other reinforcing drugs. Drugs which help to re-stabilize the glutamate system such as N-acetylcysteine have been proposed for the treatment of addiction to cocaine, nicotine, and alcohol. The effect on depression and returning to drinking among individuals with alcohol dependence has always been controversial. Studies show that after doing a study on men and women hospitalized for alcohol dependence the likelihood of returning to drinking with depression is extremely high. A diagnosis of major depression at entry into an inpatient treatment for alcohol dependence showed shorter times to first drink and also relapse in both women and men. Digestive system and weight gain The impact of alcohol on weight-gain is contentious: some studies find no effect, others find decreased or increased effect on weight gain. Alcohol use increases the risk of chronic gastritis (stomach inflammation); it is one cause of cirrhosis, hepatitis, and pancreatitis in both its chronic and acute forms. Metabolic syndrome A national survey (NHANES) conducted in the U.S. concluded, "Mild to moderate alcohol consumption is associated with a lower prevalence of the metabolic syndrome, with a favorable influence on lipids, waist circumference, and fasting insulin. This association was strongest among whites and among beer and wine drinkers." Similarly, a national survey conducted in Korea reported a J-curve association between alcohol intake and metabolic syndrome: "The results of the present study suggest that the metabolic syndrome is negatively associated with light alcohol consumption (1–15 g alcohol/d) in Korean adults," but risk increased at higher alcohol consumption. Gallbladder effects Research has found that drinking reduces the risk of developing gallstones. Compared with alcohol abstainers, the relative risk of gallstone disease, controlling for age, sex, education, smoking, and body mass index, is 0.83 for occasional and regular moderate drinkers (< 25 ml of ethanol per day), 0.67 for intermediate drinkers (25-50 ml per day), and 0.58 for heavy drinkers. This inverse association was consistent across strata of age, sex, and body mass index." Frequency of drinking also appears to be a factor. "An increase in frequency of alcohol consumption also was related to decreased risk. Combining the reports of quantity and frequency of alcohol intake, a consumption pattern that reflected frequent intake (5–7 days/week) of any given amount of alcohol was associated with a decreased risk, as compared with nondrinkers. In contrast, infrequent alcohol intake (1–2 days/week) showed no significant association with risk." A large self-reported study published in 1998