Publications (17) View all
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Article: Effects of yoga on the autonomic nervous system, gamma-aminobutyric-acid, and allostasis in epilepsy, depression, and post-traumatic stress disorder.
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ABSTRACT: A theory is proposed to explain the benefits of yoga practices in diverse, frequently comorbid medical conditions based on the concept that yoga practices reduce allostatic load in stress response systems such that optimal homeostasis is restored. It is hypothesized that stress induces (1) imbalance of the autonomic nervous system (ANS) with decreased parasympathetic nervous system (PNS) and increased sympathetic nervous system (SNS) activity, (2) underactivity of the gamma amino-butyric acid (GABA) system, the primary inhibitory neurotransmitter system, and (3) increased allostatic load. It is further hypothesized that yoga-based practices (4) correct underactivity of the PNS and GABA systems in part through stimulation of the vagus nerves, the main peripheral pathway of the PNS, and (5) reduce allostatic load. Depression, epilepsy, post traumatic stress disorder (PTSD), and chronic pain exemplify medical conditions that are exacerbated by stress, have low heart rate variability (HRV) and low GABAergic activity, respond to pharmacologic agents that increase activity of the GABA system, and show symptom improvement in response to yoga-based interventions. The observation that treatment resistant cases of epilepsy and depression respond to vagal nerve stimulation corroborates the need to correct PNS underactivity as part of a successful treatment plan in some cases. According to the proposed theory, the decreased PNS and GABAergic activity that underlies stress-related disorders can be corrected by yoga practices resulting in amelioration of disease symptoms. This has far-reaching implications for the integration of yoga-based practices in the treatment of a broad array of disorders exacerbated by stress.Medical Hypotheses 02/2012; 78(5):571-9. · 1.39 Impact Factor -
Article: Effects of yoga versus walking on mood, anxiety, and brain GABA levels: a randomized controlled MRS study.
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ABSTRACT: Yoga and exercise have beneficial effects on mood and anxiety. γ-Aminobutyric acid (GABA)-ergic activity is reduced in mood and anxiety disorders. The practice of yoga postures is associated with increased brain GABA levels. This study addresses the question of whether changes in mood, anxiety, and GABA levels are specific to yoga or related to physical activity. Healthy subjects with no significant medical/psychiatric disorders were randomized to yoga or a metabolically matched walking intervention for 60 minutes 3 times a week for 12 weeks. Mood and anxiety scales were taken at weeks 0, 4, 8, 12, and before each magnetic resonance spectroscopy scan. Scan 1 was at baseline. Scan 2, obtained after the 12-week intervention, was followed by a 60-minute yoga or walking intervention, which was immediately followed by Scan 3. The yoga subjects (n = 19) reported greater improvement in mood and greater decreases in anxiety than the walking group (n = 15). There were positive correlations between improved mood and decreased anxiety and thalamic GABA levels. The yoga group had positive correlations between changes in mood scales and changes in GABA levels. The 12-week yoga intervention was associated with greater improvements in mood and anxiety than a metabolically matched walking exercise. This is the first study to demonstrate that increased thalamic GABA levels are associated with improved mood and decreased anxiety. It is also the first time that a behavioral intervention (i.e., yoga postures) has been associated with a positive correlation between acute increases in thalamic GABA levels and improvements in mood and anxiety scales. Given that pharmacologic agents that increase the activity of the GABA system are prescribed to improve mood and decrease anxiety, the reported correlations are in the expected direction. The possible role of GABA in mediating the beneficial effects of yoga on mood and anxiety warrants further study.Journal of alternative and complementary medicine (New York, N.Y.) 11/2010; 16(11):1145-52. · 1.69 Impact Factor -
Article: Open label trial of the tolerability and efficacy of zonisamide in the treatment of alcohol dependence.
