Patch Adams is a real-life doctor, and quite a significant one as it happens. He runs the groundbreaking Gezundheit Institute, where laughter has become a central part of the curing process. It's important to point this out, because watching this, you'd swear the guy had lived his life just so Robin Williams could make the movie.
Some time ago, Robin Williams graduated from being a movie actor into an entire genre, and Patch Adams is every inch a Robin Williams Movie. Patch Adams' life story plays like a highlight reel of Williams career so far: he's an unorthodox idealist who's loved by his patients but reviled by his seniors (Good Morning Vietnam); he's wilfully eccentric and quite possibly insane (The Fisher King) and he stumbles upon a radical new medical treatment (Awakenings). The list could go on...
This plot familiarity is further compounded by Tom Shadyac's slack direction, which allows Williams an apparently free hand in recreating his usual mixture of mawkish and manic: "Why look, here's Robin the clown. He does this without a script you know? And look! Now Robin's being all serious. Oh my, is that a tear in his eye?"
As for the rest of the cast... well they're simply slotted into archetypal Robin Williams Movie supporting roles: there's the bumbling rival (Hoffman); the shy acolyte (London); the romantic interest (Potter) and - - TA DAH! - - even the trusty evil authority figure (Gunton).
In some ways Patch Adams is not a bad movie, shamelessly but successfully manipulating your emotions. But in another, realer sense, it is a bad movie - - and despite the interesting source material and steady supply of gags, there's no escaping the fact that Williams has played this part far too many times before.