Paul Nassif -- My Wife Attacked Me After Guzzling Vodka

Paul Nassif is Absolut-ly convinced ... vodka turns his wife Adrienne Maloof into a violent, abusive, angry woman who was prone to smacking him in the face.

According to a declaration -- filed in his nasty custody fight -- Paul claims he has been repeatedly at the receiving end of Adrienne's physical attacks ... the worst of which occurred in July on Maloof's home turf in Las Vegas. Paul says they got into a spat over whether Adrienne's mother could come to a party. Paul says his wife downed 4 vodka sodas -- with a little grapefruit juice -- and became "increasingly hostile."

Paul says Adrienne went on a 45-minute rampage, physically and verbally demeaning him. He says she accused him of cheating and calling him a piece of s**t. Paul says Adrienne screamed he was a horrible dad, and repeatedly beat him in the face, chest and legs.

TMZ previously reported Adrienne filed legal docs claiming Paul has an explosive temper and carries a gun ... sometimes in easy reach of her children. She mentions she took a photo of the gun in the side pocket of his briefcase.