Back in Archaic times, on the island of Keos, it was the custom for men when they turned 60 to kill themselves by drinking hemlock!
This appears to have been a novel means of population control. It was known as the Kean Law.
Here's a quote from Strabo:
It is reputed that there was once a law among the Keans, which appears to have ordered those who were over sixty years of age to drink hemlock, in order that the food might be sufficient for the rest. The law is mentioned by Menander, who wrote, “The law of the Keans is good, that he who is unable to live well should not live wretchedly.”This comes from Strabo's Geography, section 10.5.6. I've quoted the Perseus edition, and reworked it a little to make it more readable.
Just how stressed and hungry does a population have to be, for something like this to become a custom?
This sort of ugliness inevitably devalues life in general. At some point which can't be dated, Athens invaded Keos. The locals were besieged and, not surprisingly, quickly ran out of food. Here's Strabo again on what happened next:
And it is said that once, when they were being besieged by the Athenians, the Keans voted, setting a definite age, that the oldest among them should be put to death, but the Athenians raised the siege.The brilliant historical writer Mary Renault mentions this charming custom in The Praise Singer, which is about the life of the great poet Simonides. Simonides was born on Keos. Renault has the father of Simonides suffer a stroke. The father demands the cup of hemlock from his son.
The actual suicide appears to have been carried out at a community festival. The man to die would gird his head in flowers and, presumably, parade and say his farewells, before taking a cup of hemlock. (Hemlock grows naturally on Keos to this day.)
There's a fair chance that if this happened on Keos, then it occurred on other islands too. The law probably didn't need to apply to women, by the way, because the chances of a woman living to 60 were approximately zero. If somewhow a lady survived that long, I imagine the rule applied.
Things did improve. By Classical times compulsory suicide had disappeared everywhere. In fact in some places it came to be considered reprehensible. In Classical Athens a suicide was considered guilty of a crime against the state, because the dead man had deprived the state of a useful citizen. The dead citizen was "punished" by having his hand cut off and buried seperately. Plato has Socrates say at one point that a suicide is like a soldier deserting his post.
So, imagine you were a man on Keos, and 59 years old.