Charles J. George

Hypothalamic-pituitary-adrenal axis dysregulation in depressed children and adolescents: a meta-analysis.

Research findings on the hypothalamic-pituitary-adrenal (HPA) axis and pediatric depression reflect a variety of methodological approaches that tap different facets of HPA-axis functions. Partly owing to the methodological heterogeneity of studies, descriptive reviews of this area have produced inconsistent conclusions. Therefore, we conducted formal meta-analyses of pertinent studies in order to advance our understanding of HPA-axis dysregulation in pediatric depression. We examined: (a) 17 published studies of HPA-axis response to the dexamethasone suppression test (DST) in depressed youth (DST; N=926) and (b) 17 studies of basal HPA-axis functioning (N=1332). We also examined descriptively studies that used corticotropin-releasing hormone (CRH) infusion, and those that used psychological probes of the HPA-axis. The global standardized mean effect size difference in HPA-axis response to the DST between depressed and non-depressed youth was 0.57, z=4.18, p<0.01. The global standardized mean difference effect size in basal HPA-axis functioning was 0.20, z=4.53, p<0.01. Age, sex, timing of sampling, dexamethasone dosage, or type of control group was not a significant source of variability for the DST or basal studies. In addition, when compared to non-depressed peers, depressed youth have a normative response to CRH infusion but an overactive response to psychological stressors. In conclusion, the HPA-axis system tends to be dysregulated in depressed youth, as evidenced by atypical responses to the DST, higher baseline cortisol values, and an overactive response to psychological stressors. This pattern of dysregulation suggests anomalies within the axiss negative feedback system and CRH production, but intact pituitary and adrenal sensitivity.

Brain-derived neurotrophic factor variants are associated with childhood-onset mood disorder: confirmation in a Hungarian sample

Brain-derived neurotrophic factor (BDNF) is a nerve growth factor that has been implicated in the neurobiology of depression. Our group has previously reported an association between a BDNF variant and childhood-onset mood disorder (COMD) in an adult sample from Pittsburgh. We hypothesize that variants at the BDNF locus are associated with COMD. Six BDNF polymorphisms were genotyped in 258 trios having juvenile probands with childhood-onset DSM-IV major depressive or dysthymic disorder. BDNF markers included the (GT)n microsatellite, Val66Met and four other single-nucleotide polymorphisms (SNPs) distributed across the BDNF gene. Family-based association and evolutionary haplotype analysis methods were used. Analysis of linkage disequilibrium (LD) revealed substantial LD among all six polymorphisms. Analyses of the Val66Met polymorphism demonstrated significant overtransmission of the val allele (χ2=7.12, d.f.=1, P=0.0076). Consistent with the pattern of LD, all other SNPs showed significant biased transmission. The (GT)n microsatellite alleles also indicated a trend towards biased transmission (170 bp: Z=2.095, P=0.036). Significant haplotypes involved Val66Met and BDNF2 (P=0.0029). In this Hungarian sample, we found all five BDNF SNPs tested and a haplotype containing the BDNF Val66Met Val allele to be associated with COMD. These results provide evidence that BDNF variants affect liability to juvenile-onset mood disorders, supported by data from two independent samples.

Association study of brain-derived neurotrophic factor in adults with a history of childhood onset mood disorder

Brain‐derived neurotrophic factor (BDNF) is a nerve growth factor that has antidepressant‐like effects in animals. BDNF gene polymorphisms have been associated with bipolar disorder. We tested two genetic polymorphisms of BDNF for their association with childhood‐onset mood disorders (COMD) within the context of a case‐control design. Two BDNF polymorphisms, a dinucleotide repeat (GT)n, and a single nucleotide polymorphism (SNP) in the coding region, val66met, were genotyped in 99 adults with a history of COMD and matched psychiatrically healthy controls. A genomic control (GC) method was used to evaluate population substructure. Alleles at (GT)n were highly associated with COMD in this sample (χ2 = 17.8; d.f. = 5; P = 0.0032). The odds of carrying the 168 bp allele were 3.94 times greater for cases than controls (CI = 1.72–9.04). Alleles of val66met were not significantly associated with COMD. GC analysis suggested population substructure was not a confounder of association. Analysis of haplotypes, in which (GT)n was treated as a binary variable (long vs. short alleles), provided significant evidence that the haplotype val/short contributes to liability to COMD. The BDNF (GT)n marker and the val/short haplotype are associated with COMD in this sample, in accordance with the previously described neurotrophic hypothesis of depression and some previous studies of association for bipolar disorder and neuroticism. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148‐7299:1/suppmat/index.html.

