Serotonin transporter gene influences the time course of improvement of "core" depressive and somatic anxiety symptoms during treatment with SSRIs for recurrent mood disorders

The Impact of Development on Antidepressant and Placebo Response in Anxiety Disorders: A Bayesian Hierarchical Meta-Analytic Examination of Randomized Controlled Trials in Children, Adolescents, and Adults

Background: Understanding how development influences medication and placebo responses in anxiety disorders could inform treatment decisions, including age-specific first- versus second-line psychopharmacological interventions. Objective: To meta-analytically compare the trajectory of selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and placebo response in youth and adults with anxiety disorders. Methods: Weekly symptom severity data were extracted from prospective, randomized, parallel-group, placebo-controlled trials of SSRIs and SNRIs in children, adolescents, and adults with anxiety disorders (generalized, separation, and social anxiety disorders as well as panic disorder). Treatment response was modeled for the standardized change in continuous measures of anxiety using a Bayesian hierarchical model. Change in symptom severity was evaluated as a function of time, and post hoc analyses were conducted to determine the sensitivity of these results across sample heterogeneity and alternative functional forms. Results: Data were included from 11 trials of youth (SSRI, κ = 7; SNRI, κ = 4) and 71 studies of adults (SSRI, κ = 46; SNRI, κ = 25). In total, 1067 youth participated in SSRI trials and 1024 in SNRI trials. In total, 10,826 adults participated in SSRI trials (placebo, n = 5367; SSRI n = 5,459) and 6232 in SNRI trials (placebo, n = 3,128; SNRI n = 3,094). A logarithmic model best described the response. Placebo response was similar in youth and adults (mean difference = -1.98 ± 6.21, 95% credible interval [CrI]: -10.2 to 14.2, p = 0.750), and statistically significant improvement from baseline emerged by week 2 in both adults (mean difference: -18.34 + 1.017, 95% CrI: -20.3 to 16.3, p < 0.001) and youth (mean difference: -23.74 + 3.736, 95% CrI: -31.1 to -16.4, p < 0.001). SSRIs produced similar improvements for youth and adults (p = 0.129), but SNRIs produced slower improvement in youth than adults (p = 0.018). Conclusions: Antidepressant-related improvement occurs early in youth and adults with anxiety disorders. SSRI response is similar in adults and youth; however, SNRIs produce greater responses in adults than youth, potentially representing a developmental effect.

Understanding the Biological Relationship between Migraine and Depression

Migraine is a highly prevalent neurological disorder. Among the risk factors identified, psychiatric comorbidities, such as depression, seem to play an important role in its onset and clinical course. Patients with migraine are 2.5 times more likely to develop a depressive disorder; this risk becomes even higher in patients suffering from chronic migraine or migraine with aura. This relationship is bidirectional, since depression also predicts an earlier/worse onset of migraine, increasing the risk of migraine chronicity and, consequently, requiring a higher healthcare expenditure compared to migraine alone. All these data suggest that migraine and depression may share overlapping biological mechanisms. Herein, this review explores this topic in further detail: firstly, by introducing the common epidemiological and risk factors for this comorbidity; secondly, by focusing on providing the cumulative evidence of common biological aspects, with a particular emphasis on the serotoninergic system, neuropeptides such as calcitonin-gene-related peptide (CGRP), pituitary adenylate cyclase-activating polypeptide (PACAP), substance P, neuropeptide Y and orexins, sexual hormones, and the immune system; lastly, by remarking on the future challenges required to elucidate the etiopathological mechanisms of migraine and depression and providing updated information regarding new key targets for the pharmacological treatment of these clinical entities.

Serotonin Transporter Genetic Variation and Antidepressant Response and Tolerability: A Systematic Review and Meta-Analysis

Antidepressants are used to treat several psychiatric disorders; however, a large proportion of patients do not respond to their first antidepressant therapy and often experience adverse drug reactions (ADR). A common insertion–deletion polymorphism in the promoter region (5-HTTLPR) of the serotonin transporter (SLC6A4) gene has been frequently investigated for its association with antidepressant outcomes. Here, we performed a systematic review and meta-analysis to assess 5-HTTLPR associations with antidepressants: (1) response in psychiatric disorders other than major depressive disorder (MDD) and (2) tolerability across all psychiatric disorders. Literature searches were performed up to January 2021, yielding 82 studies that met inclusion criteria, and 16 of these studies were included in the meta-analyses. Carriers of the 5-HTTLPR LL or LS genotypes were more likely to respond to antidepressant therapy, compared to the SS carriers in the total and European ancestry-only study populations. Long (L) allele carriers taking selective serotonin reuptake inhibitors (SSRIs) reported fewer ADRs relative to short/short (SS) carriers. European L carriers taking SSRIs had lower ADR rates than S carriers. These results suggest the 5-HTTLPR polymorphism may serve as a marker for antidepressant outcomes in psychiatric disorders and may be particularly relevant to SSRI treatment among individuals of European descent.

