Is Mel Gibson suffering from an identifiable mental illness? With audio evidence of Gibson's profane, seemingly unhinged calls to his former girlfriend, Oksana Grigorieva, mounting daily, journalists are confronting mental-health experts with that question. (Watch some celebrities shares their thoughts.) While the actor-director has publicly battled an alcohol problem and claimed in 2008 that he'd been diagnosed with bipolar disorder, some authorities say these tapes suggest more than a mere manic or drunken episode. Here are four theories:

1. Gibson is a textbook abuser
Telling Grigorieva that she deserved to be hit and that she's forced him to behave this way — these are classic domestic-abuse scenarios, says Lundy Bancroft, author of the book Why Does He Do That? Inside the Minds of Angry and Controlling Men, as quoted in The Daily Beast: "The domestic batterer always takes the stance that it's this particular woman's behavior that has caused him to become violent. That’s all over the place in this tape."
"Mel Gibson: Classic batterer?"

2. He's a "sociopathic personality"
Dr. Dale Archer, a psychiatrist and founder of The Institute for Neuropsychiatry in Lake Charles, Louisiana, tells ABC News that "these episodes of rage followed by apparently normal periods in between" are "a classic symptom of bipolar disorder," but another expert consulted by ABC News disputes the manic-episode theory. Psychologist Melody Anderson says the tapes instead suggest "a sociopathic kind of personality… with absolutely no remorse and no ability to have sympathy for someone in pain."
"Mel Gibson: Mentally ill or maybe just a jerk?"

3. He's a narcissist with a warped perspective
Other aspects of the recordings argue against bipolar disorder, says John M. Grohol, PsyD, at Psych Central. "Focusing on one's own feelings and how another person’s behavior affects us" is more typical of "narcissism," a personality disorder common to celebrities who have been worshipped and catered to for years. Gibson also demonstrates a warped perspective: "Such a discrepancy in perspective or connection to reality can be a sign of a psychotic break."
"Mel Gibson, bipolar disorder and alcohol"

4. He suffers from panic attacks
Salon's Sarah Hepola consulted Steven Stosny, a therapist and author who specializes in chronic anger and abusive relationships. Stosny notes that Gibson is audibly panting in the recordings, a classic indication of a panic attack: "These calls are obsessional," says Stosny, who further speculates that an amphetamine-like drug may be amplifying Gibson's condition. "Anger is a natural amphetamine," Stosny says. "If you add an amphetamine, even caffeine, it becomes more intense."
"The psychology of Mel Gibson's rage"