Trazodone hydrochloride is an anti-anxiety and depression medication that has the effect of improving sleep without dependence. Depression and anxiety are related to a disorder of a neurotransmitter called 5-hydroxytryptamine in the brain, and the pharmacological mechanism of trazodone is to correct this disorder and increase the concentration of 5-hydroxytryptamine. Therefore, the drug is often taken for a longer period of time in order to allow the concentration of the substance in the brain to reach equilibrium. The overall course of treatment for depression or anxiety disorders is also on the long side, so the duration of drug treatment can be on the long side.