<unk> s (abbreviation<unk>  are a class of<unk>  drugs first used in the 1950s. They are named after the drugs' molecular structure, which contains three rings of atoms (compare tetracyclic<unk> .
Tricyclic antidepressant
Typical antipsychotic
Mood stabilizer
Selective serotonin reuptake inhibitor
Acetylcholinesterase inhibitor
Antidepressants
Depressant
Atypical antipsychotics