The couple revealed in October (10) they had decided to take a break after 11 years of marriage.
The former Friends star has kept a dignified silence since their trial separation began, but Arquette went public to reveal their lack of bedroom action and how the actress grew tired of his immaturity - and he opened up further on Howard Stern's radio show on Wednesday (15Dec10).
When asked by the shock jock if he's "having a nervous breakdown", Arquette replied, "I believe so."
He confessed he had been drinking heavily since his marriage revelation and had "embarrassed" himself at a Hollywood party after mistaking Tom Cruise for someone else.
But despite his own claims, Arquette has taken to his Twitter.com page to insist he is not experiencing a meltdown.
He writes, "It is being reported that I'm having a Nervous Breakdown. I assure you am not. This stemmed from a joke I made.
"I always speak my mind and I really don't care what people that don't know me may say. I'm a good person with a huge heart. I thank those that have been on my side during this rough time."