<unk>  sometimes referred to by the chemical name ethanol, is a psychoactive drug that is the active ingredient in drinks such as beer, wine, and distilled spirits (hard liquor). It is one of the oldest and most common recreational substances, causing the characteristic effects of<unk> intoxication ("drunkenness"). Among other effects,<unk> produces happiness and euphoria, decreased anxiety, increased sociability, sedation, impairment of cognitive, memory, motor, and sensory function, and generalized depression of central nervous system function. Ethanol is only one of several types of<unk>  but it is the only type of<unk> that is found in<unk> c beverages or commonly used for recreational purposes; other<unk>  such as methanol and isopropyl<unk> are significantly more toxic. A mild, brief exposure to isopropanol, being only moderately more toxic than ethanol, is unlikely to cause any serious harm. Methanol, being profoundly more toxic than ethanol, is lethal in quantities as small as 10–15 milliliters (2–3 tsp).<unk> 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.<unk> is addictive to humans, and can result in<unk> use disorder, dependence and withdrawal. It can have a variety of long-term adverse effects on health, for instance liver damage, brain damage, and its consumption is the fifth leading cause of cancer. The adverse effects of<unk> 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<unk> consumption. In high amounts,<unk> may cause loss of consciousness or, in severe cases, death.<unk> works in the brain primarily by increasing the effects of a neurotransmitter called γ-aminobutyric acid, or GABA. This is the major inhibitory neurotransmitter in the brain, and by facilitating its actions,<unk> suppresses the activity of the central nervous system. The substance also directly affects a number of other neurotransmitter systems including those of glutamate, glycine, acetylcholine, and serotonin. The pleasurable effects of<unk> ingestion are the result of increased levels of dopamine and endogenous opioids in the reward pathways of the brain.<unk> also has toxic and unpleasant actions in the body, many of which are mediated by its byproduct acetaldehyde.<unk> has been produced and consumed by humans for its psychoactive effects for almost 10,000 years. Drinking<unk> is generally socially acceptable and is legal in most countries, unlike with many other recreational substances. However, there are often restrictions on<unk> sale and use, for instance a minimum age for drinking and laws against public drinking and drinking and driving.<unk> has considerable societal and cultural significance and has important social roles in much of the world. Drinking establishments, such as bars and nightclubs, revolve primarily around the sale and consumption of<unk> c beverages, and parties, festivals, and social gatherings commonly involve<unk> consumption.<unk> is unique in that it is the only drug that damages others more than the user. It is related to various societal problems, including drunk driving, accidental injuries, sexual assaults, domestic abuse, and violent crime.<unk> remains illegal for sale and consumption in a number of countries, mainly in the Middle East. While some religions, including Islam, prohibit<unk> consumption, other religions, such as Christianity and Shinto, utilize<unk> in sacrament and libation.
Alcohol 
Toxic alcohol
Benzyl alcohol
Tobacco
Cannabis
Cannabis 
Smokeless tobacco
Polychlorinated biphenyl