment are discussed.

Testosterone levels and androgen receptor gene polymorphism predict specific symptoms of depression in young men

BACKGROUND

Testosterone (T) has been hypothesized to modulate the expression of depressive symptoms in men; however, support for this proposition is mixed.

OBJECTIVE

To investigate bioavailable T, measured from saliva, and androgen receptor gene (AR) polymorphism (the number of glutamine [CAG] repeats in exon 1 of AR) and their relation to discrete symptoms of depression in 150 men aged 17 to 27 years who varied in mood status from depressed to nondepressed.

METHODS

Participants completed the Center for Epidemiologic Studies Depression Scale and the Patient Health Questionnaire-9. Principal components analysis of the scales identified 5 factors: Negative Affect, Social/Evaluative, Cognitive, Sleep, and Appetite.

RESULTS

Across the sample as a whole, higher ratings on sleep symptoms of depression were predicted by lower T concentrations and shorter CAG lengths. The association between T, CAG length, and sleep symptoms was confirmed among the subgroup of men who reported moderate to severe depression. In this subgroup, CAG repeats and T concentrations also emerged as significant predictors of negative affect scores, with the number of CAG repeats making the primary contribution.

CONCLUSIONS

These findings suggest that androgens may influence specific symptoms of depression in men.

Androgen receptor polyglutamine repeat number: models of selection and disease susceptibility

Variation in polyglutamine repeat number in the androgen receptor (AR CAGn) is negatively correlated with the transcription of androgen-responsive genes and is associated with susceptibility to an extensive list of human disease. Only a small portion of the heritability for many of these diseases is explained by conventional SNP-based genome-wide association studies, and the forces shaping AR CAGn among humans remains largely unexplored. Here, we propose evolutionary models for understanding selection at the AR CAG locus, namely balancing selection, sexual conflict, accumulation-selection, and antagonistic pleiotropy. We evaluate these models by examining AR CAGn-linked susceptibility to eight extensively studied diseases representing the diverse physiological roles of androgens, and consider the costs of these diseases by their frequency and fitness effects. Five diseases could contribute to the distribution of AR CAGn observed among contemporary human populations. With support for disease susceptibilities associated with long and short AR CAGn, balancing selection provides a useful model for studying selection at this locus. Gender-specific differences AR CAGn health effects also support this locus as a candidate for sexual conflict over repeat number. Accompanied by the accumulation of AR CAGn in humans, these models help explain the distribution of repeat number in contemporary human populations.

Salivary testosterone: associations with depression, anxiety disorders, and antidepressant use in a large cohort study

OBJECTIVE

Low circulating levels of testosterone have been associated with major depression, but there is more limited evidence for differences in patients with anxiety disorders. The use of selective serotonin reuptake inhibitors (SSRIs) and other antidepressants is associated with sexual side effects, warranting testing for interactions with testosterone.

METHODS

Data are from 722 male and 1380 female participants of The Netherlands Study of Depression and Anxiety (NESDA), who were recruited from the community, general practice care, and specialized mental health care. Depressive and anxiety diagnoses were assessed using the DSM-IV Composite International Diagnostic Interview. To smooth the episodic secretion, the four morning saliva samples per participant and the two evening samples were pooled before testosterone analysis.

RESULTS

Morning median testosterone levels were 25.2 pg/ml in men and 16.2 pg/ml in women, with lower evening levels of 18.2 and 14.1 pg/ml, respectively. Significant determinants of testosterone levels were sex, age, time of the day, use of contraceptives, and smoking status. Female patients with a current (1-month) depressive disorder (effect size 0.29; P=0.002), generalized anxiety disorder (0.25; P=0.01), social phobia (0.30; P<0.001), and agoraphobia without panic disorder (0.30; P=0.02) had lower salivary testosterone levels than female controls. Higher testosterone levels were found in male and female participants using SSRIs than in non-users (effect size 0.26; P<0.001).

CONCLUSION

Salivary testosterone levels are lower in female patients with a depressive disorder, generalized anxiety disorder, social phobia, and agoraphobia as compared to female controls. SSRIs may increase salivary testosterone in men and women.