Omega-3 polyunsaturated fatty acids in cardiovascular diseases comorbid major depressive disorder - Results from a randomized controlled trial

INTRODUCTION

Cardiovascular diseases (CVDs) and major depressive disorder (MDD) will be the two most disabling diseases by 2030. Patients with CVDs comorbid depression had lower levels of total omega-3 polyunsaturated fatty acids (n-3 PUFAs), docosahexaenoic acid (DHA), and a higher omega-6 to omega-3 ratio. However, there have been limited studies on the effects n-3 PUFAs on MDD in patients with CVDs.

METHOD

We have enrolled a total of 59 patients (64% males, mean age of 61.5 ± 9.0 years and mean education of 10.2 ± 4.2 years) with CVDs comorbid MDD. They were randomized into either receiving n-3 PUFAs (2 g per day of eicosapentaenoic acid (EPA) and 1 g of DHA) or placebo for 12 weeks. We assessed depression symptom severity with Hamilton Depression Rating Scale (HAMD) and Beck Depression Inventory (BDI), as well as blood fatty acid levels, electrocardiogram and blood biochemistry, at the baseline and at the endpoint.

RESULTS

There were no differences between the n-3 PUFAs and placebo group in the changes of HAMD and BDI total scores, while PUFAs group had a greater reduction in HAMD Cognition subscale scores than the placebo group at week 8 (p < 0.05). Moreover, subgroup analyses found that the n-3 group had a greater reduction of HAMD Core subscale scores than the placebo group at the end of week 12 (p < 0.05) for the very severe DEP group (HAMD ≥ 23).

CONCLUSION

Overall, n-3 PUFAs did not show a beneficial effect on depressive symptoms when compared with placebo. However, when stratified with depression severity, n-3 PUFAs supplementation improved core depression symptoms in the very severe MDD group. N-3 PUFAs supplementation may provide a treatment option for a subpopulation of patients with CVDs comorbid MDD.

Plasma levels of IL-6 in patients with untreated major depressive disorder: comparison with catecholamine metabolites

OBJECTIVE

IL-6 and catecholamines play roles in the pathophysiology of major depressive disorder (MDD).

AIM

The present study investigated associations between plasma IL-6 and plasma catecholamine metabolites in patients with MDD.

PARTICIPANTS AND METHODS

A total of 148 patients (male/female 65/83, age 49.5±12.1 years) who met the criteria for MDD based on the Diagnostic and Statistical Manual of Mental Disorders IV and 40 participants as healthy controls (HC; male/female 23/17, age 44.0±10.5 years) were enrolled in the present study. Plasma levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) and homovanillic acid (HVA) were analyzed using high-performance liquid chromatography, and plasma IL-6 levels were measured using ELISA.

RESULTS

No correlations were observed among plasma IL-6 levels, MHPG levels, and HVA levels in patients with MDD. Plasma IL-6 levels in patients with MDD were significantly higher than in the HC. A positive correlation was found between plasma IL-6 levels and Hamilton Rating Scale for Depression-17 scores.

CONCLUSION

No correlations existed between plasma IL-6 levels and plasma catecholamine metabolite levels in patients with MDD, and the severity of depressive state was related to plasma IL-6 levels in MDD.

Interferon-alpha-induced depression: Comparisons between early- and late-onset subgroups and with patients with major depressive disorder

Interferon (IFN)-alpha, until recently the standard treatment of hepatitis C virus (HCV) infection, is associated with a significant risk of major depressive episode (MDE, or IFN-alpha-induced depression). However, it is little studied the comparisons of clinical manifestations between IFN-alpha-induced depression and major depressive disorder (MDD). In addition, IFN-alpha induces different neuroinflammation and neuroendocrine status throughput the HCV treatment course; however, the clinical presentations have never been compared between early-onset and later-onset IFN-alpha-induced depression. We assessed 200 HCV patients starting IFN-alpha therapy bi-weekly for 24 weeks, with the structured interview for confirmation of diagnosis of IFN-alpha-induced depression and with clinical rating scales for depressive symptoms and neuropsychiatric symptoms. Subjects developed IFN-alpha-induced depression (n = 59, 30%) during the first 6 weeks of IFN-alpha therapy were defined as the early-onset group (n = 32), while those developed depression after the 6th week were defined as the late-onset group (n = 27). A matched group of MDD patients (n = 60) was used to compare specific clusters of depressive symptoms with early- and late-onset IFN-alpha-induced depression. Compared to the matched group of MDD patients, IFN-alpha-induced depression was significantly associated with more somatic symptoms and fewer symptoms of mood, anxiety and negative cognition. More somatic symptoms were also found in those who became clinically depressed at early stage of IFN-alpha therapy. We suggest that the specific somatic features of interferon-alpha-induced depression, and especially of early-onset depression, characterise individuals who are more sensitive to cytokines-induced changes in mood.

