The invention relates to an injectable depot formulation, comprising: a biocompatible polymer; an organic solvent combined with the biocompatible polymer to form a viscous gel; and a small molecule drug incorporated in the viscous gel. More specifically risperidone is disclosed with polyactide polymer or a copolymer based on lactic acid and glycolic acid together with benzyl alcohol, benzyl benzoate, ethyl benzoate, ethanol, triacetin or N-methyl-2-pyrrolidone for psychotherapeutic treatments.