Sources tell People magazine that a bad breakup may have caused Alexa Ray Joel's breakdown, which led to her hospitalization Saturday. The singer-songwriter reportedly took Traumeel, a homeopathic medication, and then experienced difficulty breathing. Sources say she was "distraught over an argument with her boyfriend." Joel has been public about her struggles with dating and relationships, venting on her MySpace page and telling People last year that she can "get very dark." Joel has been released from the hospital and is with her father, Billy Joel. Her mother is model Christie Brinkley.