BanI polymorphism of cytosolic phospholipase A2 gene and somatic symptoms in medication-free acute depressed patients

Somatic symptoms are commonly seen in patients with major depressive disorder (MDD) and might be associated with inflammatory activation. Cytosolic phospholipase A2 (cPLA2) and cyclo-oxygenase-2 (COX-2) are the key enzymes in the metabolism of polyunsaturated fatty acids (PUFAs), which in turn may play an important role in inflammation and somatic symptoms in depression. This study investigated the effects of BanI polymorphism of cPLA2 gene and COX-2 rs4648308 genotypes on somatic symptoms and inflammatory marker in patients with MDD. Eighty-two patients with MDD were assessed for their psychopathology including psychiatric and somatic symptoms, BanI polymorphism of cPLA2 and COX-2 rs4648308 genotypes and CRP levels. The results revealed that MDD patients with the cPLA2 BanI GG genotypes had higher somatic symptoms and higher levels of C-reactive protein (CRP), while no differences were found among the COX-2 rs4648308 genotypes. Inflammatory process, such as arachidonic acid cascade pathway, might help explain the effect of cPLA2 BanI polymorphism on the somatic symptoms, and may be a potential target for future investigation on treatment for MDD with somatic symptoms. However, the interpretation of the findings in this study is limited since we analyzed the data from a subset data from a larger study.

5-HTTLPR Polymorphism of Serotonin Transporter and Effects of Sertraline in Terminally Ill Cancer Patients: Report of Eleven Cases

Depression is difficult to detect in cancer patients, though its determination offers an opportunity to relieve patients’ suffering in palliative care. Selective serotonin reuptake inhibitors (SSRIs) are the treatment of choice for mood disorders, but they show a highly variable response. The short allelic variants “s/s” and “s/l” of the 5-HTTLPR polymorphism in the promoter region of the serotonin transporter gene has been consistently associated with a poorer response to SSRIs. The aim of this study has therefore been to examine depression, anxiety and mental adaptation to cancer in terminally ill and depressed cancer patients, in relation to treatment with sertraline and to the 5-HTTLPR genetic polymorphism. Eleven consecutive depressed patients with different forms of advanced cancer who were admitted to the Hospice of the Casa di Cura “Pineta del Carso” (Trieste, Italy) were treated with sertraline for two weeks and their response was determined and related to 5-HTTLPR.

Sertraline significantly reduced the average depression and anxiety subscale scores of HADS, as well as the scores of the subscales of Mini-MAC. When the effects of sertraline were analyzed in relation to the 5-HTTLPR polymorphism, only patients with the “l/l” allelic variant had significantly lower scores of HADS anxiety, Mini-MAC hopelessness-helplessness and anxious preoccupation, and a higher score for the fighting spirit of Mini-MAC; the depression score was significantly reduced in patients with both allelic variants. These data indicate that sertraline is effective after two weeks of treatment in terminally ill cancer patients, acting not only on depression but also on anxiety and mental adaptation to cancer. Moreover, the effect of sertraline significantly depended on the genetic polymorphism of the serotonin transporter, being more pronounced in patients carrying the “l/l” genetic variant; these findings seem to encourage the examination of a larger sample of patients.

Pharmacogenetics of escitalopram and mental adaptation to cancer in palliative care: Report of 18 cases

Aims and background

In palliative care, few data are available on the diagnosis and treatment of mood disorders and of difficulties of mental adaptation to cancer for patients in the advanced phases of the disease. SSRI antidepressants are the treatment of choice; the 5-HTTLPR genetic polymorphism of the serotonin transporter (SERT) has been shown in psychiatry to significantly determine the therapeutic response and the incidence of adverse effects. The aim of the present investigation has been therefore to examine the effects of the SSRI antidepressant escitalopram, also considering 5-HTTLPR, on depression, anxiety and mental adaptation to cancer in palliative care.

Methods and study design

Eighteen consecutive depressed patients with different forms of advanced cancer admitted to the Hospice Ass 6 of S. Vito al Tagliamento (Pordenone, Italy) were genotyped for the “s” and “l” variants of 5-HTTLPR and were treated with escitalopram. Their response after two weeks of treatment was psycho-metrically evaluated.

Results

Treatment with escitalopram significantly decreased anxiety scores on the Hospital Anxiety and Depression Scale (HADS) (P = 0.006) as well as anxious preoccupation (P = 0.007) and hopelessness-helplessness (P = 0.017) scores on the Mini Mental Adjustment to Cancer (Mini-MAC) scale. When patients were stratified by SERT genotype, HADS anxiety was significantly decreased in patients carrying the “s/s” and “s/l” variants (P = 0.024), whereas those with an “l/l” genotype displayed a significant reduction of Mini-MAC anxious preoccupation (P = 0.018).

Conclusions

The results of this study indicate that the use of SSRI antidepressants is effective in the palliative care of cancer patients, and their action affects not only depression but also the patients' mental adaptation to the disease. These results encourage further examination of these drugs in a larger cohort of patients. The significant contribution of pharmacogenetics indicates the possibility of personalized treatment with SSRIs in palliative care.

Serotonin Transporter 5-HTTLPR Polymorphism and Response to Citalopram in Terminally ill Cancer Patients: Report of Twenty-One Cases

The aim of this study was to examine the effects of the SSRI antidepressant drug citalopram on anxiety, depression and mental adjustment to cancer in terminally ill cancer patients, considering also the 5-HTTLPR genetic polymorphism.

A group of twenty-one consecutive patients admitted to the hospice of the Casa di Cura Pineta del Carso (Trieste, Italy) with different types of advanced cancer, who were clinically judged to require treatment with an antidepressive drug, was treated with citalopram for two weeks. The response was determined and related to 5-HTTLPR.

