From his rapid-fire stand-up comedy riffs to his breakout role in Mork & Mindy and his Academy Award-winning performance in Good Will Hunting, Robin Williams was a singularly innovative and beloved entertainer. He often came across as a man possessed, holding forth on culture and politics while mixing in personal revelations — all with mercurial, tongue-twisting intensity as he inhabited and shed one character after another with lightning speed.

But as Dave Itzkoff shows in this revelatory biography, Williams’s comic brilliance masked a deep well of conflicting emotions and self-doubt, which he drew upon in his comedy and in celebrated films like Dead Poets Society; Good Morning, Vietnam; The Fisher King; Aladdin; and Mrs. Doubtfire, where he showcased his limitless gift for improvisation to bring to life a wide range of characters, according to a review published on goodreads.com.

Itzkoff also shows how Williams struggled mightily with addiction and depression and with a debilitating condition at the end of his life that affected him in ways his fans never knew.