Provided is a pharmaceutical composition for prevention and treatment of drug or alcohol addiction or bipolar disorder, comprising sodium phenylbutyrate (PBA). The pharmaceutical composition for prevention and treatment of drug or alcohol addiction or bipolar disorder in accordance with the present invention provides effects capable of inhibiting increases in locomotor activity which is a behavioral indicator of drug or alcohol addiction or bipolar disorder, by controlling a level of a neurotransmitter via regulation of expression of a neurotransmitter transporter.