Citalopram significantly reduced the scores on the depression and anxiety subscales of the Hospital Anxiety and Depression Scale (HADS). When the effects of citalopram were analyzed in relation to the 5-HTTLPR polymorphism, the HADS depression score was significantly decreased only in patients with the “l/l” allelic variant of the serotonin transporter conferring high functional activity, while the score of the Mini-MAC fatalism scale was significantly increased in patients carrying at least one “s” allele. These preliminary findings seem to indicate that two weeks of treatment with citalopram are effective in reducing depressive symptoms in terminally ill cancer patients. Moreover, the effects of citalopram on fatalism as a strategy of mental adaptation to cancer, and on depressive symptoms depend on the allelic variants of the 5-HTTLPR genotype of the patients. These results seem to encourage the examination of a larger patient sample and of different treatment schedules, as well as a more thorough characterization of fatalism as a coping strategy in cancer patients.

Bifidobacterium and Lactobacillus Counts in the Gut Microbiota of Patients With Bipolar Disorder and Healthy Controls

Background: Although the pathophysiology of bipolar disorder remains elusive, growing evidence suggests the beneficial effects of Bifidobacterium and Lactobacillus in the gut microbiota on stress response and depressive symptoms. In the present study, we examined Bifidobacterium and Lactobacillus counts for association with bipolar disorder and serum cortisol levels. Methods: Bacterial counts in fecal samples were examined in 39 patients with bipolar disorder according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edn. and 58 healthy controls using bacterial rRNA-targeted reverse transcription-quantitative polymerase chain reaction. Results: No significant difference was found in either bacterial counts between the two groups. However, we found a significantly negative correlation between Lactobacillus counts and sleep (ρ = -0.45, P = 0.01). Furthermore, a significant negative correlation was found between Bifidobacterium counts and cortisol levels (ρ = -0.39, P = 0.02) in the patients, although such a correlation was not found for Lactobacillus counts. Conclusions: Our results suggest that Bifidobacterium or Lactobacillus counts may not play a major role in the pathophysiology of bipolar disorder in our sample. However, the observed negative correlation between Lactobacillus counts and sleep and that between Bifidobacterium counts and serum cortisol levels point to the possible roles of these bacteria in sleep and stress response of the patients.

Paroxetine versus Venlafaxine and Escitalopram in Korean Patients with Major Depressive Disorder: A Randomized, Rater-blinded, Six-week Study

Objective

The purpose of this study was to compare the efficacy and safety of escitalopram, paroxetine and venlafaxine in Korean patients with major depressive disorder (MDD).

Methods

A total of 449 Korean MDD patients were recruited in a six-week, randomized, rater-blinded, active-controlled trial and were evenly randomized to paroxetine, venlafaxine, or escitalopram treatment.

Results

When comparing the mean difference for the Montgomery-Åsberg Depression Rating Scale (MADRS) and the Hamilton Depression Rating Scale (HDRS) total scores during six weeks, paroxetine (−6.4±0.4, and −5.4±0.4, respectively) was found to be significantly superior to escitalopram (−3.7±0.5 and −3.1±0.4, respectively). Venlafaxine had a significantly lower MADRS total score (−5.4±0.4) than escitalopram. When adjusting baseline variables, the response, according to the MADRS and HDRS scores, in the paroxetine group was greater than that for the escitalopram group (odds ratio [OR]=2.43, 95% confidence interval [CI]=1.42–4.16 for MADRS; and OR=2.32, 95% CI=1.35–3.97 for HDRS) and the venlafaxine group (OR=1.94, 95% CI=1.17–3.21 for MADRS; and OR=1.71, 95% CI=1.03–2.83 for HDRS). Despite that the overall tolerability was high and similar among the three groups, a total of 268 subjects (59.7%) prematurely discontinued treatment, representing the main limitation of the present study.

Conclusion

Although a low study completion rate limits generalizability, our findings suggest that paroxetine might be superior to escitalopram in Korean MDD patients. Further studies should be conducted to draw a definite conclusion.

Distinctive Clinical Correlates of Psychotic Major Depression: The CRESCEND Study

OBJECTIVE

The purpose of this investigation was to identify distinctive clinical correlates of psychotic major depression (PMD) as compared with non-psychotic major depression (NPMD) in a large cohort of Korean patients with major depressive disorder (MDD).

METHODS

We recruited 966 MDD patients of age over 18 years from the Clinical Research Center for Depression of South Korea (CRESCEND) study. Diagnoses of PMD (n=24) and NPMD (n=942) were made with the DSM-IV definitions and confirmed with SCID. Psychometric scales were used to assess overall psychiatric symptoms (BPRS), depression (HAMD), anxiety (HAMA), global severity (CGI-S), suicidal ideation (SSI-Beck), functioning (SOFAS), and quality of life (WHOQOL-BREF). Using independent t-tests and χ(2) tests, we compared clinical characteristics of patients with PMD and NPMD. A binary logistic regression model was constructed to identify factors independently associated with increased likelihood of PMD.

