Disclosed are methods for treating a psychiatric disease or disorder and/or symptoms thereof in a subject in need thereof, the method comprising administering to the subject an effective amount of an antagonist of the Na+-K+-2Cl— cation-chloride cotransporter isoform 1 (NKCC1) for treating the psychiatric disorder and/or the symptoms thereof in the subject. The methods further may include administering to the subject a dopamine D1 agonist and/or a GABAA agonist, optionally at a subeffective dose, where co-administering the antagonist of NKCC1 improves the efficacy of the dopamine D1 agonist and/or the GABAA agonist, optionally at the subeffective dose, for treating the psychiatric disease or disorder and/or symptoms thereof.