One-Year Follow-Up of The Stent Restenosis (STRESS I) Study

We present the completed 1-year follow-up results of the original Stent Restenosis Study (STRESS I), in which 407 patients with symptomatic ischemic heart disease and new lesions of the native coronary circulation were randomly assigned to treatment with either the Palmaz-Schatz coronary stent or conventional percutaneous transluminal coronary angioplasty (PTCA). The present study compares the safety of elective stenting to balloon angioplasty (PTCA) in terms of freedom from clinical events up to 1 year after treatment. Patients were enrolled and treated from January 1991 through February 1993, and follow-up data were collected and verified until July 1995. Ninety-seven percent of all patients had complete follow-up (deceased or alive with known clinical status) beyond 8 months, and 94% beyond 11 months. Anginal status between 9 to 15 months postprocedure was available for 78% of patients. At 1 year, 154 patients (75%) assigned to stent implantation and 141 (70%) to PTCA were free of all clinical events (death, myocardial infarction, or any revascularization procedure), and 162 stent patients (79%) and 149 PTCA patients (74%) were free from death, myocardial infarction, or target lesion revascularization. Symptom-driven target lesion revascularization occurred in 12% of the stent group versus 17% of the PTCA group. None of these differences in clinical events was statistically significant. Only 2 patients in the stent group and 7 in the PTCA group had a first event after 239 days, and freedom from angina at 1 year was reported in equal frequency in both groups (84%). There appear to be no late adverse effects of stent implantation. However, these results are limited by low statistical power, narrow patient selection, and the anticoagulation regimen used in the early experience with this device.

Developmental trajectories of positive and negative affect in children at high and low familial risk for depressive disorder

BACKGROUND Although low positive affect (PA) and high negative affect (NA) have been posited to predispose to depressive disorders, little is known about the developmental trajectories of these affects in children at familial risk for mood disorders. METHODS We examined 202 offspring of mothers who had a history of juvenile-onset unipolar depressive disorder (n = 60) or no history of major psychopathology (n = 80). Offspring participated in up to seven annual, structured laboratory tasks that were designed to elicit PA and NA. RESULTS Growth curve analyses revealed that PA increased linearly and similarly for all children from late infancy through age 9. However, there also were individual differences in early PA. Relative to control peers, offspring of mothers with lifetime unipolar depression had consistently lower levels of PA, and this association remained significant even when controlling for current maternal depression and maternal affect displays. Growth curve analyses also revealed a significant linear decrease in NA in children across time; however, there was no significant inter-individual variation either in early NA or rate of change in NA. CONCLUSION Attenuated PA (rather than excessive NA) may be an early vulnerability factor for eventual unipolar depressive disorder in at-risk children and may represent one pathway through which depression is transmitted.

Stressful life events, social rhytms, and depressive symptoms among the elderly: An examination of hypothesized causal linkages

This study sought to determine possible causal linkages among stressful life events, social rhythms, and levels of depressive symptomatology for 81 elderly subjects (51 recently widowed, 30 healthy controls). We examined the associations among stressful life events (i.e., bereavement status at baseline or a severely threatening event occurring between baseline and followup), social rhythm stability, and the level of depressive symptoms. Results indicated that while stressful life events were not associated with significant changes in social rhythm stability, social rhythm stability was a significant negative correlate of both baseline and followup levels of depressive symptomatology; that is, lower levels of social rhythm stability at baseline were associated with high levels of depressive symptoms at baseline (rho = -0.33, n = 81, p < 0.001) and at followup (rho = -0.23, n = 81, p < 0.05). Bereavement was also a significant positive correlate of depressive symptomatology both at baseline (rho = 0.79, n = 81), p < 0.0001) and at followup (rho = 0.55, n = 81, p < 0.0001). It is likely that future research will benefit from social rhythm assessment obtained temporally closer to major life events and from the use of structured interviews to ascertain the presence of syndromal major depression at followup as well as the inclusion of subjects with a wider range of functional impairments. Nevertheless, these results represent a first step in disentangling possible causal connections among stressful life events, social rhythms, and depressive symptomatology.