RESULTS

PMD subjects were characterized by a higher rate of inpatient enrollment, and higher scores on many items on BPRS (somatic concern, anxiety, emotional withdrawal, guilt feelings, tension, depression, suspiciousness, hallucination, motor retardation, blunted affect and excitement) global severity (CGI-s), and suicidal ideation (SSI-Beck). The explanatory factor model revealed that high levels of tension, excitement, and suicidal ideation were associated with increased likelihood of PMD.

CONCLUSION

Our findings partly support the view that PMD has its own distinctive clinical manifestation and course, and may be considered a diagnostic entity separate from NPMD.

Serotonin transporter polymorphism is associated with increased apnea-hypopnea index in older adults

RATIONALE

A functional polymorphism of the serotonin transporter gene (5-HTTLPR) has previously been related to upper airway pathology, but its contribution to obstructive sleep apnea (OSA), a highly prevalent sleep disorder in older adults, remains unclear.

OBJECTIVES

We aimed to investigate the relationship between apnea-hypopnea index (AHI) and genetic variations in the promoter region of the 5-HTTLPR in older adults.

METHODS

DNA samples from 94 community-dwelling older adults (57% female, mean age 72 ± 8) were genotyped for the 5-HTTLPR polymorphism. All participants were assessed in their homes with full ambulatory polysomnography in order to determine AHI and related parameters such as hypoxia, sleep fragmentation, and self-reported daytime sleepiness.

RESULTS

The 5-HTT l allele was significantly associated with AHI (p = 0.019), with l allele carriers displaying a higher AHI than s allele homozygotes. A single allele change in 5-HTTLPR genotype from s to l resulted in an increase of AHI by 4.46 per hour of sleep (95% CI, 0.75-8.17). The l allele was also associated with increased time during sleep spent at oxygen saturation levels below 90% (p = 0.014).

CONCLUSIONS

The observed significant association between the 5-HTTLPR l allele and severity of OSA in older adults suggests that the l allele may be important to consider when assessing for OSA in this age group. This association may also explain some of the observed variability among serotonergic pharmacological treatment studies for OSA, and 5-HTT genotype status may have to be taken into account in future therapeutic trials involving serotonergic agents.

The effects of Psychotropic drugs On Developing brain (ePOD) study: methods and design

BACKGROUND

Animal studies have shown that methylphenidate (MPH) and fluoxetine (FLX) have different effects on dopaminergic and serotonergic system in the developing brain compared to the developed brain. The effects of Psychotropic drugs On the Developing brain (ePOD) study is a combination of different approaches to determine whether there are related findings in humans.

METHODS/DESIGN

Animal studies were carried out to investigate age-related effects of psychotropic drugs and to validate new neuroimaging techniques. In addition, we set up two double-blind placebo controlled clinical trials with MPH in 50 boys (10-12 years) and 50 young men (23-40 years) suffering from ADHD (ePOD-MPH) and with FLX in 40 girls (12-14 years) and 40 young women (23-40 years) suffering from depression and anxiety disorders (ePOD-SSRI). Trial registration numbers are: Nederlands Trial Register NTR3103 and NTR2111. A cross-sectional cohort study on age-related effects of these psychotropic medications in patients who have been treated previously with MPH or FLX (ePOD-Pharmo) is also ongoing. The effects of psychotropic drugs on the developing brain are studied using neuroimaging techniques together with neuropsychological and psychiatric assessments of cognition, behavior and emotion. All assessments take place before, during (only in case of MPH) and after chronic treatment.

DISCUSSION

The combined results of these approaches will provide new insight into the modulating effect of MPH and FLX on brain development.

Systematic review and meta-analysis of serotonin transporter genotype and discontinuation from antidepressant treatment

There is evidence that 5-HTTLPR is associated with response following treatment from selective serotonin reuptake inhibitors (SSRIs). The short (S) allele has reduced serotonin transporter expression, compared to the long (L) allele, and has been reported to be associated with poorer response in Europeans, with the effect in other populations unclear. However the published literature is inconsistent. A systematic review and meta-analysis was performed to investigate the effect of 5-HTTLPR on discontinuation from antidepressant treatment. Data were obtained from 17 studies including 4309 participants. The principal outcome measure was the allelic odds ratio (OR) for the 5-HTTLPR S allele and discontinuation status. A random effects meta-analysis provided no evidence that the S allele was associated with increased odds of discontinuation from SSRIs in Europeans (OR 1.09, 95% CI 0.83-1.42, p=0.53; 10 studies, n=2504) but in East Asians there was evidence of a reduced odds of discontinuation (OR 0.28, 95% CI 0.12-0.64, p=0.002; 2 studies, n=136). There was a suggestion of small study bias (p=0.05). This meta-analysis provides no evidence of an association between 5-HTTLPR and discontinuation from antidepressant treatment in Europeans. The low number of studies in East Asian samples using SSRIs reduces confidence in our evidence that the S allele decreases the odds of discontinuation in this population. At present, there is no evidence of an association between 5-HTTLPR and discontinuation from SSRI treatment in a European population with further studies required to investigate its effects in different populations.

Somatization in major depression--clinical features and genetic associations

OBJECTIVE

To identify clinical variables and genetic variations within monoaminergic genes known to be implicated in pain perception that are associated with the occurrence of somatization symptoms in patients with major depression.

