Disclosed is a pharmaceutical composition comprising a compound represented by the formula (I)

or a pharmaceutically acceptable salt thereof as an active ingredient, which has an antagonistic activity on a melanin-concentrating hormone receptor. The pharmaceutical composition is useful, due to its antagonistic activity on a MCH receptor, for the prevention or treatment of a disease such as depression, anxiety disorders (e.g., generalized anxiety disorder, post traumatic stress disorder, panic disorder, obsessive-compulsive disorder, social anxiety disorder), attention deficit disorder, mania, manic-depressive disorder, schizophrenia, mood disorders, stress, sleep disorder, attacks, memory impairment, cognitive impairment, dementia, amnesia, delirium, obesity, eating disorder, appetite disorder, hyperphagia, bulimia, cibophobia, diabetes, a cardiovascular diseases, hypertension, dyslipidemia, cardiac infarction, movement disorder (e.g., Parkinson's disease, epilepsy, convulsion, tremor), drug abuse and drug addiction.