Tranquilizers are drugs that calm anxiety and help sleep by acting on the central nervous system. They are often called depressants because they suppress the CNS and slow the body down. Tranquilizers are used to treat mental illnesses involving psychoses, which cause disturbances in perception, thought, and emotion. Minor tranquilizers treat anxiety while major tranquilizers treat psychoses like schizophrenia. Antipsychotic drugs target the dopamine system, which is implicated in psychosis symptoms. First and second generation antipsychotics differ in their structures and side effect profiles.