METHOD

Somatization was evaluated using the respective subscale of the Symptom Checklist SCL-90-R. Six monoaminergic genes were identified showing an involvement in pain perception and somatization according to the literature: COMT, HTR2A, SLC6A2, SLC6A4, DRD4, and TPH1. One hundred and eighteen single nucleotide polymorphisms (SNPs) within these genes were genotyped using Illumina BeadChips in a sample of 398 at least moderately to severely depressed in-patients participating in the Munich Antidepressant Response Signature (MARS) project.

RESULTS

Thirty SNPs exhibit nominally significant associations with somatization. One SNP (rs9534505) located in intron 2 of the HTR2A gene withstood correction for multiple testing. Clinical data provide further evidence for strong impact of somatization on the presentation of depressive symptoms and description of a patient subgroup with unfavorable clinical outcome.

CONCLUSION

Our results demonstrate the influence of a HTR2A polymorphism on aspects of somatization in major depression, which co-occurs with an unfavorable antidepressant treatment outcome. These results confirm and expand previous findings on somatization as a risk factor for treatment outcome in major depression.

Incomplete coverage of candidate genes: a poorly considered bias

Current genetic investigations are performed both on the basis of a rational and biologically based choice of candidate genes and through genome wide scans. Nonetheless, lack of replication is a common problem in psychiatric genetics as well as in other genetic fields. There are a number of reasons for this inconsistency, among them a well known but poorly considered issue is gene coverage. The aim of the present paper is to focus on this well known and defectively deemed bias, especially when a candidate gene approach is chosen. The rational and the technical feasibility of this proposal are discussed as well as a survey of current investigations. The known consistent methodology to fix this bias is also discussed.

Variation in GNB3 predicts response and adverse reactions to antidepressants

There is substantial inter-individual variation in response and adverse reactions to antidepressants, and genetic variation may, in part, explain these differences. GNB3 encodes the β3 subunit of the G protein complex, which is involved in the downstream signalling cascade following monoamine receptor activation. A functional polymorphism in this gene (C825T) has been associated with response to antidepressants. Several lines of evidence suggest that GNB3 moderates improvement in the neurovegetative symptoms of depression (such as sleep and appetite) and related adverse reactions independently of change in core mood symptoms. We here report analysis of data from GENDEP, a part-randomized pharmacogenomic trial, on the outcome of 811 subjects with major depression undergoing treatment with either escitalopram or nortriptyline in which the C825T SNP and three further SNPs in GNB3 were genotyped. The TT genotype was significantly associated with a superior response to nortriptyline and these effects were specific to improvements in neurovegetative symptoms. In addition, the same genotype predicted fewer incidents of treatment-emergent insomnia and greater weight gain on the same drug. Our results are consistent with previous associations with GNB3 and emphasize the importance of signalling genes in antidepressant response.

Pharmacogenomic testing and outcome among depressed patients in a tertiary care outpatient psychiatric consultation practice

The authors tested the hypothesis that pharmacogenomic genotype knowledge is associated with better clinical and cost outcomes in depressed patients, after controlling for other factors that might differentiate tested and non-tested patients. Medical records of 251 patients, seen in the Mayo Clinic Rochester outpatient psychiatric practice, who had patient health questionnaire-9 (PHQ-9) scores before and after consultation, were reviewed. Comparisons of differences in pre-consultation and post-consultation depression scores and slopes between tested and non-tested patients and between genotype categories of tested patients, were evaluated, along with healthcare cost and utilization comparisons between tested and non-tested patients, using Kruskal-Wallis tests, Wilcoxon rank-sum tests and group mean comparisons, controlling for significant univariate demographic and clinical differences. Tested patients had significantly higher depression diagnosis frequency, baseline PHQ-9 scores, family history of depression, psychiatric hospitalization history, and higher numbers of antidepressant, mood stabilizer and antipsychotic medication trials. After controlling for these differences, there were no differences between tested and non-tested patients in post-baseline depression scores or slopes for CYP genotype categories. For patients with 5-HTTLPR testing, there was significantly more depression score improvement for patients with the long/long genotype at time 4 (N=55, χ(2)-value=8.0492, P=0.018) and at time 5 (N=44, χ(2)-value=6.1492, P=0.046). For a subgroup (n=46) with ≥two pre- and ≥two post-baseline PHQ-9 scores, the mean difference between pre-baseline and post-baseline PHQ-9 score slopes for tested patients was -0.08 (median -0.01; range -1.20 to 0.15) compared with 0.13 (median 0.02; range -0.18 to 2.16) for non-tested patients (P=0.03). Among genotype categories, mean differences between pre-consultation and post-consultation slopes were significantly better for poor CYP2D6 metabolizers than intermediate or extensive metabolizers (P=0.04); there was a trend for slope differences to be better for 5-HTTLPR long/long genotype patients (P=0.06). Subsets of local tested and consultant-adjusted non-tested controls (n=19), who had 8 years of longitudinal care within the health system, had similar overall mean healthcare costs before and after testing; however, tested patients on average had significantly fewer time-adjusted post-baseline psychiatric admissions (0.8 vs 3.8, P=0.04) and fewer time-adjusted psychiatric consultations and comprehensive mental health-specialty evaluations (4.2 vs 9.9, P=0.03). Prospective study is indicated as to whether and how pharmacogenomic testing in a psychiatric consultation practice may improve clinical and cost outcomes.

