The present invention provides a medicament having a wider treatment spectrum, causing a fewer side effects and superior in tolerability and safety, as compared to known typical antipsychotic agents and atypical antipsychotic agents. The present invention related to a medicament containing (I) a compound which is 7-[4-(4-benzo[b]thiophen-4-yl-piperazin-l-yl)butoxy]- lHquinolin- 2-one or a salt thereof, and (II) at least one drug selected from the group consisting of a mood stabilizer, a serotonin re-uptake inhibitor, a norepinephrine reuptake inhibitor, a serotonin and norepinephrine reuptake inhibitor, a noradrenergic and specific serotonergic antidepressant, an antianxiety drug, a tricyclic antidepressant, a tetracyclic antidepressant, an antipsychotic drug and an anti-ADHD drug, in combination.