Relationship between depressive symptoms and hypogonadism in men with COPD

The prevalence of depression in chronic obstructive pulmonary disease (COPD) is greater than in the general population, but the mechanism is unknown. Depression has been linked mechanistically to testosterone deficiency, and testosterone deficiency (hypogonadism) affects many men with COPD. Accordingly, we hypothesized that significant depressive symptoms would be associated with hypogonadism in men with COPD. The hypothesis was tested in a prospective cross-sectional investigation of 104 men (FEV1 = 43 ± 1% predicted (± SE)), 36 of whom had significant depressive symptoms (Geriatric Depression Scale score or GDS ≥ 11). Hypogonadism was present in 14 patients with GDS ≥ 11 (39%) and in 21 with GDS < 11 (31%; p = 0.41). The independent association between depressive symptoms and gonadal state was evaluated after adjusting for potential confounders: combined severity of lung disease and functional impairment (BODE-index), co-morbidities (Charlson co-morbidity-Index), age, active smoking, education, and marital status. After controlling for confounding variables, multivariable logistic-regression analysis revealed that only BODE-index (odds ratio 1.40; p = 0.003), lack of companion (2.73; p = 0.045) and younger age (0.93; p = 0.021) were independently associated with depressive symptoms. In a secondary analysis, patients were stratified into those with severe depressive symptoms (GDS ≥ 19) and those with mild depressive symptoms (GDS 11-18). Prevalence of hypogonadism was greater in first group than in the second (62% vs. 26%; p = 0.036). After controlling for confounders, however, gonadal state was not associated with severe depressive symptoms. Similarly, gonadal state was not associated with mood and motivation subscale scores of the GDS. In conclusion, presence of significant depressive symptoms was not associated with hypogonadism in men with COPD.

The genetics of sex differences in brain and behavior

Biological differences between men and women contribute to many sex-specific illnesses and disorders. Historically, it was argued that such differences were largely, if not exclusively, due to gonadal hormone secretions. However, emerging research has shown that some differences are mediated by mechanisms other than the action of these hormone secretions and in particular by products of genes located on the X and Y chromosomes, which we refer to as direct genetic effects. This paper reviews the evidence for direct genetic effects in behavioral and brain sex differences. We highlight the 'four core genotypes' model and sex differences in the midbrain dopaminergic system, specifically focusing on the role of Sry. We also discuss novel research being done on unique populations including people attracted to the same sex and people with a cross-gender identity. As science continues to advance our understanding of biological sex differences, a new field is emerging that is aimed at better addressing the needs of both sexes: gender-based biology and medicine. Ultimately, the study of the biological basis for sex differences will improve healthcare for both men and women.

Depressive symptoms in men aged 50 years and older and their relationship to genetic androgen receptor polymorphism and sex hormone levels in three different samples

OBJECTIVE

Depression in aging men has been related to low sex hormone concentrations; the putatively modulating effects of the genetically determined androgen receptor (AR) cytosine-adenosine-guanine (CAG) repeat polymorphism are often not taken into account. The aim of this study was to determine how sex hormone levels and the AR polymorphism relate to depressive symptoms in aging men.

METHODS

This cross-sectional study of men aged 50 years and older included 120 consecutive patients of the Department of Psychosomatics and Psychotherapy, 76 consecutive patients of the Andrologic Clinic, and 100 participants from the community sample (CS); all participants completed the Patient Health Questionnaire. Morning blood samples were analyzed for total and free testosterone, estradiol, and the AR CAG polymorphism. Patients on hormone substitution or other medication known to influence testosterone levels were excluded.

RESULTS

The two clinical samples had significantly longer AR CAG repeats and higher depression levels compared with the CS. When controlling for possible confounders, depression scores were positively correlated with CAGn (r = 0.20, df: 107, p ≤ 0.038) in psychosomatic patients and with CAGn (r = 0.27, df: 55, p ≤ 0.043) and estradiol (r = 0.31, df: 55, p ≤ 0.019) in andrologic patients, whereas the CS showed no significant correlations between depression scores, CAGn, and sex hormones. CAGn did not correlate significantly with testosterone in the three samples. Regression analysis confirmed association of CAGn with depression.

CONCLUSIONS

Conclusions from these data must be considered to be preliminary and need to be replicated. However, our results point to associations between the genetic AR polymorphism and vulnerability to depressive symptomatology.

Is there a neuroendocrinological rationale for testosterone as a therapeutic option in depression?

Depression is a disease of growing incidence and economic burden worldwide. In view of increasing treatment resistance, new therapeutic approaches are urgently needed. In addition to its gonadal functions, testosterone has many effects on the central nervous system. An association between testosterone levels and depressive symptoms has been proposed. Many hormones and neurotransmitters are involved in the aetiology and the course of depression including serotonin, dopamine, noradrenaline, vasopressin and cortisol. Testosterone is known to interact with them. Preclinical data suggest that testosterone has antidepressant potential. However, the data from clinical studies have been inconsistent. This review provides a critical overview on the currently available preclinical and clinical literature and concludes with clinical recommendations.

