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1.  Frontal and Limbic Activation During Inhibitory Control Predicts Treatment Response in Major Depressive Disorder 
Biological psychiatry  2007;62(11):1272-1280.
Inhibitory control or regulatory difficulties have been explored in major depressive disorder (MDD) but typically in the context of affectively salient information. Inhibitory control is addressed specifically by using a task devoid of affectively-laden stimuli, to disentangle the effects of altered affect and altered inhibitory processes in MDD.
Twenty MDD and 22 control volunteer participants matched by age and gender completed a contextual inhibitory control task, the Parametric Go/No-go (PGNG) task during functional magnetic resonance imaging. The PGNG includes three levels of difficulty, a typical continuous performance task and two progressively more difficult versions including Go/No-go hit and rejection trials. After this test, 15 of 20 MDD patients completed a full 10-week treatment with s-citalopram.
There was a significant interaction among response time (control subjects better), hits (control subjects better), and rejections (patients better). The MDD participants had greater activation compared with the control group in frontal and anterior temporal areas during correct rejections (inhibition). Activation during successful inhibitory events in bilateral inferior frontal and left amygdala, insula, and nucleus accumbens and during unsuccessful inhibition (commission errors) in rostral anterior cingulate predicted post-treatment improvement in depression symptoms.
The imaging findings suggest that in MDD subjects, greater neural activation in frontal, limbic, and temporal regions during correct rejection of lures is necessary to achieve behavioral performance equivalent to control subjects. Greater activation in similar regions was further predictive of better treatment response in MDD.
PMCID: PMC2860742  PMID: 17585888
Depression; executive functioning; fMRI; imaging; inhibitory control; mood disorders; SSRIs; treatment response
2.  The V103I polymorphism of the MC4R gene and obesity: population based studies and meta-analysis of 29 563 individuals 
Previous studies have suggested that a variant in the melanocortin-4 receptor (MC4R) gene is important in protecting against common obesity. Larger studies are needed, however, to confirm this relation.
We assessed the association between the V103I polymorphism in the MC4R gene and obesity in three UK population based cohort studies, totalling 8,304 individuals. We also did a meta-analysis of relevant studies, involving 10,975 cases and 18,588 controls, to place our findings in context.
In an analysis of all studies, individuals carrying the isoleucine allele had an 18% (95% CI 4-30%, p=0·015) lower risk of obesity compared with noncarriers. There was no heterogeneity among studies and no apparent publication bias.
This study confirms that the V103I polymorphism protects against human obesity at a population level. As such it provides proof of principle that specific gene variants may, at least in part, explain susceptibility and resistance to common forms of human obesity. A better understanding of the mechanisms underlying this association will help determine whether changes in MC4R activity have therapeutic potential.
PMCID: PMC2683751  PMID: 17356525
3.  Influences of Hormone-Based Contraception on Depressive Symptoms in Premenopausal Women with Major Depression 
Psychoneuroendocrinology  2007;32(7):843-853.
Hormone-based contraceptives affect mood in healthy women or in women with Premenstrual Dysphoric Disorder. No study has yet examined their association with mood in women with major depressive disorder (MDD). The purpose of this study was to determine whether estrogen-progestin combination or progestin-only contraceptives are associated with depression severity, function and quality of life, or general medical or psychiatric comorbidity in women with MDD.
This analysis focused on a large population of female outpatients less than 40 years of age with non-psychotic MDD who were treated in 18 primary and 23 psychiatric care settings across the United States, using data from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. Baseline demographic and clinical information was gathered and compared between three groups based on hormonal use: combination (estrogen-progestin)(N=232), progestin-only (N=58), and no hormone treatment (N=948).
Caucasians were significantly more likely to use combined hormone contraception. Women on progestin-only had significantly more general medical comorbidities; greater hypersomnia, weight gain and gastrointestinal symptoms; and worse physical functioning than women in either of the other groups. Those on combined hormone contraception were significantly less depressed than those with no hormone treatment by the 16-item Quick Inventory of Depressive Symptomatology - Self-Rated. The combined hormone group also demonstrated better physical functioning and less obsessive-compulsive disorder comorbidity than either of the other groups.
Synthetic estrogen and progestins may influence depressive and physical symptoms in depressed women.
PMCID: PMC2100423  PMID: 17629629
Estradiol; Progesterone; Major Depression; Mood symptoms; Oral contraceptives; Norplant
4.  Sex Differences in ACTH Pulsatility following Metyrapone Blockade in Patients with Major Depression 
Psychoneuroendocrinology  2007;32(5):503-507.
Numerous studies suggest that increased central drive to the hypothalamic-pituitary adrenal axis occurs in patients with major depression. To determine if increased central drive occurs throughout the 24H, we evaluated ACTH secretion under metyrapone blockade of cortisol production. We collected blood every 10 minutes for measurement of ACTH and data were analyzed for ACTH pulsatility using the pulse detection algorithm deconvolution. We studied 28 patients with major depression and 28 age and sex matched control subjects, of which 9 pairs were men and 19 pairs were women. We found a significant group by sex interaction with number of ACTH pulses (p=.04); depressed men showed more ACTH pulses over 24H than matched control men (p=0.02). There was also a significant sex difference in AUC pulses with men showing a smaller AUC ACTH than women. Previous analyses of these data with RM-ANOVA showed a smaller ACTH response in depressed men compared to control men. These data suggest that pulsatility and mean ACTH levels are examining different aspects of HPA axis function, and that the types of HPA axis dysregulation in depression may differ between men and women.
PMCID: PMC1975691  PMID: 17462829
depression; ACTH; Hormone pulsatility; stress; HPA axis; cortisol
5.  Three novel mutations in KIF21A highlight the importance of the third coiled-coil stalk domain in the etiology of CFEOM1 
BMC Genetics  2007;8:26.
Congenital fibrosis of the extraocular muscles types 1 and 3 (CFEOM1/CFEOM3) are autosomal dominant strabismus disorders that appear to result from maldevelopment of ocular nuclei and nerves. We previously reported that most individuals with CFEOM1 and rare individuals with CFEOM3 harbor heterozygous mutations in KIF21A. KIF21A encodes a kinesin motor involved in anterograde axonal transport, and the familial and de novo mutations reported to date predictably alter one of only a few KIF21A amino acids – three within the third coiled-coil region of the stalk and one in the distal motor domain, suggesting they result in altered KIF21A function. To further define the spectrum of KIF21A mutations in CFEOM we have now identified all CFEOM probands newly enrolled in our study and determined if they harbor mutations in KIF21A.
Sixteen CFEOM1 and 29 CFEOM3 probands were studied. Three previously unreported de novo KIF21A mutations were identified in three CFEOM1 probands, all located in the same coiled-coil region of the stalk that contains all but one of the previously reported mutations. Eight additional CFEOM1 probands harbored three of the mutations previously reported in KIF21A; seven had one of the two most common mutations, while one harbored the mutation in the distal motor domain. No mutation was detected in 5 CFEOM1 or any CFEOM3 probands.
Analysis of sixteen CFEOM1 probands revealed three novel KIF21A mutations and confirmed three reported mutations, bringing the total number of reported KIF21A mutations in CFEOM1 to 11 mutations among 70 mutation positive probands. All three new mutations alter amino acids in heptad repeats within the third coiled-coil region of the KIF21A stalk, further highlighting the importance of alterations in this domain in the etiology of CFEOM1.
PMCID: PMC1888713  PMID: 17511870

Results 1-5 (5)