Marcus Schrenker said he understands the Dr. Jekyll and Mr. Hyde comparison thrust upon him in the wake of allegedly attempting to fake his own death.

"I can see that," Schrenker, formerly of Merrillville, told The Times. "There is some truth to that."

Schrenker described at length the mental swings he said he has been suffering for years, including when he was diagnosed as bipolar as a student at Purdue University.

"The reason it's called bipolar (is) you're talking about swaying between very high, manic moods and very low, depressive moods," said David Simpson, assistant professor of counseling and psychology at Valparaiso University.

Simpson has not treated Schrenker, and commented generally on bipolar disorder -- not on Schrenker or his mental state.

Simpson said bipolar behaviors can be as varied as the people diagnosed with the disorder. Typically, bipolar disorder is characterized by cycling periods of mania and deep melancholy, Simpson said.

People suffering from bipolar disorder can have inflated, grandiose opinions of themselves, a diminished need for sleep and rapid speech, Simpson said. He said those diagnosed as bipolar often exhibit poor judgment, usually occurring while the person is on a manic high.

"They just do foolish things," Simpson said. "They put themselves in danger, basically."

Those suffering from bipolar disorder often sandwich periods of manic behavior -- such as overspending large amounts of cash -- between a functioning normalcy, Simpson said.

Simpson said bouts of mania can last for several days, with the person making poor decisions throughout the cycle. He cast some doubt that a person suffering from bipolar disorder might create and execute a lengthy traumatic event for days at a time.

Prosecutors said Schrenker ditched his plane on Jan. 11 over Alabama and retrieved a stashed motorcycle to drive to Florida, while letting his plane crash into Florida swampland.

"I would lean towards doubting it, but I would not exclude it," Simpson said. "It is possible for a person to be planful. It's theoretically possible."