A good article covering ancient skepticism -- There were two distinct traditions or movements of skeptical thought: Pyrrhonian and Academic.
While ideas that can loosely be called skeptical may be found from very early in Greek philosophy, skepticism as an organized method of thinking in Greco-Roman antiquity appears in the post-Aristotelian period. There are two distinct traditions or movements of skeptical thought: Pyrrhonian and Academic. The hallmark of ancient Greco-Roman skepticism, in both traditions, is suspension of judgement, brought about by the juxtaposition of equally persuasive opposing views on any given question. In the Pyrrhonist version, but not the Academic, this is claimed to have a practical benefit: ataraxia or tranquility. In both traditions, however, skepticism is understood not merely as a topic of theoretical reflection, but as something to be lived. The Pyrrhonian tradition claimed inspiration from Pyrrho of Elis (c. 360–270 BCE), who is usually considered the first Greek skeptic. However, the exact nature of Pyrrho’s thinking is very hard to reconstruct, given the scarcity of the evidence. Pyrrho’s direct influence seems to have been short-lived. But shortly after Pyrrho another skeptical movement arose in the Academy, the school founded by Plato. The first head of the Academy to take the school in a skeptical direction was Arcesilaus of Pitane (316/5–241/0 BCE). Whether Pyrrho was an influence on him is a disputed question. But some aspects of Socrates’ activity, as Plato portrays him, might seem to encourage skepticism, and Arcesilaus is said to have acknowledged this influence. The skeptical Academy lasted for roughly two centuries, its other major figure being Carneades of Cyrene (214–129/8 BCE). By the early 1st century BCE the skepticism of the Academy seems to have moderated considerably, and it was at this point that the Academy itself, as an institution, came to an end. But in reaction to this softening of the skeptical attitude came a new skeptical movement led by Aenesidemus of Cnossos (dates uncertain, but active in the early first century BCE), repudiating the Academy and instead identifying itself with Pyrrho. This later Pyrrhonian movement continued for roughly three centuries. We know the names of a few Pyrrhonists. But the only complete Pyrrhonist works we have are the extensive surviving writings of Sextus Empiricus (probably late 2nd or early 3rd century CE). Because Oxford Bibliographies for Pyrrho of Elis and The Academy already exist, this bibliography is somewhat weighted toward the later Pyrrhonist tradition stemming from Aenesidemus.
It says: "In both traditions, however, skepticism is understood not merely as a topic of theoretical reflection, but as something to be lived."
And this is what would be different from Epicureanism -- as it seems that theoretical reflection is at times contained within Epicureanism?