I have a few ideas about the "When should you tell?" issue that I wanted to put on the table for discussion. There can be no hard fast rule regarding "Should you tell?" It depends on who you are dealing with. Some managers are totally bottom line oriented and some have a significant concern for people. I would suggest unless you are quite certain that you will get a humane reception both to your face and when you leave the room- hold back until you think your symptoms are quite obvious or performance is being compromised by the PD. First try to sit down with someone you can be honest with (a spouse, adult child, friend etc.) and honestly assess how your PD is affecting you in the workplace. Then put yourself in a good manager's shoes and ask yourself- How is PD affecting my employees' (your) work and the mission (i.e. profitability) of my organization? If so what are the best steps to take both for the organization and the employee's welfare? What adaptations to the job description and/or the work environment can be made or if not what is the most humane way to ease him/her into disability or early retirement? Then- at the right time act preemptively. Explain the diagnosis prognosis as well as your needs and desires. Explain your understanding of the impact on the organization and then suggest possible remedies. Remember, at least in the US your employer MUST make reasonable accommodation to your handicap and cannot fire you because of a handicap. Also according to the ADA a perspective employer cannot ask about health status during the hiring process. He/she can only ask after you have been hired for the purpose of making accommodations.