Pharmacogenetics of selective serotonin reuptake inhibitors in pediatric depression and anxiety

The Role of MAPK and Dopaminergic Synapse Signaling Pathways in Antidepressant Effect of Electroacupuncture Pretreatment in Chronic Restraint Stress Rats

Acupuncture has demonstrated the function in ameliorating depressive-like behaviors via modulating PKA/CREB signaling pathway. To further confirm the antidepressant mechanism of EA on the mitogen-activated protein kinase (MAPK) and dopaminergic synapse signaling pathways, 4 target proteins were detected based on our previous iTRAQ analysis. Rats were randomly divided into control group, model group, and electroacupuncture (EA) group. Except for the control group, all rats were subjected to 28 days of chronic restraint stress (CRS) protocols to induce depression. In the EA group, EA pretreatment at Baihui (GV20) and Yintang (GV29) was performed daily (1 mA, 2 Hz, discontinuous wave, 20 minutes) prior to restraint. The antidepressant-like effect of EA was measured by body weight and open-field test. The protein levels of DAT, Th, Mapt, and Prkc in the hippocampus were examined by using Western blot. The results showed EA could ameliorate the depression-like behaviors and regulate the expression levels of Prkc and Mapt in CRS rats. The effect of EA on DAT and Th expression was minimal. These findings implied that EA pretreatment could alleviate depression through modulating MAPK signaling pathway. The role of EA on dopaminergic synapse signaling pathways needs to be further explored.

Clinically relevant pharmacogenomic testing in pediatric practice

Clinicians and patients continue to convey interest in personalized medicine. The objective of personalized medicine is to improve healthcare by tailoring disease prevention, diagnosis, and treatment strategies for individuals based on their unique clinical history and genetic composition. This article offers an overview of pharmacogenomics, discusses caveats specific to pharmacogenomics in pediatric populations, provides evidence-based recommendations for pediatric clinicians, and offers insight regarding the future role of pharmacogenomics testing in pediatric medicine. Reviews of the current literature and thoughtful discussions are presented regarding the pharmacogenomics of antidepressants, codeine and oncologic, asthma, and immunomodulatory pharmacotherapies.

Plasma fluoxetine concentrations and clinical improvement in an adolescent sample diagnosed with major depressive disorder, obsessive-compulsive disorder, or generalized anxiety disorder

Fluoxetine (FLX) has been one of the most widely studied selective serotonin reuptake inhibitors in adolescents. Despite its efficacy, however, 30% to 40% of patients do not respond to treatment.

AIMS

The aim of this study was to evaluate whether clinical improvement or adverse events are related to the corrected dose of FLX at 8 and 12 weeks after starting treatment in a sample of adolescents diagnosed with major depressive disorder, obsessive-compulsive disorder, or generalized anxiety disorder.

METHODS

Seventy-four subjects aged between 10 and 17 years participated in the study. Clinical improvement was measured with the Clinical Global Impression-Improvement Scale, whereas the UKU (Udvalg for Klinske Undersogelser) scale was administered to assess adverse effects of treatment.

RESULTS

Fluoxetine per kilograms of body weight was related to serum concentration of FLX, NORFLX (norfluoxetine), FLX + NORFLX, and FLX/NORFLX. No relationship was found between dose-corrected FLX levels and therapeutic or adverse effects. No differences in serum concentrations were found between responders and nonresponders to treatment. Sex differences were observed in relation to dose and FLX serum concentration. The analysis by diagnosis revealed differences in FLX dose between obsessive-compulsive disorder patients and both generalized anxiety disorder and major depressive disorder patients.

CONCLUSIONS

Fluoxetine response seems to be influenced by factors such as sex, diagnosis, or certain genes that might be involved in the drug's pharmacokinetics and pharmacodynamics. Clinical and pharmacogenetic studies are needed to elucidate further the differences between treatment responders and nonresponders.

