Comedian, actor, writer, producer, and director - Harold Ramis has, it seems, tried his hand at everything in the entertainment business. After starting his career writing and performing comedy on TV, he made his most memorable movie appearance as the nerdy Egon in the "Ghostbusters" movies. His directing credits include "Caddyshack", "Grounhog Day", and the film he talks about here, "Analyze That".

Did you see a difference between De Niro's comedy roles between the first and second films?

He's remarkably self-possessed. Whatever he's doing, whether it's comedy or drama, he gives the same consideration to everything. He's really open. Sometimes I'd try to speed through certain things, but he'd say, "No, wait, wait, wait, let's consider that."

Robert De Niro sings in this movie. Tell us about that...

There were questions for us. Should he sing well? Should he not sing well? Should we use his real voice? Should we re-voice him with a professional singer? But we went with his real voice.

How is this film different from the first one?

It's three years downstream. Our lives are so different. We had all been through a lot of personal issues so we all had different priorities. We'd done it before, so there was a little bit of déjà vu and I think our investment was different. But everyone's so good at what they do. These guys are so excellent.

What is the secret with Crystal and De Niro? Why do they play off each other so well?

Comedians are usually hogs. They just love the attention of being up there alone. So it is always dangerous when you put a stand-up comedian in a film. But Billy is so incredibly generous. The thing you'd never expect is for a stand-up of his stature to be able to play this kind of role. One which is passive and reactive - which is what he had to be as a therapist. He knows he can't be firing one-liners at his patient. I think Robert appreciates that. And he gets to play off Billy's strengths as a therapist. At the end of the first movie, I said to Billy, "I would like you to be my therapist. That's how good you were in this part."