Breaking News Emails

Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.
By JoNel Aleccia

Reports that the shooter who killed a dozen people in Monday’s Washington Navy Yard attack was hearing voices raises the possibility of mental illness -- but it’s not a diagnosis, experts say.

“I think it’s too early to tell what the real motivation was in this recent case,” said Dr. Jeffrey Lieberman, president of the American Psychiatric Association.

Aaron Alexis, the 34-year-old gunman, appeared to report auditory hallucinations when he called police to a Rhode Island hotel six weeks ago and said he was hearing voices in the closet and wanted to move to a Navy hotel.

Such hallucinations are the hallmark of psychiatric disorders; about 75 percent of those diagnosed with schizophrenia experience voices that they can't explain. They’re also common in up to half of cases of bipolar disorder and in about 40 percent of post-traumatic stress disorder cases, psychiatrists say.

But they're not always critical, shaming voices that urge people to commit violence. In fact, many people with no disorder also report hearing voices -- and they’re often neutral, even innocuous, said Lieberman, who’s also a professor and chairman of psychiatry department at Columbia University.

“A larger than you would think portion of people in our population have these hallucinations,” Lieberman said.

“You can have things which are pleasant, such as music. You can have voices that may be grandiose and extolling your praises,” he added. “And you can also have auditory hallucinations that are completely neutral … voices talking to each other and it's just background chatter, like a crowded room or a cocktail party.”

There’s no way to know whether Alexis heard voices that said derogatory things about him or instructed him to commit violence.

“The most pernicious type of hallucination and the one that’s the biggest risk factor is the so-called ‘command hallucinations’ that tell you to do something,” Lieberman said. “Once they become strong enough, they can’t distinguish these as external fabrications, they are under the influence of the voices.”

Such hallucinations can be resistant to treatment with anti-psychotic drugs and with counseling, experts say.

As more details emerge about Alexis, Lieberman said he was concerned that the shooting renews worries for people with mental illness and once again raises questions about how society treats disorders.

“I think it immediately arouses fears and enhances stigma about people with mental illness, that they’re psychotic killers and wackos running amok,” Lieberman said. “It’s unfortunate.”

Instead, there needs to be more focus on diagnosis and treatment of people with psychiatric disorders, a call that seems to be raised routinely after tragedies such as Monday’s shooting – and the attack in Newtown, Conn., last December.

“We remain unaware, uniformed and fearful of what disturbances in brain function can lead to,” Lieberman said. “Everyone talks about it and nobody does anything about it."