The pharmacokinetic-pharmacodynamic model of azithromycin for lipopolysaccharide-induced depressive-like behavior in mice

A mechanism-based model was developed to describe the time course of lipopolysaccharide-induced depressive-like behavior and azithromycin pharmacodynamics in mice. The lipopolysaccharide-induced disease progression was monitored by lipopolysaccharide, proinflammatory cytokines, and kynrenine concentration in plasma. The depressive-like behavior was investigated by forced swimming test and tail suspension test. Azithromycin was selected to inhibit the surge of proinflammatory cytokines induced by lipopolysaccharide. Disease progression model and azithromycin pharmacodynamics were constructed from transduction and indirect response models. A delay in the onset of increased proinflammatory cytokines, kynrenine, and behavior test compared to lipopolysaccharide was successfully characterized by series transduction models. The inhibition of azithromycin on proinflammatory cytokines was described by an indirect response model. After lipopolysaccharide challenging, the proinflammatory cytokines, kynrenine and behavior tests would peak approximately at 3, 12, and 24 h respectively, and then the time courses slowly declined toward a baseline state after peak response. During azithromycin administration, the peak levels of proinflammatory cytokines, kynrenine and behavior indexes decreased. Model parameters indicated that azithromycin significantly inhibited the proinflammatory cytokines level in plasma and improved the depressive-like behavior induced by inflammation. The integrated model for disease progression and drug intervention captures turnovers of proinflammatory cytokines, kynrenine and the behavior results in the different time phases and conditions.

Allele-specific associations of 5-HTTLPR/rs25531 with ADHD and autism spectrum disorder

BACKGROUND

The aims of the present study were to examine the association between a common serotonin transporter gene (SLC6A4) polymorphism 5-HTTLPR/rs25531 with severity of attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) symptoms.

METHODS

Mothers and teachers completed a validated DSM-IV-referenced rating scale for ADHD and ASD symptoms in 118 children with ASD.

RESULTS

Analyses indicated that children with at least one copy of the S or L(G) allele obtained significantly more severe maternal ratings of hyperactivity (p=0.001; ηp(2)=0.097) and impulsivity (p=0.027; ηp(2)=0.044) but not inattention (p=0.061; ηp(2)=0.032), controlling for ASD severity, than children homozygous for the L(A) allele. Conversely, mothers' ratings indicated that children with L(A)/L(A) genotype had more severe ASD social deficits than S or L(G) allele carriers (p=0.003; ηp(2)=0.081), controlling for ADHD symptom severity. Teachers' ratings though consistent with mothers' ratings of hyperactivity and social deficits were marginally significant (p=0.07/p=0.09). There was some evidence that the magnitude of parent-teacher agreement regarding symptom severity varied as a function of the child's genotype.

CONCLUSION

The 5-HTTLPR/rs25531 polymorphism or its correlates may modulate severity of ADHD and ASD symptoms in children with ASD, but in different ways. These tentative, hypothesis-generating findings require replication with larger independent samples.

Fluoxetine pharmacogenetics in child and adult populations

Although fluoxetine is useful in the treatment of major depression, 30-40 % of the patients do not respond to therapy. The response seems to be influenced by certain genes which are involved in the drug's pharmacodynamics and pharmacokinetics. The present study reviews the literature on genetic contributions to fluoxetine response in children and adults, and concludes that the different polymorphisms of CYP2D6 and CYP2C9 may influence the blood concentrations of fluoxetine. If the childhood dose is adjusted for weight, differences between children and adults are unlikely. As regards the genes that influence the drug's pharmacodynamics, polymorphisms of SLC6A4, HTR1A and MAO-A seem to be involved in the response to fluoxetine, while the genes COMT, CRHR1, PDEA1, PDEA11 GSK3B and serpin-1 also seem to play a role. Comparison of different studies reveals that the results are not always consistent, probably due to methodological differences. Other factors such as gender or ethnicity may also influence treatment response.

