Martha C. Nussbaum argues in The Therapy of Desire: Theory and Practice in Hellenistic Ethics that all three major Hellenistic schools (Epicureanism, Stoicism, Skeptics) shared a practical, therapeutic (as opposed to e.g. theoretic, metaphysical) focus:
Philosophy heals human diseases, diseases produced by false beliefs. Its arguments are to the soul as the doctor's remedies are to the body. They can heal, and they are to be evaluated in terms of their power to heal […] This general picture of philosophy's task is common to all three major Hellenistic schools, at both Greece and Rome.
She includes a relevant quote from Epicurus:
Empty is that philosopher's argument by which no human suffering is therapeutically treated. For just as there is no use in a medical art that does not cast out the sickness of bodies, so too there is no use in philosophy, unless it casts out the suffering of the soul.
I am wondering whether this focus is conventionally observed in the history of philosophy and whether it is indeed specific to the Hellenistic schools, or whether Nussbaum presents some kind of minority opinion.
UPDATE Philosophy as "therapy" is also discussed here (as pointed out here) in relation to 20th-century philosophy and an understanding of Wittgenstein as inspiring to "help us work ourselves out of confusions we become entangled in when philosophizing".