alcohol

Alcohol, sometimes referred to by the chemical name ethanol, is a depressant drug that is the active ingredient in fermented drinks such as beer, wine, and distilled spirits (hard liquor). It is one of the oldest and most commonly consumed recreational drugs, causing the characteristic effects of alcohol intoxication ("drunkenness"). Among other effects, alcohol produces happiness and euphoria, decreased anxiety, increased sociability, sedation, impairment of cognitive, memory, motor, and sensory function, and generalized depression of central nervous system (CNS) function. Ethanol is only one of several types of alcohol; other alcohols such as methanol and isopropyl alcohol are significantly more toxic. A mild, brief exposure to isopropyl alcohol (which is only moderately more toxic than ethanol) is unlikely to cause any serious harm, but methanol is lethal even in small quantities, as little as 10–15 milliliters (2–3 teaspoons). However, several analogues that naturally occur as psychoactive alcohols in alcoholic drinks are less toxic than ethanol. Unlike primary alcohols like ethanol, tertiary alcohols cannot be oxidized into aldehyde or carboxylic acid metabolites, which are often toxic. For example, the tertiary alcohol 2M2B is 20 times more potent than ethanol, and has been used recreationally. Alcohol has a variety of short-term and long-term adverse effects. Short-term adverse effects include generalized impairment of neurocognitive function, dizziness, nausea, vomiting, and hangover-like symptoms. Alcohol is addictive to humans, and can result in alcohol use disorder, dependence and withdrawal. It can have a variety of long-term adverse effects on health, such as liver and brain damage, and its consumption can cause cancer. The adverse effects of alcohol on health are most important when it is used in excessive quantities or with heavy frequency. However, some of them, such as increased risk of certain cancers, may occur even with light or moderate alcohol consumption. In high amounts, alcohol may cause loss of consciousness or, in severe cases, death. Alcohol works in the brain primarily by increasing the effects of γ-Aminobutyric acid (GABA), the major inhibitory neurotransmitter in the brain; by facilitating GABA's actions, alcohol suppresses the activity of the CNS. The substance also directly affects a number of other neurotransmitter systems including those of glutamate, glycine, acetylcholine, and serotonin.