Escitalopram reduces attentional performance in anxious older adults with high-expression genetic variants at serotonin 2A and 1B receptors

Pharmacological approaches to the management of panic disorder in older patients: a systematic review

INTRODUCTION

Recommendations for treating panic disorder (PD) in older patients are scarce. The authors have systematically reviewed whether several recommended medications are superior to others and their optimal doses in this age group.

METHODS

A database search of studies involving patients with PD with/without agoraphobia aged ≥ 60 years was carried out using PubMed, PsycINFO, Embase, and Clinical Trials.gov, from their inception dates to 1 March 2023. Only four (published from 2002 to 2010) of the 1292 records screened were included. A risk of bias assessment was provided. This systematic review was performed using The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA).

RESULTS

Two studies were randomized clinical trials, whereas two were open-label, including paroxetine, citalopram, escitalopram, and sertraline; three studies reported short-term evaluations, whereas one study included a 26-week follow-up. Medications provided benefits, with good tolerability. Preliminary results suggested greater benefits of paroxetine in reducing panic attacks vs. cognitive - behavioral therapy, and an earlier decrease in PAs with escitalopram vs. citalopram. Risk of bias was considerable.

CONCLUSIONS

The pharmacological management of PD in older patients has received no attention. Findings are scant, dated, and affected by methodological flaws; thus, they do not provide significant advances.

The rs6311 of serotonin receptor 2A (5-HT2A) gene is associated with alexithymia and mental health

BACKGROUNDS

Alexithymia, difficulties in identifying and describing one's own feelings, is related to substantial clinical practice. Inspired by the links between serotonin functions and affective disorders, this study investigated associations of the serotonin receptor 2A (5-HT2A) gene with alexithymia and mental health.

METHODS

We differentiated subjects according to two functional polymorphisms (i.e., rs6311 and rs6313) of 5-HT2A gene and scored alexithymia and mental health of college students with the Toronto Alexithymia Scale (TAS-20) and the Symptom Check List-90 (SCL-90), respectively.

RESULTS

The analyses basing on sample 1 (N = 566) and sample 2 (N = 602) indicated that the G allele of rs6311 was related to higher score on the TAS-20 as compared to the AA genotype. The analysis with 467 individuals from sample 2 indicated that the rs6311 was associated with mental health, and this association was mediated by alexithymia.

LIMITATIONS

The potential confounding variables such as depression and anxiety were neglected in the analyses.

CONCLUSIONS

These findings demonstrate the contribution of the 5-HT2A to alexithymia, and highlight the link between alexithymia and mental health at genetic level.

Towards precision medicine in generalized anxiety disorder: Review of genetics and pharmaco(epi)genetics

Generalized anxiety disorder (GAD) is a prevalent and chronic mental disorder that elicits widespread functional impairment. Given the high degree of non-response/partial response among patients with GAD to available pharmacological treatments, there is a strong need for novel approaches that can optimize outcomes, and lead to medications that are safer and more effective. Although investigations have identified interesting targets predicting treatment response through pharmacogenetics (PGx), pharmaco-epigenetics, and neuroimaging methods, these studies are often solitary, not replicated, and carry several limitations. This review provides an overview of the current status of GAD genetics and PGx and presents potential strategies to improve treatment response by combining better phenotyping with PGx and improved analytical methods. These strategies carry the dual benefit of delivering data on biomarkers of treatment response as well as pointing to disease mechanisms through the biology of the markers associated with response. Overall, these efforts can serve to identify clinical, genetic, and epigenetic factors that can be incorporated into a pharmaco(epi)genetic test that may ultimately improve treatment response and reduce the socioeconomic burden of GAD.

