Suicide as a rational act

When I went to the doctor's, I was handed a questionnaire about my feelings and mood.  One of the items asked if I was depressed or had suicidal thoughts.  I realize that suicide during most times has been illegal, looked at as irrational, etc.  A government might treat a suicide as a sin as might a religion.  Life was provided by God and is too much of a gift to waste, etc., etc.  

I tend to more or less agree with such thinking but as I age, I can see that a person's body might deteriorate to a condition of too much pain and too little prospect of relief.  I have been told and I have read that some ancient societies had ways to apply for permission to commit suicide and avoid shame and various forms of social dishonor or estate penalty.