Sulla had a hot temper, also a sign of lead damage (one of the Valentinian emperors is supposed to be a classic case, with terrific mood swings like Hitler's, that actually interfered with his ability to discharge his office), and he died in 78 B.C. when he suffered a stroke while indulging an outburst of anger at a pedlar.
His basic problem, very interestingly for your choice of handles, was something well out of his hands, and which has rough parallels with today. The society he inherited was concentrating financial resources in fewer hands, and a great deal of wealth was being plowed back into real estate, transforming the countryside from a productive breadbasket teeming with yeoman farmers (smallholders typically worked a couple of acres for subsistence) to a more productive agribusiness landscape dedicated to cash crops and agricultural "factories" peopled with hired hands and villani (slaves), which is what the old farms gradually became -- the ones that survived, around which the other holdings were consolidated. By the time of the Severi, Italy and Sicily were very much given over to wide olive and wine plantations (latifundia; the Spanish also used the term in the New World to refer to land-grant plantations and their owners). All this concentration, beginning in the time of the Gracchi and already at crisis levels by the time Sulla came of age, was driving hordes of freeholders off the land: their sons into the legions, and the fathers into the cities, to become the Roman Mob. And they weren't about to solve their social problem, because the engine of their social stresses was a money machine in the hands of the upper classes of Roman society, whose maintenance of ancient power and precedence Sulla championed against the adventurism of dispossessed nobles acting with and through the Plebs and its mob politics.
Interesting discussion of my name sake, but badly off-topic. I do not place a lot of weight on mental or physical diagnoses of historical figures though, but we might discuss this on a Roman history thread sometime!
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It could have been in the lead in the alloys that were used in the dishes and other eating utinsles oat the time. It used to be thought tomatoes were poinsonous. It turn out the tomatoes caused sickness because the acid in them extracted the lead in pewter and other alloys, causing them to get in the food and cause sickness.