Prefrontal cortex executive processes affected by stress in health and disease

Prefrontal cortical executive functions comprise a number of cognitive capabilities necessary for goal directed behavior and adaptation to a changing environment. Executive dysfunction that leads to maladaptive behavior and is a symptom of psychiatric pathology can be instigated or exacerbated by stress. In this review we survey research addressing the impact of stress on executive function, with specific focus on working memory, attention, response inhibition, and cognitive flexibility. We then consider the neurochemical pathways underlying these cognitive capabilities and, where known, how stress alters them. Finally, we review work exploring potential pharmacological and non-pharmacological approaches that can ameliorate deficits in executive function. Both preclinical and clinical literature indicates that chronic stress negatively affects executive function. Although some of the circuitry and neurochemical processes underlying executive function have been characterized, a great deal is still unknown regarding how stress affects these processes. Additional work focusing on this question is needed in order to make progress on developing interventions that ameliorate executive dysfunction.

Genetics of generalized anxiety disorder and related traits

This review serves as a systematic guide to the genetics of generalized anxiety disorder (GAD) and further focuses on anxiety-relevant endophenotypes, such as pathological worry fear of uncertainty, and neuroticism. We inspect clinical genetic evidence for the familialityl heritability of GAD and cross-disorder phenotypes based on family and twin studies. Recent advances of linkage studies, genome-wide association studies, and candidate gene studies (eg, 5-HTT, 5-HT1A, MAOA, BDNF) are outlined. Functional and structural neuroimaging and neurophysiological readouts relating to peripheral stress markers and psychophysiology are further integrated, building a multilevel disease framework. We explore etiologic factors in gene-environment interaction approaches investigating childhood trauma, environmental adversity, and stressful life events in relation to selected candidate genes (5-HTT, NPSR1, COMT, MAOA, CRHR1, RGS2), Additionally, the pharmacogenetics of selective serotonin reuptake inhibitor/serotonin-norepinephrine reuptake inhibitor treatment are summarized (5-HTT, 5-HT2A, COMT, CRHR1). Finally, GAD and trait anxiety research challenges and perspectives in the field of genetics, including epigenetics, are discussed.

Evidence of sexual dimorphism of HTR1B gene on major adult ADHD comorbidities

Attention-deficit/hyperactivity disorder (ADHD) is a very common psychiatric disorder across the life cycle and frequently presents comorbidities. Since ADHD is highly heritable, several studies have focused in the underlying genetic factors involved in its etiology. One of the major challenges in this search is the phenotypic heterogeneity, which could be partly attributable to the sexual dimorphism frequently seen in psychiatric disorders. Taking into account the well-known sexual dimorphic effect observed in serotonergic system characteristics, we differentially tested the influence of HTR1B SNPs (rs11568817, rs130058, rs6296 and rs13212041) on ADHD susceptibility and on its major comorbidities according to sex. The sample comprised 564 adults with ADHD diagnosed according to DSM-IV criteria and 635 controls. There was no association of any HTR1B SNPs tested in relation to ADHD susceptibility. As for the comorbidities evaluated, after correction for multiple tests, significant associations were observed for both rs11568817 and rs130058 with substance use disorders (P_corr = 0.009 and P_corr = 0.018, respectively) and for rs11568817 with nicotine dependence (P_corr = 0.025) in men with ADHD. In women with ADHD, the same rs11568817 was associated with generalized anxiety disorder (P_corr = 0.031). The observed effects of rs11568817 G allele presence conferring risk to either substance use disorders or generalized anxiety disorder according to sex, suggest an overall scenario where a higher transcriptional activity of HTR1B, resulting from the presence of this allele, is related to externalizing behaviors in men and internalizing behaviors in women. These results are consistent with and expand previous evidence of sexual dimorphism of the serotoninergic system.

Bone Turnover with Venlafaxine Treatment in Older Adults with Depression

OBJECTIVES

Epidemiologic data suggest older adults receiving serotonergic antidepressants may have accelerated bone loss. We examined bone turnover marker changes and patient-level variables associated with these changes in older adults receiving protocolized antidepressant treatment.

DESIGN

Open-label, protocolized treatment study.

SETTING

Medical centers in Pittsburgh, St Louis, and Toronto.

