Schematic representation of JPZDD effects on 5-HT system. JPZDD exerts an anti-tic and anti-anxiety effect on the 5-HT system in a rat model of Tourette syndrome (TS) and comorbid anxiety mainly by inhibiting the expression of 5-HT2C mRNA in the striatum, improved the relative deficiency of 5-HT, and further enhanced the excitability of 5-HT system. 5-HT, serotonin; 5-HT2CR, 5-HT type 2C receptor; JPZDD, Jian-pi-zhi-dong decoction.