Pharmacogenetics of antidepressive treatment

The search of the genetic predictors of response to antidepressants is a rapidly expanding field. A large number of clinical studies are reporting partly inconsistent results. Emerging new results focus on new candidate single nucleotide polymorphisms--particularly in the 5HT2a-receptor gene and the gene coding for the co-chaperone FKBP5. The impact of the 5HTTLPR polymorphism on therapeutic outcome and side effects under treatment with SSRIs has to be viewed in a more complex manner than previously proposed. All replicable genetic associations display only a very modest effect. Despite of enormous research efforts, currently pharmacogenetics of therapeutic effects and of side effects of antidepressants are unable to guide decisions on the selection of the most beneficial drug for an individual patient.

Phospholipase A2 and cyclooxygenase 2 genes influence the risk of interferon-alpha-induced depression by regulating polyunsaturated fatty acids levels

BACKGROUND

Phospholipase A2 (PLA2) and cyclooxygenase 2 (COX2) are the two key enzymes in the metabolism of polyunsaturated fatty acids, which in turn play an important role in cytokine-induced depression and sickness behavior.

METHODS

Patients with chronic hepatitis C viral infection (n = 132) were assessed to examine the effects of seven single nucleotide polymorphisms in COX2 and PLA2 genes on the development of depression during interferon (IFN)-alpha treatment; a subsample (n = 63) was assessed for the erythrocyte levels of the three main polyunsaturated fatty acids, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid. An independent "replication" sample of patients with major depression unrelated to cytokine treatment (n = 82) was also examined.

RESULTS

Twenty-eight percent of participants developed INF-alpha-induced depression. Participants with the PLA2 BanI GG or the COX2 rs4648308 AG genotypes had a higher risk of IFN-alpha-induced depression (odds ratio = 3.1 and 3.5, respectively). The "at risk" PLA2 genotype was associated with lower EPA levels, and the "at risk" COX2 genotype was associated with lower DHA levels, during IFN-alpha treatment. The PLA2 BanI GG polymorphism was also associated with more somatic symptoms of depression, both in patients with INF-alpha-induced depression and in the replication sample of patients with major depression.

CONCLUSIONS

Genetic variations in the COX2 and PLA2 genes increase the risk of IFN-alpha-induced depression, possibly by affecting the levels of EPA and DHA. Moreover, PLA2 genotype is associated with somatic symptoms in depression. Our study confirms the role of inflammatory mechanisms in major depression.

From nature versus nurture, via nature and nurture, to gene x environment interaction in mental disorders

It is now generally accepted that complex mental disorders are the results of interplay between genetic and environmental factors. This holds out the prospect that by studying G x E interplay we can explain individual variation in vulnerability and resilience to environmental hazards in the development of mental disorders. Furthermore studying G x E findings may give insights in neurobiological mechanisms of psychiatric disorder and so improve individualized treatment and potentially prevention. In this paper, we provide an overview of the state of field with regard to G x E in mental disorders. Strategies for G x E research are introduced. G x E findings from selected mental disorders with onset in childhood or adolescence are reviewed [such as depressive disorders, attention-deficit/hyperactivity disorder (ADHD), obesity, schizophrenia and substance use disorders]. Early seminal studies provided evidence for G x E in the pathogenesis of depression implicating 5-HTTLPR, and conduct problems implicating MAOA. Since then G x E effects have been seen across a wide range of mental disorders (e.g., ADHD, anxiety, schizophrenia, substance abuse disorder) implicating a wide range of measured genes and measured environments (e.g., pre-, peri- and postnatal influences of both a physical and a social nature). To date few of these G x E effects have been sufficiently replicated. Indeed meta-analyses have raised doubts about the robustness of even the most well studied findings. In future we need larger, sufficiently powered studies that include a detailed and sophisticated characterization of both phenotype and the environmental risk.

Genetic bases of comorbidity between mood disorders and migraine: possible role of serotonin transporter gene

Migraine is a common neurological disease in the population and the most associated headache with mood disorder. Although the relationship between migraine and depression is well known, the reverse correlation between depression and migraine was observed but not well understood. The tight relationship between the two disturbances is also suggested by the efficacy of antidepressants for migraine treatment. Starting from these observations, we can presume that both migraine and depression have overlapping biological bases. The main target of antidepressant treatments belonging to the serotonin selective reuptake inhibitors (SSRI) type is the serotonin transporter (SERT); a well-studied polymorphic variant, in the promoter region of the gene (SERTPR), has been demonstrated to influence the availability of serotonin in the synaptic cleft. So, our group studied the possible role of the SERT as a risk factor, both for migraine and mood disorders, in a sample of 96 patients affected by both pathologies.

Moderation of antidepressant response by the serotonin transporter gene

BACKGROUND

There have been conflicting reports on whether the length polymorphism in the promoter of the serotonin transporter gene (5-HTTLPR) moderates the antidepressant effects of selective serotonin reuptake inhibitors (SSRIs). We hypothesised that the pharmacogenetic effect of 5-HTTLPR is modulated by gender, age and other variants in the serotonin transporter gene.

