Alcohol is a hydroxyl compound, where the hydroxyl functional group remains attached to a carbon atom. Alcoholic beverages contain ethanol or ethyl alcohol. These beverages are basically a fermentation product of fruits, vegetables, or certain grains like barley, rice, corn, rye, etc. Fermentation is the process where bacteria or yeast is used to convert the sugars found in these foods to alcohol. Today, alcohol is one of the most popular beverages and also a psychoactive drug that produces a depressant effect on the brain or central nervous system. This is why it is classified as a central nervous system depressant. Let's find out more about depressants and what makes alcohol a depressant, along with the effects of alcohol on human brain and body. A depressant is a psychoactive drug that can affect mood and perception, by acting on the central nervous system (CNS). It is a substance that slows down or inhibits the functions of the central nervous system, which in turn relaxes the body and mind. In other words, depressants are drugs that produce a depressant effect on the central nervous system, and they do this either by inhibiting the brain's ability to produce stimulating chemicals, or by imitating the chemicals that produce a sedative effect. Depressants are used in several medical problems, including anxiety, epilepsy, and sleep disorders. But often, such substances are abused for their intoxicating effect by a large number of people across the world. Alcohol is considered a depressant as it slows down the activity of the central nervous system. It alters perception by blocking the transmission of messages from the nerve receptors to the brain. This can affect cognitive abilities, judgment, movement, and senses of an individual. Alcohol can also affect the brain chemistry, mainly by changing the levels of both 'excitatory' and 'inhibitory' neurotransmitters. Neurotransmitters are the chemicals that transmit nerve impulses between the brain and rest of the body. As mentioned already, alcohol acts on the brain or central nervous system by altering the levels of neurotransmitters. It has been observed that low to moderate doses of alcohol can activate the GABA (gamma-aminobutyric acid) receptors, which in turn can slow down the transmission of messages between the brain and rest of the body. This can manifest in sedation, relaxation and relief from anxiety, and lowered social inhibition. In addition to activating the inhibitory GABA receptors, alcohol suppresses the activity of excitatory neurotransmitters, like glutamate. Glutamate is mainly responsible for increasing the activity of the brain. So, when alcohol suppresses the release of this neurotransmitter, the activities of the brain are slowed down. The combined effects of an increase in inhibitory neurotransmitters, and a reduction in excitatory neurotransmitters eventually alter mood, perception, balance and coordination, reflexes, vision, and speech of an individual. ☛ In very small amounts, alcohol can reduce anxiety and make you feel more relaxed. But, overuse of alcohol produces a state of intoxication, which can manifest in slurred speech, loss of balance and coordination, confusion, disorientation, blurred vision, and slowed reaction time or slow reflexes. All these resemble the effects of other depressants like barbiturates, tranquilizers, and benzodiazepines. ☛ Like depressants, long-term alcohol abuse can cause addiction or alcoholism, and affects the vital organs like liver, kidney, and heart, besides creating relationship problems. Alcoholism is also associated with many psychiatric disorders, such as depression, anxiety, and personality disorders. ☛ Alcohol poisoning on the other hand, can take place if an individual consumes a very large amount of alcohol in a very short period of time. It can cause vomiting, slow and irregular breathing, stupor, unconsciousness, low blood sugar, and sometimes seizures and death. Sudden cessation of alcohol consumption after its prolonged use is likely to cause withdrawal symptoms like tremors, sleeping problems, anxiety, and convulsions. To sum up, alcohol is a central nervous system depressant, that can cause serious health problems if abused for a long time. As the effects of alcohol and other depressants like tranquilizers and benzodiazepines are the same, taking them simultaneously can cause respiratory depression (hypoventilation) and reduce heart rate to a dangerous level.