Pharmacogenetics of testosterone replacement therapy

Variable phenotypes of androgen insensitivity exist in humans, mainly owing to defective, mutated androgen receptors. A more subtle modulation of androgen effects is related to the CAG repeat polymorphism ([CAG]n) in exon 1 of the androgen receptor gene, in vitro, transcription of androgen-dependent target genes is attenuated with increasing length of triplets. As a clinical entity, the CAG repeat polymorphism can relate to variations of androgenicity in (apparently) eugonadal men in various tissues and psychological traits, the longer the (CAG)n, the less prominent the androgen effect when individuals with similar testosterone concentrations are compared. A strictly defined threshold to hypogonadism is likely to be replaced by a continuum spanned by genetics as well as symptom specificity. In addition, effects of externally applied testosterone can be markedly influenced by the (CAG)n and respective pharmacogenetic implications are likely influence indications as well as modalities of testosterone treatment of hypogonadal men.

Interactions between genotype and depressive symptoms on obesity

Depression and Genetic variation in serotonin and monoamine transmission have both been associated with body mass index (BMI), but their interaction effects are not well understood. We examined the interaction between depressive symptoms and functional polymorphisms of serotonin transporter (SLC6A4) and monoamine oxidase A (MAOA) on categories of BMI. Participants were from the National Longitudinal Study of Adolescent Health. Multiple logistic regression was used to investigate interactions between candidate genes and depression on risk of obesity (BMI > or = 30) or overweight + obese combined (BMI > or = 25). Males with an MAOA active allele with high depressive symptoms were at decreased risk of obesity (OR 0.22; 95% CI 0.06-0.78) and overweight + obesity (OR 0.48; 95% CI 0.26-0.89). No similar effect was observed among females. These findings highlight that the obesity-depression relationship may vary as a function of gender and genetic polymorphism, and suggest the need for further study.

Hypogonadism, decreased sexual desire, and long-term depression in middle-aged men

INTRODUCTION

In middle-aged men, the associations between long-term depressive symptoms and circulating testosterone levels are poorly known, although it is known that testosterone levels decrease with age.

METHODS

A health questionnaire was mailed to a population-based sample from the National Population Register in 1998, 1999, and 2001. Based on their self-reported mental symptoms, a total of 116 men were selected for clinical examination in 2005. Half of them had high and the others low levels of adverse mental symptoms in all three previous follow-ups. A structured clinical interview for Diagnostic and Statistical Manual of Mental Disorders-IV was performed. Depressive symptoms were assessed with the Beck Depression Inventory (BDI) and the Hamilton Depression Rating Scale (HDRS). The Aging Males' Symptoms scale was also compiled and testosterone levels were determined.

RESULTS

In the entire study sample, serum free testosterone levels correlated negatively with both BDI and HDRS scores. In the hypogonadism group (based on free testosterone, 19.8% of the sample), clinically significant depression (BDI score > or = 13) was more than three times as frequent as in the other men (34.8% vs. 10.4%), the odds ratio after multiple adjustments being 4.98 (95% confidence interval 1.66-14.95). A decrease in sexual desire was common in hypogonadism (36%). Nevertheless, it also associated with clinically significant depression, irrespective of free testosterone levels.

DISCUSSION

Long-term and current depressive symptoms, a decreased sexual desire, and low serum free testosterone levels are associated in middle-aged men. Hypogonadism per se and as a cause of decreased sexual desire may be a contributory and possibly treatable factor underlying male depression.

CONCLUSIONS

The findings highlight the need for hormonal status assessment in middle-aged depressive men.

Sex steroid-related candidate genes in psychiatric disorders

Sex steroids readily pass the blood-brain barrier, and receptors for them are abundant in brain areas important for the regulation of emotions, cognition and behaviour. Animal experiments have revealed both important early effects of these hormones on brain development and their ongoing influence on brain morphology and neurotransmission in the adult organism. The important effects of sex steroids on human behaviour are illustrated by, for example, the effect of reduced levels of these hormones on sexual drive and conditions such as premenstrual dysphoric disorder, perimenopausal dysphoria, postpartum depression, postpartum psychosis, dysphoria induced by oral contraceptives or hormonal replacement therapy and anabolic steroid-induced aggression. The fact that men and women (as groups) differ with respect to the prevalence of several psychiatric disorders, certain aspects of cognitive function and certain personality traits may possibly also reflect an influence of sex steroids on human behaviour. The heritability of most behavioural traits, including personality, cognitive abilities and susceptibility to psychiatric illness, is considerable, but as yet, only few genes of definite importance in this context have been identified. Given the important role of sex steroids for brain function, it is unfortunate that relatively few studies so far have addressed the possible influence of sex steroid-related genes on interindividual differences with respect to personality, cognition and susceptibility to psychiatric disorders. To facilitate further research in this area, this review provides information on several such genes and summarizes what is currently known with respect to their possible influence on brain function.