AIMS

To test the hypothesis that the 5-HTTLPR differently influences response to escitalopram (an SSRI) compared with nortriptyline (a noradrenaline reuptake inhibitor).

METHOD

The 5-HTTLPR and 13 additional markers across the serotonin transporter gene were genotyped in 795 adults with moderate-to-severe depression treated with escitalopram or nortriptyline in the Genome Based Therapeutic Drugs for Depression (GENDEP) project.

RESULTS

The 5-HTTLPR moderated the response to escitalopram, with long-allele carriers improving more than short-allele homozygotes. A significant three-way interaction between 5-HTTLPR, drug and gender indicated that the effect was concentrated in males treated with escitalopram. The single-nucleotide polymorphism rs2020933 also influenced outcome.

CONCLUSIONS

The effect of 5-HTTLPR on antidepressant response is SSRI specific conditional on gender and modulated by another polymorphism at the 5' end of the serotonin transporter gene.

5-HT2A gene variants influence specific and different aspects of antidepressant response in Japanese and Italian mood disorder patients

The 5-HT2A receptor is a key modulator of the serotonin pathway. We previously observed a marginal association between 5-HT2A gene variants and antidepressant efficacy in Japanese and Italian population but in the opposite direction. In the present report, we hypothesize that discrepant findings on 5-HT2A gene variants could be due to both the effect of ethnicity and a possible specific effect on some symptom improvement. The sample comprised 203 patients affected by mood disorders and treated for major depression with paroxetine or fluvoxamine. The total depressive scores for all patients were analyzed in previous reports, but symptomatologic clusters were not examined previously. The 21-item Hamilton Rating Scale for Depression (HAM-D) was administered to evaluate depressive symptoms at baseline and bi-weekly over 6 weeks of treatment. All patients were genotyped for the 5-HT2A T102C polymorphism. Compared with patients with the 5-HT2A T and C variants, in the Japanese sample T allele carriers showed selective and slower score reductions than C allele carriers in delusion and activity symptoms; on the other hand, in the Italian sample, C allele carriers showed a slower and selective score reduction compared with T allele carriers in Somatic anxiety, while they did not differ from other patients on the other scores. Despite the limitations of the small sample size and modest significance levels, these findings suggest that response to SSRIs is not a unitary phenomenon and discrepant findings across ethnic groups may be due to differential effects of gene variants.

Differential effects of 5-HTTLPR genotypes on mood, memory, and attention bias following acute tryptophan depletion and stress exposure

RATIONALE

Polymorphisms of the serotonin transporter gene (5-HTTLPR) may be associated with increased vulnerability to acute tryptophan depletion (ATD) and depression vulnerability especially following stressful life events.

OBJECTIVE

The aim of the present study was to investigate the effects of ATD in subjects with different 5-HTTLPR profiles before and after stress exposure on affective and cognitive-attentional changes.

MATERIALS AND METHODS

Eighteen subjects with homozygotic short alleles (S'/S') and 17 subjects with homozygotic long alleles (L'/L') of the 5-HTTLPR participated in a double-blind, placebo-controlled, crossover design to measure the effects of ATD on mood, memory, and attention before and after acute stress exposure.

RESULTS

ATD lowered mood in all subjects independent of genotype. In S'/S' genotypes, mild acute stress increased depressive mood and in L'/L' genotypes increased feelings of vigor. Furthermore, S'/S' genotypes differed from L'/L' genotypes on measures of attention independent of treatment and memory following ATD.

CONCLUSIONS

Polymorphisms of the 5-HTTLPR differentially affect responses to mild stress and ATD, suggesting greater vulnerability of S'/S' carriers to serotonergic manipulations and supporting increased depression vulnerability.

Differential efficacy of escitalopram and nortriptyline on dimensional measures of depression

BACKGROUND

Tricyclic antidepressants and serotonin reuptake inhibitors are considered to be equally effective, but differences may have been obscured by internally inconsistent measurement scales and inefficient statistical analyses.

AIMS

To test the hypothesis that escitalopram and nortriptyline differ in their effects on observed mood, cognitive and neurovegetative symptoms of depression.

METHOD

In a multicentre part-randomised open-label design (the Genome Based Therapeutic Drugs for Depression (GENDEP) study) 811 adults with moderate to severe unipolar depression were allocated to flexible dosage escitalopram or nortriptyline for 12 weeks. The weekly Montgomery-Asberg Depression Rating Scale, Hamilton Rating Scale for Depression, and Beck Depression Inventory were scored both conventionally and in a more novel way according to dimensions of observed mood, cognitive symptoms and neurovegetative symptoms.

RESULTS

Mixed-effect linear regression showed no difference between escitalopram and nortriptyline on the three original scales, but symptom dimensions revealed drug-specific advantages. Observed mood and cognitive symptoms improved more with escitalopram than with nortriptyline. Neurovegetative symptoms improved more with nortriptyline than with escitalopram.

CONCLUSIONS

The three symptom dimensions provided sensitive descriptors of differential antidepressant response and enabled identification of drug-specific effects.