The present invention relates to a pharmaceutical composition for treating, for example, a disorder or condition selected from the group consisting of hypertension, depression, generalized anxiety disorder, phobias, posttraumatic stress disorder, avoidant personality disorder, sexual dysfunction, eating disorders, obesity, chemical dependencies, cluster headache, migraine, pain, Alzheimer's disease, obsessive-compulsive disorder, panic disorder, memory disorders, Parkinson's diseases, endocrine disorders, cerebellar ataxia, gastrointestinal tract disorders, negative symptoms of schizophrenia, premenstrual syndrome, Fibromyalgia Syndrome, stress incontinence, Tourette syndrome, trichotillomania, kleptomania, male impotence, cancer, chronic paroxysmal hemicrania and headache in a mammal, preferably a human, comprising (i) an atypical antipsychotic or a pharmaceutically acceptable salt thereof, (ii) a 5-HT.sub.1B receptor antagonist or a pharmaceutically acceptable salt thereof, wherein the 5-HT.sub.1B receptor antagonist is selected from the group consisting of (A) a compound of the formula I as described in the specification and (B) a compound of the formula II as described in the specification, and optionally (iii) a pharmaceutically acceptable carrier.