Based on your knowledge, identify the disorder an individual is experiencing; what are the symptoms corresponding to the disorder; provide a treatment that is most benefit to the person in the case study.

Mark, age 33, was taken by his wife to the hospital emergency room late one night after he climbed onto the roof of the family house, declared himself "the happiest man in the world," and refused to come down for hours. The doctors at the E. R. gave Mark medications to help calm him and arranged for Mark to have a full psychiatric evaluation. A few days later, Mark and his wife met with a psychiatrist. They reported that he often experienced periods when he was extremely excited, talked very quickly, and slept very little. Mark was accustomed to his strange moods, but his wife admitted to the psychiatrist that she had been worrying about their finances since Mark started using credit cards to buy expensive and unnecessary electronic equipment when he was in an excited mood. Six months prior, Mark had come home with two digital video players, three large screen televisions, and a $5000 sound system with the plan of transforming the family basement into the ''ultimate entertainment center.” Mark stayed in the basement for several days setting up his new system but then suddenly abandoned the project. Mark's wife also explained that he experienced periods when he was extremely ''mellow and sad" even to the point of not getting out of bed for days at a time. Mark recalled feeling periodically depressed since he was in college, but he told the psychiatrist that his "down times" seemed to be lasting longer and feeling more intense as he got older. Mark's wife added that she felt like there were "three Marks: excited Mark, sad Mark, and regular Mark."