I've just started reading Boswell's "Life of Johnson" and I fear that I in my 23rd year am going through a rather similar change as that which Johnson went through in his 20th. I let Boswell explain:
While he was at Lichfield, in the college vacation of the year 1729, he felt himself overwhelmed with an horrible hypochondria, with perpetual irritation, fretfulness, and impatience; and with a dejection, gloom, and despair, which made existence misery. From this dimal malady he never afterwards was perfectly relieved; and all his labours, and all his enjoyments, were but temporary interruptions of its baleful influence.
Indeed, I am currently in such a state of misery that I hope and pray to God that my affliction is like that of Johnson's and that my hypochondria is no more founded than that of Johnson's. For I do not think Johnson's hypochondria completely unfounded, for any misery as great as this must have a cause, but that perhaps the cause is, as Boswell later posits, "in some degree, occasioned by a defect in his nervous system, that inexplicable part of our frame."
Indeed, I hope my hypochondria is unfounded, and that my misery is a mental defect. And I pray that it leads not to madness. But it is a pity, too, that I should have the same misery as Johnson but none of the wit.
Anyway, at least to be sure, I will return to the physicians. Maybe I'll have a neurological work-up. And maybe something will come of it, some sort of knowledge as to the origins of my misery.