Happiness is about what the title indicates, or rather, the lack thereof.
Characters in Solondz's garishly unsettling portrait of troubled love and relationships all strive for that wonderful, life-assuring high known as happiness. And happiness evades them, each and every one. But, thematically speaking, Solondz's film is entirely different. He pens characters from an alternate perspective. Happiness isn't merely black, it's a black hole.