Antidepressants and adolescent brain development

Despite being a first-line treatment for adolescent depression and anxiety, antidepressant drugs appear to have questionable efficacy and carry an increased risk of adverse effects in this population. The neural mechanisms underlying this phenomenon are currently unknown. Recent research into the neural effects of alcohol and recreational drugs suggests that the developmental trajectory of the adolescent brain may be particularly vulnerable to pharmacological disturbance. It is therefore important to consider whether prescription psychotropic drugs may have analogous effects. This article reviews the contribution of recent preclinical, clinical and pharmacogenetic literature to current knowledge on the short-term and enduring neural effects of antidepressants on the adolescent brain, with a particular focus on the major neurotransmitter systems and neuroplasticity.

Long-term outcome following selective serotonin reuptake inhibitor induced neonatal abstinence syndrome

OBJECTIVE

To assess the long-term neurodevelopment of children exposed in utero to selective serotonin reuptake inhibitors (SSRIs) that developed a neonatal abstinence syndrome (NAS).

STUDY DESIGN

Neurodevelopmental evaluation was performed at the age of 2 to 6 years. Children who developed NAS were compared with those who did not using univariate and logistic regression analyses.

RESULT

Thirty children with NAS and 52 without NAS participated in the study. Both groups were similar in mean cognitive ability (106.9±14.0 vs 100.5±14.6, P=0.12) and developmental scores (98.9±11.4 vs 95.7±9.9, P=0.21). However, there was a trend towards small head circumference in the NAS group (20 vs 6%, P=0.068). NAS was associated with an increased risk of social-behavior abnormalities (odds ratio (OR) 3.03, 95% confidence interval (CI) 1.07 to 8.60, P=0.04) and advanced maternal age (OR 1.12, 95% CI 1.00 to 1.25, P=0.04).

CONCLUSION

Infants who developed NAS had normal cognitive ability, but were at an increased risk for social-behavioral abnormalities. Follow-up evaluation of symptomatic neonates should be considered.

Peripheral anti-inflammatory effects explain the ginsenosides paradox between poor brain distribution and anti-depression efficacy

Background

The effectiveness of ginseng in preventing and treating various central nervous system (CNS) diseases has been widely confirmed. However, ginsenosides, the principal components of ginseng, are characterized by poor accessibility to the brain, and this pharmacokinetic-pharmacological paradox remains poorly explained. Anti-inflammatory approaches are becoming promising therapeutic strategies for depression and other CNS diseases; however, previous studies have focused largely on anti-inflammatory therapies directed at the central nervous system. It is thus of interest to determine whether ginsenosides, characterized by poor brain distribution, are also effective in treating lipopolysaccharide- (LPS) induced depression-like behavior and neuroinflammation.

Methods

In an LPS-induced depression-like behavior model, the antidepressant effects of ginseng total saponins (GTS) were assessed using a forced swimming test, a tail suspension test, and a sucrose preference test. The anti-inflammatory efficacies of GTS in brain, plasma, and LPS-challenged RAW264.7 cells were validated using ELISA and quantitative real-time PCR. Moreover, indoleamine 2,3-dioxygenase (IDO) activity in the periphery and brain were also determined by measuring levels of kynurenine/tryptophan.

Results

GTS significantly attenuated LPS-induced depression-like behavior. Moreover, LPS-induced increases in 5-HT and tryptophane turnover in the brain were significantly reduced by GTS. IDO activities in brain and periphery were also suppressed after pretreatment with GTS. Furthermore, GTS-associated recovery from LPS-induced depression-like behavior was paralleled with reduced mRNA levels for IL-1β, IL-6, TNF-α, and IDO in hippocampus. Poor brain distribution of ginsenosides was confirmed in LPS-challenged mice. GTS treatment significantly decreased production of various proinflammatory cytokines in both LPS-challenged mice and RAW264.7 cells.

