Depressants

Depressants are a class of psychoactive substances that slow activity in the central nervous system. They reduce arousal, ease anxiety, impair coordination and reflexes, and can induce sleep. Depressants occur in many forms, from commonly consumed everyday substances to prescription medicines and illicit drugs. Examples frequently cited include alcohol; benzodiazepines such as diazepam and temazepam; barbiturates; non-benzodiazepine sedative-hypnotics such as zolpidem; and opioids such as morphine or heroin.

Most depressants enhance the activity of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), or otherwise dampen excitatory signaling. Opioids act on opioid receptors to dampen pain and respiration, while anesthetics and some sedatives reduce neural activity through various targets. The net effect is slower brain activity, reduced alertness, and suppressed breathing at higher doses.

Short-term effects include drowsiness, slowed speech, impaired judgment, and slowed breathing. At higher doses they can cause loss of consciousness or coma. Long-term use can lead to tolerance, dependence, and withdrawal symptoms. Mixing depressants with each other or with alcohol markedly increases risks, including respiratory depression and overdose.

Depressants have legitimate medical roles: benzodiazepines and other sedatives are prescribed for anxiety and sleep disorders; opioids for pain under medical supervision; some anesthetics for surgery. Because of abuse potential, many are regulated, prescribed in controlled amounts, and monitored for safety.

Prevention and treatment emphasize safer use, education, and access to treatment for dependence. Dependence may require medical detoxification, behavioral therapies, and, for some substances, pharmacotherapies such as methadone or buprenorphine for opioid use disorder or relapse prevention. Early intervention reduces the risk of overdose and injury.