The Stoics likened life to a party, and determined there were five reasons to rationally exit the party (suicide):
1. In service of one's country, i.e., an old friend shows up to the party and requires your services.
2. The arrival of rowdy revelers, i.e., tyrants who force us against our will to say or do disgraceful things at the party.
3. Protracted illness that prevents the soul from the use of its tool, the body, i.e., spoilage of provisions for the party.
4. Poverty, i.e., scarceness of party provisions.
5. Madness, i.e., drunkenness at the party. In Buddhist terms, intoxicants lower one's inhibitions against doing no harm to others and, by default, to the self. In Stoic terms, this equates to lowering the inhibitions put in place by practicing virtue. According to Epictetus, the purpose of practicing virtue is for life to flow more smoothly, and as social animals, virtues directly impact our interactions with others. This agrees with the purpose of the Five Precepts of Buddhism, considered gifts to others for the good of social order (no killing, no stealing, no lying, no sexual misconduct, no intoxicants).
Source: Griffin, Miriam. "Philosophy, Cato, and Roman Suicide I," Greece and Rome, vol. 33, no. 1, 1986, pp. 64-77. Original source cited by Griffin, Stoicorum Veterum Fragmenta, a 1903-1905 collection by Hans von Arnim of fragments and testimony of the earlier Stoics. The Buddhist/Stoic commentary under madness is mine.
The source article and article II by Griffin are available for free online viewing at JSTOR.