Conclusion

This study suggests that the anti-depression efficacy of GTS may be largely attributable to its peripheral anti-inflammatory activity. Our study also strengthens an important notion that peripheral anti-inflammation strategies may be useful in the therapy of inflammation-related depression and possibly other CNS diseases.

A brief DSM-IV-referenced teacher rating scale for monitoring behavioral improvement in ADHD and co-occurring symptoms

OBJECTIVE

To examine the psychometric properties of the 30-item teacher's version of the Child and Adolescent Symptom Inventory Progress Monitor (CASI-PM-T), a DSM-IV-referenced rating scale for monitoring change in ADHD and co-occurring symptoms in youths receiving behavioral or pharmacological interventions.

METHOD

Three separate studies were conducted to determine (a) which items from longer diagnostic instruments were most representative of ADHD and commonly occurring psychiatric syndromes in clinic-referred samples ( N = 406) aged between 3 and 18 years, (b) the reliability and validity of the CASI-PM-T in students enrolled in full-time special education programs at the elementary and middle school levels (N = 169), and (c) the clinical utility of measuring behavioral change in a sample of outpatient ADHD children beginning treatment with stimulant medication.

RESULTS

Internal consistency reliabilities (.71-.94), 2-week test-retest reliabilities (r = .70-.90), and interrater agreement (r = .44-.78) for the CASI-PM-T symptom categories were comparable to the full-length CASI-4. Convergence was also found between corresponding CASI-PM-T categories and consultant diagnoses of ADHD and ODD as well as school functioning measures of grade-point average and suspensions. The CASI-PM-T also demonstrated sensitivity to stimulant medication treatment effects.

CONCLUSION

Findings provide preliminary support for the reliability, validity, and clinical utility of the CASI-PM-T.

The effect of increased serotonergic neurotransmission on aggression: a critical meta-analytical review of preclinical studies

RATIONALE

The role of serotonin (5-HT) on aggression has been extensively studied; nonetheless, the role of this neurotransmitter in aggression is still inconclusive.

OBJECTIVES

The current meta-analytical review investigated the role of increased 5-HT neurotransmission in aggression.

METHODS

Preclinical studies using serotonin reuptake inhibitors, 5-hydroxytryptophan, L-tryptophan, or serotonin (5-HT) to increase 5-HT levels were included in this meta-analysis. An overall effect of serotonin on aggression was calculated, and the role of several moderator variables was analyzed.

RESULTS

A total of 218 effect sizes revealed that increased 5-HT had an overall significant inhibitory effect on aggression (r = 0.3). The results showed that increased 5-HT had the strongest inhibitory effect on aggression when (1) a specific strain or species (e.g., Long Evans) was used; (2) aggression was offensive or predatory and/or induced by administration of 5,7-dihydroxytryptamine or p-chlorophenylalanine; (3) zimelidine, sertraline, L-tryptophan, citalopram, or 5-HT were used to increase 5-HT; (4) treatment was acute; (5) long chronic treatment durations were used; and (6) time between last injection and behavior testing was within 8 h before or after peak plasma concentration of drug. In contrast, the results revealed that increased-5-HT-facilitated aggression could be predicted when (1) Wistar rats, (2) social isolation or stress to induce aggression, and/or (3) animals treated for less than 3 weeks were used.

CONCLUSIONS

Although 5-HT has an overall inhibitory effect on aggression, the animal's genetic background, drug, treatment time, aggression inducing paradigm, and aggression type are critical variables that influence and modify this effect.

When, why, and how to conduct research in child and adolescent psychiatry: practical and ethical considerations

Changes in the clinical research enterprise to involve practicing psychiatrists in gathering evidence in real-world settings are truly exciting. The CAPTN breaks important ground as a PBRN in psychiatry. The authors anticipate that more practical clinical trials will come. These changes challenge psychiatrists to reach an entirely new level of understanding and appreciation of the ethical and practical challenges of commingling clinical practice and research. It is time that all practicing psychiatrists prepare to meet these challenges.