PARTICIPANTS

Older adults with major depression (N = 168).

MEASUREMENTS

Serum levels of the bone resorption marker C-terminal cross-linking telopeptide of type 1 collagen (CTX) and the bone formation marker procollagen type 1 N propeptide (P1NP) were assayed before and after 12 weeks of treatment with venlafaxine. Whether CTX and P1NP changes were associated with depression remission and duration of depression and genetic polymorphisms in the serotonin transporter (5HTTLPR) and 1B receptor (HTR1B) were also examined.

RESULTS

CTX increased and P1NP decreased during venlafaxine treatment, a profile consistent with accelerated bone loss. Two individual-level clinical variables were correlated with bone turnover; participants whose depression did not go into remission had higher CTX levels, and those with chronic depression had lower P1NP levels. HTR1B genotype predicted P1NP change, whereas 5HTTLPR genotype was unrelated to either biomarker.

CONCLUSION

Bone turnover markers change with antidepressant treatment in a pattern that suggests accelerated bone loss, although the clinical significance of these changes is unclear. These data are preliminary and argue for a larger, controlled study to confirm whether antidepressants are harmful to bone metabolism and whether certain individuals might be at increased risk.

Epigenetic and genetic variants in the HTR1B gene and clinical improvement in children and adolescents treated with fluoxetine

The serotonin 1B receptor (5-HT_1B) is important to both the pathogenesis of major depressive disorder and the antidepressant effects of selective serotonin reuptake inhibitors. Although fluoxetine has been shown to be effective and safe in children and adolescents, not all patients experience a proper clinical response, which has led to further study into the main factors involved in this inter-individual variability. Our aim was to study the effect of epigenetic and genetic factors that could affect 5-hydroxytryptamine receptor 1B (HTR1B) gene expression, and thereby response to fluoxetine. A total of 83 children and adolescents were clinically assessed 12weeks after of initiating an antidepressant treatment with fluoxetine for the first time. We evaluated the influence of single nucleotide polymorphisms (SNPs) specifically located in transcription factor binding sites (TFBSs) on their clinical improvement. A combined genetic analysis considering the significant SNPs together with the functional variant rs130058 previously associated in our population was also performed. Moreover, we assessed, for the first time in the literature, whether methylation levels of the HTR1B promoter region could be associated with the pharmacological response. Two, rs9361233 and rs9361235, were significantly associated with clinical improvement after treatment with fluoxetine. The heterozygous genotype combination analysis showed a negative correlation with clinical improvement. The lowest improvement was experienced by patients who were heterozygous for all three SNPs. Moreover, a negative correlation was found between clinical improvement and the average methylation level of the HTR1B promoter. These results give new evidence for the role of epigenetic and genetic factors which could modulate HTR1B expression in the pharmacological response to antidepressants.

Genetic Correlates of Spirituality/Religion and Depression: A Study in Offspring and Grandchildren at High and Low Familial Risk for Depression

RATIONALE

Possible genetic correlates of spirituality and depression have been identified in community samples. We investigate some of the previously identified candidates in a sample of families at both high and low-risk for depression.

METHOD

Offspring and grandchildren of individuals at high and low-risk for depression, participating in a multi-wave thirty-year longitudinal study, were assessed for seven SNPS drawn from four single gene candidates associated with systems implicated in both depression and spirituality: Serotonin (5-HT1B and 5-HT2A), Dopamine (DRD2), Oxytocin (OT) and Monoamine Vesicular Transporter (VMAT1).

RESULTS

Dopamine (DRD2) Serotonin (5-HT1B), their Transporter (VMAT1) and Oxytocin (OXTR) were positively associated with a high level of importance of spirituality or religion (S/R) in the group at low familial risk for depression. DRD2 minor allele was associated with both lifetime major depressive disorder (MDD) and spirituality in the low-risk group for depression. No SNPs were related to S/R in the group at high familial risk for depression. OXTR was associated with lifetime MDD in the full sample.

