Is my husband bipolar? He has just up and left, leaving only a long letter, devoid of emotion and feeling.?

For the past four months or so, my husband has been doing odd, impulsive things - typically out-of-his-character. He shaved his head, scheduled himself to have Lasik eye surgery ($3,500) and didn't even discuss it with me first. He just graduated from law school and lied all summer long about looking for jobs and studying for the BAR exam. The week before the BAR, he came to me with an acceptance letter into a Master's of Social Work program and said me he was going back to school this fall. He said, "I don't want to be a lawyer, there is no money in law in our state. I can make up to $300,000 a year here, working as a licensed therapist." (They typically make around $35,000-40,000 in our state.) The next week he pretended to take the BAR exams for three days. I really thought he was taking them. The next weekend, I took a weekend trip, came home and he was gone. He had taken everything of his and left a long robotic-style letter. He said he didn't want to be married anymore.