Is Hamlet insane?
Ah, one of the great questions about one of the great dramas in history.
Is Hamlet, the titular (anti)hero of Hamlet, mentally ill? Ravaged with grief? Acting out due to unexpressed rage? Simply depressed and having an existential crisis (which ends quite poorly as far as those crises go)? This is an excellent question, and true to Shakespearean form, its answer is elusive. Or, more accurately, its answer is heavily subjective.
As with all great art, every single person who reads Hamlet will experience it differently. The reader's purpose, their life experiences, their preconceived notions of the material or the author - so much comes into play. What makes this question about Hamlet so interesting is that one could conceivably make an argument for any, if not all, of the above-listed potential maladies. Indeed, there are undoubtedly countless other explanations for which one could mount a well-evidenced claim.
I think this is the right time for the follow-up questions: Does it matter if Hamlet is "insane"? Does it matter if he has an unhealthy obsession with his mother? Does it matter if he is simply a spoiled college boy who's touchy about things at home? If he is simply marooned in desperation and grief after losing his father? If he is actually seeing the ghost or simply suggestible due to the claims of others and his desire to see his father again? If his impulsiveness springs from an uncontrolled emotional crisis or simply from the ardor of youth? If his obsession with death is situational or a sign of a much darker, more permanent side of his personality which was only waiting for the right moment to explode?
Shakespeare does not give us the answers, and that is half the fun. Hamlet is an astonishingly strange character who beguiles and frustrates readers centuries after his creator committed him to paper. One of the strange and gorgeous things about Hamlet is how quickly he swings from being hilarious, catty, gleeful, and even likable to vicious, cruel, manipulative, and morbidly depressed - a cipher, and a frightening, truly dangerous one.I encourage all readers of this great work of drama to avoid looking for definitive answers.
Enjoy the existential roller-coaster!