The lawyer for a Kentucky man accused of strangling his wife argued at trial Monday that excessive caffeine from sodas, energy drinks and diet pills left the defendant so sleep-deprived and mentally unstable that he falsely confessed to the killing.

Attorney Shannon Sexton said in opening statements at the murder trial of Woody Will Smith, 33, that he did not kill his 28-year-old wife, Amanda Hornsby-Smith, on May 4, 2009. The lawyer also told jurors that the man's statements to police were made under high stress prompted by large amounts of caffeine and a lack of sleep.

"As a result of his altered state, Woody Smith provided a false confession," Sexton said.

The argument was a twist on Sexton's previously stated defense as outlined in earlier court documents — that a high intake of caffeine rendered Smith temporarily insane and unable to form the intent to kill his wife.

In arguments Monday, Sexton said DNA evidence taken from the victim's fingernails points away from his client, whom she described as lethargic, "in a zone" and "not himself" when he spoke with police.

Prosecutors, meanwhile, portrayed Smith as an angry man who attacked his wife during a fight, then strangled her with an extension cord.

Assistant Commonwealth Attorney Vanita Fleckinger told jurors that paramedics, hospital personnel and police officers saw Smith after the killing.

"Not one of them will tell you they saw any signs of insanity," Fleckinger added.

If convicted of murder, Smith could be sentenced to life in prison.

A legal strategy invoking caffeine intoxication is unusual but has succeeded at least once before, in a case involving a man cleared in 2009 of charges of running down and injuring two people with a car in Washington state.

Dr. Roland Griffiths, a professor of behavioral biology at Johns Hopkins University has noted in an unrelated study that there is a diagnosis for "caffeine intoxication," which includes nervousness, excitement, insomnia and possibly rambling speech.

Smith told Dr. Robert Noelker, a psychologist from Williamstown hired by the defendant, he remembers taking his children to school that morning. But Noelker reported that Smith remembers little else about the ensuing hours.

In the weeks preceding May 4, 2009, Woody Smith told Noelker, he hadn't been sleeping, in part out of fear his wife would take their two children and leave him.

Fleckinger said Smith found out his wife was having an affair with a co-worker. Sexton said knowledge of the affair led Smith to rely on caffeine and not sleep out of fear his wife would take the children and leave.

"The next several hours of Mr. Smith's life, were described to me as if he were in a daze," Noelker wrote in his report.

After sleeping intermittently, Smith had nap with one child he picked up from school at midday at a school near their home in Dayton, Ky., across the Ohio River from Cincinnati. After picking up the second child later that day, Smith said he went to his mother and stepfather's house.

He described feeling "out of control," weeping to the point of being unable to communicate. Smith eventually confided in his stepfather, Noelker wrote, "I think my wife is dead."

Reports and case records say at that time that he was drinking five or six soft drinks and energy drinks a day, along with taking diet pills; it all added up to more than 400 milligrams of caffeine a day.

The Diagnostic and Statistical Manual of Mental Disorders — published by the American Psychiatric Association showing standard criteria for the classification of mental disorders — defines overdose as more than 300 milligrams. That's about three cups of coffee.

Noelker said in his report that he determined Smith was open to "brief psychosis" brought on by sleep deprivation, which was caused by the heavy ingestion of diet pills and caffeine in the weeks before his wife's death.

The defense strategy recalls the case of Daniel Noble. The 31-year-old budget analyst at the University of Idaho Foundation awoke Dec. 7, 2009, after a restless night and weeks of hard work on the foundation's budget to head to a Starbucks shop, downing two large cups of coffee.

A judge concluded the caffeine-ingesting budget analyst was unable to form the mental intent to commit a crime, after authorities accused him of injuring two pedestrians with a car.