CONCLUSION

Genes for dopamine, serotonin, their vesicular transporter, and oxytocin may be associated with S/R in people at low familial risk for depression. Genes for dopamine may be associated both with S/R and increased risk for depression in people at low-risk for depression, suggesting a common pathway or physiology to mild to moderate depression. MDD is associated with oxytocin across risk groups. In the high-risk group, phenotypic expression of S/R may be suppressed.

IMPLICATIONS

The shared association of DRD2 by S/R and depression, generally found to be inversely related, calls for further research on their common physiological pathways, and the phenotypic expression of these pathways based upon use and environment. Prevention for offspring at high familial risk for depression might include support for the development of child spirituality.

Anxiety is associated with increased risk of dementia in older Swedish twins

INTRODUCTION

We asked whether anxiety is associated with prospective risk of dementia, and the extent to which genetic influences mediate this association.

METHODS

Nondemented twins (n = 1082) from the Swedish Adoption Twin Study of Aging completed an assessment of anxiety symptoms in 1984 and were followed for 28 years.

RESULTS

Baseline anxiety score, independent of depressive symptoms, was significantly associated with incident dementia over follow-up (hazard ratio [HR] = 1.04; 95% confidence interval [CI] = 1.01-1.06). There was 48% increased risk of becoming demented for those who had experienced high anxiety at any time compared with those who had not. In co-twin analyses, the association between anxiety symptoms and dementia was greater for dizygotic (HR = 1.11; 95% CI = 1.02-1.20) compared with monozygotic twins (HR = 1.06; 95% CI = 0.95-1.20), indicating genetic mediation.

DISCUSSION

Anxiety symptoms were associated with increased risk of dementia. Genetic factors common to dementia and anxiety partially mediated this association.

Neurocognitive performance in unmedicated patients with hoarding disorder

OBJECTIVE

Hoarding disorder (HD) is an often incapacitating psychiatric illness associated with a wide range of neurocognitive abnormalities. Some prior neuropsychological studies have found executive dysfunction in HD, but no clear pattern has emerged. One potential reason for discrepant results in previous studies might be the inclusion of patients on psychotropic and other medications that can affect neurocognitive performance. Therefore, we examined neurocognitive functioning in medication-free HD patients. We also added a novel investigation of implicit learning, which has been found to be abnormal in obsessive-compulsive disorder (OCD) and related disorders.

METHOD

Twenty-six participants meeting the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association, 2013) diagnostic criteria for HD and 23 normal controls were administered a battery of neuropsychological tests and symptom rating scales. All participants were free of psychotropic medications for at least 6 weeks prior to the study.

RESULTS

HD participants showed no significant differences from normal controls on measures of verbal memory, attention, or executive functioning, including response inhibition, planning, organization, and decision making. However, HD participants demonstrated a trend toward less implicit learning and greater use of explicit learning strategies during perceptual categorization compared to normal controls. HD participants who used an implicit strategy performed significantly worse than controls who used an implicit strategy. Hoarding symptom severity was not associated with neurocognitive performance.

CONCLUSIONS

HD patients may have a tendency to use explicit rather than implicit learning strategies for perceptual categorization but perform as well as normal controls on many other neurocognitive measures. Future studies should assess unmedicated participants and examine test strategies, not just outcomes.

Common selective serotonin reuptake inhibitor side effects in older adults associated with genetic polymorphisms in the serotonin transporter and receptors: data from a randomized controlled trial

OBJECTIVE

Antidepressant side effects are a significant public health issue, associated with poor adherence, premature treatment discontinuation, and, rarely, significant harm. Older adults assume the largest and most serious burden of medication side effects. We investigated the association between antidepressant side effects and genetic variation in the serotonin system in anxious, older adults participating in a randomized, placebo-controlled trial of the selective serotonin reuptake inhibitor (SSRI) escitalopram.