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ABSTRACT: The objectives of this study are to assess the tolerability and efficacy of the anticonvulsant zonisamide in an open label trial of the treatment of alcohol dependence. In this trial, zonisamide (400-mg daily) was administered to alcohol-dependent subjects (ADS) (n = 16) over 13 weeks. The mean daily consumption of standard alcoholic drinks and performance on a verbal fluency task, the COWAT, and on a measure of attention and visuomotor speed, the DSMT were assessed, and the occurrence of adverse events was monitored weekly. The mean number of drinks consumed daily was significantly reduced from baseline levels during the treatment period. Performances on the COWAT and on the DSMT were not significantly reduced by zonisamide treatment. Overall, zonisamide was well tolerated by the study subjects. These results indicate that zonisamide administration may not impair verbal fluency in ADS, and are consistent with other studies that found zonisamide administration may reduce alcohol intake.The American Journal of Drug and Alcohol Abuse 03/2010; 36(2):102-5. · 1.55 Impact Factor -
Article: Reduced Plasma Nitric Oxide End Products in Cocaine-dependent Men.
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ABSTRACT: Chronic cocaine abusers experience brain and peripheral vascular dysfunction, the severity of which tends to be greater in men than women. The mechanisms underlying these effects of cocaine are unknown. Because nitric oxide (NO) abnormalities play key roles in development of vascular dysfunction in several disorders, we determined whether vascular nitric oxide end product (NOx) levels, which can serve as markers of systemic vascular NO production, are reduced in cocaine-dependent (CD) subjects. Plasma samples from 24 CD men, 12 CD women, and matched comparison subjects (19 men, 14 women) were analyzed with a Sievers 280i nitric oxide chemiluminescence detection analysis system. NOx levels in comparison in women and men were 24.9 ± 6.6 and 23.3 ± 5.7 μmol/L, and in CD women and men were 22.5 ± 8.4 and 13.0 ± 9.6 μmol/L, respectively. ANCOVA analysis, adjusted for lifetime smoking, indicated group (P < 0.0005) and sex (P = 0.04) effects, both of which survived posthoc Scheffe tests. Reduced NOx levels in CD men drove the group difference. These data suggest that chronic cocaine abuse is associated with reduced NOx levels in men, although the finding also may be attributable to factors indirectly related to cocaine abuse, including cohort differences in other drug use or lifestyle factors. These findings warrant additional studies to more directly characterize vascular NO turnover in cocaine abusers and to establish whether NO abnormalities contribute to cocaine-associated vascular dysfunction and to sex differences in cocaine's effects.Journal of Addiction Medicine 06/2007; 1(2):96-103. · 1.95 Impact Factor -
Article: Functional magnetic resonance imaging of alprazolam-induced changes in humans with familial alcoholism.
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ABSTRACT: This study sought to identify whether subjects with a family history (FH + ) of alcoholism had changes in regional cerebral blood volume (rCBV) after an alprazolam challenge which distinguished them from subjects without a family history (FH -) of alcoholism using functional MRI (fMRI). Twelve FH + and eight FH - subjects were challenged with 1 mg of alprazolam or placebo in a double-blind crossover design. FMRI scans were obtained at baseline, 1 and 2 h after the challenge using the dynamic susceptibility contrast method with gadolinium. Mood scales, the Tufts Addiction Research Center Inventory-Morphine Benzedrine Group Scale and the drug liking scale, were administered every 30 min to assess drug effects. Global analysis of CBV showed a treatment by time decrease on alprazolam relative to placebo, but no effect by family history. The FH + group showed rCBV decreases at 1 h in the left caudate and left inferior prefrontal region, while the FH - group showed rCBV decreases at 2 h in the right inferior prefrontal region and anterior cingulate in response to alprazolam relative to placebo. FH + subjects reported more mood enhancement with alprazolam. This fMRI technique detected global and regional CBV changes induced by alprazolam. The location and rate of alprazolam-induced rCBV changes differed between FH + and FH - subjects. These changes may be related to the increased mood enhancement found in subjects genetically predisposed to alcoholism.Psychiatry Research 06/1998; 82(2):69-82. · 2.52 Impact Factor
