<unk> s <unk> D,<unk> ,<unk> s), sometimes called "benzos", are a class of psychoactive drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. As depressants—drugs which lower brain activity—they are prescribed to treat conditions such as anxiety, insomnia, and seizures. The first<unk> , chlordiazepoxide (Librium), was discovered accidentally by Leo Sternbach in 1955 and was made available in 1960 by Hoffmann–La Roche, which soon followed with diazepam (Valium) in 1963. By 1977,<unk> s were the most prescribed medications globally; the introduction of selective serotonin reuptake inhibitors (SSRIs), among other factors, decreased rates of prescription, but they remain frequently used worldwide.<unk> s are depressants that enhance the effect of the neurotransmitter gamma-aminobutyric acid (GABA) at the GABAA receptor, resulting in sedative, hypnotic (sleep-inducing), anxiolytic (anti-anxiety), anticonvulsant, and muscle relaxant properties. High doses of many shorter-acting<unk> s may also cause anterograde amnesia and dissociation. These properties make<unk> s useful in treating anxiety, panic disorder, insomnia, agitation, seizures, muscle spasms, alcohol withdrawal and as a premedication for medical or dental procedures.<unk> s are categorized as short, intermediate, or long-acting. Short- and intermediate-acting<unk> s are preferred for the treatment of insomnia; longer-acting<unk> s are recommended for the treatment of anxiety.<unk> s are generally viewed as safe and effective for short-term use—about two to four weeks—although cognitive impairment and paradoxical effects such as aggression or behavioral disinhibition can occur. A minority of people have reactions such as worsened agitation or panic when they stop taking<unk> s.<unk> s are associated with an increased risk of suicide due to aggression, impulsivity, and negative withdrawal effects. Long-term use is controversial because of concerns about decreasing effectiveness, physical dependence,<unk>  withdrawal syndrome, and an increased risk of dementia and cancer. In the long term, stopping<unk> s often leads to improved physical and mental health. The elderly are at an increased risk of both short- and long-term adverse effects, and as a result, all<unk> s are listed in the Beers List of inappropriate medications for older adults. There is controversy concerning the safety of<unk> s in pregnancy. While they are not major teratogens, uncertainty remains as to whether they cause cleft palate in a small number of babies and whether neurobehavioural effects occur as a result of prenatal exposure; they are known to cause withdrawal symptoms in the newborn. Taken in overdose,<unk> s can cause dangerous deep unconsciousness, but they are less toxic than their predecessors, the barbiturates, and death rarely results when a<unk>  is the only drug taken. Combined with other central nervous system (CNS) depressants such as alcohol and opioids, the potential for toxicity and fatal overdose increases significantly.<unk> s are commonly misused and taken in combination with other addictive substances.
Benzodiazepine
Synthetic cannabinoids
Antidepressant
Alcohol 
Gabapentinoid
Substituted amphetamine
Methamphetamine
Antipsychotic