Confounding Control in a Nonexperimental Study of STAR*D Data: Logistic Regression Balanced Covariates Better Than Boosted CART.
Confounding control in a nonexperimental study of STAR*D data: logistic regression balanced covariates better than boosted CART.
Filed under: Depression Treatment
Ann Epidemiol. 2013 Feb 15;
Ellis AR, Dusetzina SB, Hansen RA, Gaynes BN, Farley JF, Stürmer T
PURPOSE: Propensity scores (PSs), a powerful bias-reduction tool, can balance treatment groups on measured covariates in nonexperimental studies. We demonstrate the use of multiple PS estimation methods to optimize covariate balance. METHODS: We used secondary data from 1292 adults with nonpsychotic major depressive disorder in the Sequenced Treatment Alternatives to Relieve Depression trial (2001-2004). After initial citalopram treatment failed, patient preference influenced assignment to medication augmentation (n = 565) or switch (n = 727). To reduce selection bias, we used boosted classification and regression trees (BCART) and logistic regression iteratively to identify two potentially optimal PSs. We assessed and compared covariate balance. RESULTS: After iterative selection of interaction terms to minimize imbalance, logistic regression yielded better balance than BCART (average standardized absolute mean difference across 47 covariates: 0.03 vs. 0.08, matching; 0.02 vs. 0.05, weighting). CONCLUSIONS: Comparing multiple PS estimates is a pragmatic way to optimize balance. Logistic regression remains valuable for this purpose. Simulation studies are needed to compare PS models under varying conditions. Such studies should consider more flexible estimation methods, such as logistic models with automated selection of interactions or hybrid models using main effects logistic regression instead of a constant log-odds as the initial model for BCART.
HubMed – depression
The ?2 nicotinic acetylcholine receptor subunit differentially influences ethanol behavioral effects in the mouse.
Filed under: Depression Treatment
Alcohol. 2013 Mar; 47(2): 85-94
Dawson A, Miles MF, Damaj MI
The high co-morbidity between alcohol (ethanol) and nicotine abuse suggests that nicotinic acetylcholine receptors (nAChRs), thought to underlie nicotine dependence, may also be involved in alcohol dependence. The ?2* nAChR subtype serves as a potential interface for these interactions since they are the principle mediators of nicotine dependence and have recently been shown to modulate some acute responses to ethanol. Therefore, the aim of this study was to more fully characterize the role of ?2* nAChRs in ethanol-responsive behaviors in mice after acute exposure to the drug. We conducted a battery of tests in mice lacking the ?2* coding gene (Chrnb2) or pretreated with a selective ?2* nAChR antagonist for a range of ethanol-induced behaviors including locomotor depression, hypothermia, hypnosis, and anxiolysis. We also tested the effect of deletion on voluntary escalated ethanol consumption in an intermittent access two-bottle choice paradigm to determine the extent of these effects on drinking behavior. Our results showed that antagonism of ?2* nAChRs modulated some acute behaviors, namely by reducing recovery time from hypnosis and enhancing the anxiolytic-like response produced by acute ethanol in mice. Chrnb2 deletion had no effect on ethanol drinking behavior, however. We provide further evidence that ?2* nAChRs have a measurable role in mediating specific behavioral effects induced by acute ethanol exposure without affecting drinking behavior directly. We conclude that these receptors, along with being key components in nicotine dependence, may also present viable candidates in the discovery of the molecular underpinnings of alcohol dependence.
HubMed – depression
Long-Term Success of GUT-Directed Group Hypnosis for Patients With Refractory Irritable Bowel Syndrome: A Randomized Controlled Trial.
Filed under: Depression Treatment
Am J Gastroenterol. 2013 Feb 19;
Moser G, Trägner S, Gajowniczek EE, Mikulits A, Michalski M, Kazemi-Shirazi L, Kulnigg-Dabsch S, Führer M, Ponocny-Seliger E, Dejaco C, Miehsler W
OBJECTIVES:Gut-directed hypnotherapy (GHT) in individual sessions is highly effective in the treatment of irritable bowel syndrome (IBS). This study aimed to assess the long-term effect of GHT in group sessions for refractory IBS.METHODS:A total of 164 patients with IBS (Rome-III-criteria) were screened, and 100 refractory to usual treatment were randomized 1:1 either to supportive talks with medical treatment (SMT) or to SMT with GHT (10 weekly sessions within 12 weeks). The primary end point was a clinically important improvement on several dimensions of daily life (assessed by IBS impact scale) after treatment and 12-month follow-up. The secondary end point was improvement in general quality of life (QOL; Medical Outcome Study Short-Form-36), psychological status (Hospital Anxiety Depression Scale) and reduction of single IBS symptoms. Analysis was by intention to treat.RESULTS:A total of 90 patients received allocated intervention. After treatment, 28 (60.8%) out of 46 GHT patients and 18 (40.9%) out of 44 SMTs improved (absolute difference 20.0%; 95% confidence interval (CI): 0-40.2%; P=0.046); over 15 months, 54.3% of GHT patients and 25.0% of controls improved (absolute difference 29.4%; 95% CI 10.1-48.6%; P=0.004). GHT with SMT improved physical and psychological well being significantly more than SMT alone (P<0.001). Gender, age, disease duration and IBS type did not have an influence on the long-term success of GHT.CONCLUSIONS:GHT improves IBS-related QOL, is superior to SMT alone, and shows a long-term effect even in refractory IBS.Am J Gastroenterol advance online publication, 19 February 2013; doi:10.1038/ajg.2013.19. HubMed – depression
Find More Depression Treatment Information…