Pegasos and Dignitas in Switzerland are accepting application from mentally ill people.
But, the entire process is not easy, takes longer and costs more.
Pegasos: You have to travel to Switzerland for a independent opinion of a Swiss psychiatrist. The psychiatrist has to confirm, that you are judgemental. This costs additional CHF1.000,- + travel expenses. But there is no guarantee that your application will be approved.
Dignitas: A lot more paperwork and the opinion of an independent psychiatrist is required. Processing takes at least 1 year and the chance that the application will be approved is very low.
If you also have a physical illness or no illness at all but a certain age (40 or older), send me a PM and I might have an idea.
There are other options in the Netherlands, Belgium, Sweden and Canada. But you have to be resident of those countries.