A La Jolla psychiatrist has been accused by the state Board of Medical Quality Assurance of three more instances of incompetence and negligence because of alleged sexual misconduct with women who went to him for psychiatric help. Instead of helping them, the charges say, Dr. Stuart L. Brown concentrated during therapy sessions on talking about his personal problems, expressing his attraction for the women and kissing, hugging and fondling them. The BMQA, which regulates psychiatrists and other physicians, charges in the complaint that Brown's conduct constituted incompetence and gross negligence and that his license to practice medicine should be revoked. A similar complaint was filed against Brown in July. In one case, the doctor had sexual intercourse with a patient four times at various locations, the complaint says.