drinking. A 2002 US study by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) showed that 17.7% of individuals diagnosed as alcohol dependent more than one year prior returned to low-risk drinking. This group, however, showed fewer initial symptoms of dependency. A follow-up study, using the same subjects that were judged to be in remission in 2001–2002, examined the rates of return to problem drinking in 2004–2005. The study found abstinence from alcohol was the most stable form of remission for recovering alcoholics. There was also a 1973 study showing chronic alcoholics drinking moderately again, but a 1982 follow-up showed that 95% of subjects were not able to maintain drinking in moderation over the long term. Another study was a long-term (60 year) follow-up of two groups of alcoholic men which concluded that "return to controlled drinking rarely persisted for much more than a decade without relapse or evolution into abstinence." Internet based measures appear to be useful at least in the short term. Medications In the United States there are four approved medications for alcoholism: acamprosate, two methods of using naltrexone and disulfiram. Acamprosate may stabilise the brain chemistry that is altered due to alcohol dependence via antagonising the actions of glutamate, a neurotransmitter which is hyperactive in the post-withdrawal phase. By reducing excessive NMDA activity which occurs at the onset of alcohol withdrawal, acamprosate can reduce or prevent alcohol withdrawal related neurotoxicity. Acamprosate reduces the risk of relapse amongst alcohol-dependent persons. Naltrexone is a competitive antagonist for opioid receptors, effectively blocking the effects of endorphins and opioids. Naltrexone is used to decrease cravings for alcohol and encourage abstinence. Alcohol causes the body to release endorphins, which in turn release dopamine and activate the reward pathways; hence in the body Naltrexone reduces the pleasurable effects from consuming alcohol. Evidence supports a reduced risk of relapse among alcohol-dependent persons and a decrease in excessive drinking. Nalmefene also appears effective and works in a similar manner. Disulfiram prevents the elimination of acetaldehyde, a chemical the body produces when breaking down ethanol. Acetaldehyde itself is the cause of many hangover symptoms from alcohol use. The overall effect is discomfort when alcohol is ingested: an extremely fast-acting and long-lasting, uncomfortable hangover. Several other drugs are also used and many are under investigation. Benzodiazepines, while useful in the management of acute alcohol withdrawal, if used long-term can cause a worse outcome in alcoholism.