METHODS

Adults (N = 177) aged ≥ 60 years were randomized to active treatment or placebo for 12 weeks. Side effects were assessed using the Udvalg fur Kliniske Undersøgelser side-effect rating scale. Genetic polymorphisms were putative functional variants in the promoters of the serotonin transporter and 1A and 2A receptors (5-HTTLPR [L/S + rs25531], HTR1A rs6295, HTR2A rs6311, respectively).

RESULTS

Four significant drug-placebo side-effect differences were found: increased duration of sleep, dry mouth, diarrhea, and diminished sexual desire. Analyses using putative high- versus low-transcription genotype groupings revealed six pharmacogenetic effects: greater dry mouth and decreased sexual desire for the low- and high-expressing serotonin transporter genotypes, respectively, and greater diarrhea with the 1A receptor low-transcription genotype. Diminished sexual desire was experienced significantly more by high-expressing genotypes in the serotonin transporter, 1A, or 2A receptors. There was not a significant relationship between drug concentration and side effects nor a mean difference in drug concentration between low- and high-expressing genotypes.

CONCLUSION

Genetic variation in the serotonin system may predict who develops common SSRI side effects and why. More work is needed to further characterize this genetic modulation and to translate research findings into strategies useful for more personalized patient care.

Genetic variation in the serotonin transporter and HTR1B receptor predicts reduced bone formation during serotonin reuptake inhibitor treatment in older adults

OBJECTIVES

Studies have reported an association between serotonin reuptake inhibitors (SRIs) and accelerated bone loss. Genetic variation in the serotonin system might modulate bone metabolism changes during SRI treatment. In a clinical trial we examined functional genetic polymorphisms of serotonin transporter and receptors involved in bone metabolism to determine whether they predict changes in bone metabolism during SRI treatment.

METHODS

In 69 adults (age ≥ 60) participating in a 12-week, open-label trial of the SRI venlafaxine for major depression, serum markers of bone formation (P1NP) and resorption (β-CTX) were assayed before and after treatment. Participants were genotyped for putative high- versus low-expressing polymorphisms in the serotonin transporter (5HTTLPR) and 1B receptor (HTR1B) genes.

RESULTS

Bone formation was significantly reduced with administration of venlafaxine in participants with the high-expressing 5HTTLPR genotype and those with the low-expressing HTR1B genotype. This primarily occurred in individuals with the combination of the high-expressing 5HTTLPR genotype and the low-expressing HTR1B genotype.

CONCLUSIONS

These preliminary findings indicate that genetic variation in the serotonin receptors predicts changes in bone metabolism during SRI use. If these results are replicated and clinically confirmed, we will have identified a genetic subgroup at high risk for deleterious bone outcomes with the use of SRIs.

Understanding the pharmacogenetics of selective serotonin reuptake inhibitors

INTRODUCTION

The genetic background of antidepressant response represents a unique opportunity to identify biological markers of treatment outcome. Encouraging results alternating with inconsistent findings made antidepressant pharmacogenetics a stimulating but often discouraging field that requires careful discussion about cumulative evidence and methodological issues.

AREAS COVERED

The present review discusses both known and less replicated genes that have been implicated in selective serotonin reuptake inhibitors (SSRIs) efficacy and side effects. Candidate genes studies and genome-wide association studies (GWAS) were collected through MEDLINE database search (articles published till January 2014). Further, GWAS signals localized in promising genetic regions according to candidate gene studies are reported in order to assess the general comparability of results obtained through these two types of pharmacogenetic studies. Finally, a pathway enrichment approach is applied to the top genes (those harboring SNPs with p < 0.0001) outlined by previous GWAS in order to identify possible molecular mechanisms involved in SSRI effect.

EXPERT OPINION

In order to improve the understanding of SSRI pharmacogenetics, the present review discusses the proposal of moving from the analysis of individual polymorphisms to genes and molecular pathways, and from the separation across different methodological approaches to their combination. Efforts in this direction are justified by the recent evidence of a favorable cost-utility of gene-guided antidepressant treatment.