BDNF and COMT polymorphisms: relation to memory phenotypes in young adults with childhood-onset mood disorder.

Recent investigations in several species have suggested a role for brain-derived neurotrophic factor (BDNF) in memory, which may be mediated by the influence of BDNF on neuronal plasticity in the hippocampus. BDNF polymorphisms have also been associated with mood disorders. Catechol-O-methyltransferase (COMT) metabolizes dopamine and has been implicated in prefrontal function, another area of the brain relevant for memory. In a sample of 63 young adults with a history of childhood-onset mood disorder, we typed three BDNF polymorphisms, including the BDNF Val66Met single nucleotide polymorphism (SNP), and the COMT Val108/158Met SNP. Multivariate analysis of variance was used to test the association between BDNF and COMT markers and measures of declarative memory. Variants at the three BDNF markers and one COMT marker were not associated with declarative memory function—p-values ranged from 0.25 to 0.98. Higher IQ (F=6.18, df=4, 58, p=0.0003) and female gender (F=4.41, df=4, 58, p=0.0035) were associated with more optimal performance on the memory tasks. This study did not provide evidence supporting an association between BDNF and COMT genes and declarative memory phenotypes.

Longitudinal Analysis of Nortriptyline Side Effects in Elderly Depressed Patients

Forty-five depressed elderly patients were closely monitored in a research setting during treatment with nortriptyline and interpersonal psychotherapy for 7 consecutive months of acute and continuation treatment. Overall, nortriptyline was efficacious and well tolerated in this group. The frequency of somatic complaints measured by the Rating Scale for Side Effects declined by 50% during the acute phase of treatment, suggesting that many somatic complaints that may be attributed to side effects of nortriptyline are actually somatic symptoms of depression. The authors discuss the implications of these findings and offer practical advice for the treating clinician. (J Geriatr Psychiatry Neurol 1991;4:226-230).

Electroencephalographic sleep in recently remitted, elderly depressed patients in double-blind placebo-maintenance therapy

The aim of this double-blind placebo-controlled study was to assess the effects of clinical state on electroencehalographic (EEG) sleep measures in elderly patients with recurrent major depression. We hypothesized that rapid-eye movement (REM) latency and delta sleep ratio would remain stable between actively depressed and remitted states (i.e., show state independence), and measures of sleep continuity would improve with remission (i.e., show state dependence). Fifteen elderly outpatients (mean age 65.3 years) had sleep evaluations while ill and afer remission, an average of 38 weeks later. All patients were in a double-blind placebo-maintenance condition at the time of follow-up studies. The major fndings were: 1) no significant change in either REM latency or delta sleep ratio; 2) reduction in early morning awakening; and 3) improvement in subjective sleep quality despite the stability of most polysomnographic measures. We conclude that REM latency and delta sleep ratio are state-independent in patients with late-life depression, and that early morning awakening and sleep quality improve with remission of symptoms. These findings suggest that EEG sleep changes may have significance for understanding the longitudinal course of depression in late life.

Frontal EEG asymmetry moderates the effects of stressful life events on internalizing symptoms in children at familial risk for depression

This study examined whether frontal alpha electroencephalographic (EEG) asymmetry moderates the association between stressful life events and depressive symptoms in children at familial risk for depression. Participants included 135 children ages 6 to 13, whose mothers had either a history of depression or no history of major psychiatric conditions. Frontal EEG was recorded while participants watched emotion-eliciting films. Symptoms and stressful life events were obtained via the Child Behavior Check List and a clinical interview, respectively. High-risk children displayed greater relative right lateral frontal activation (F7/F8) than their low-risk peers during the films. For high-risk children, greater relative left lateral frontal activation moderated the association between stressful life events and internalizing symptoms. Specifically, greater relative left lateral frontal activation mitigated the effects of stress in at-risk children.