You are reporting that your employee's performance is acceptable and that you have no concerns after so many years. You should monitor his performance as you always have, and if problems return, engage PAS and follow the supervisor referral process recommended to you. There is no other action for you to take unless there is an active contract with Employee Occupational Health and Wellness (EOHW). If so, it would be appropriate to inform EOHW. Performance and ability to perform the position's essential functions are the dominant concerns of the employer. His potential relapse would be his personal medical concern for the moment. It is possible that the relapse will not affect his performance again, or problems could return. Your vigilance as a supervisor will help you intervene early if needed to provide support.