Handout / Reuters

Dr. Phil McGraw is shown with Jennifer Kirkland during a taped exclusive interview to be aired February 13, 2013 in this still image taken from video courtesy of CBS. Kirkland's six-year old son Ethan Gilman was held hostage in an underground bunker for nearly a week by Jimmy Lee Dykes before being rescued by FBI agents.

The six-year-old Alabama boy kidnapped on his way home from school and held for seven days in an underground bunker is having difficulty sleeping and is troubled by the sight of school buses, according to the boy's mother.

Jennifer Kirkland, mother of the boy identified by officials only as Ethan, gave her first interview to Dr. Phil McGraw for an episode of the "Dr. Phil Show" set to air Wednesday.

A preview of the show posted online reveals that Ethan saw officers fatally shoot his kidnapper, identified as Jimmy Lee Dykes.

"He said, 'The Army came in and shot the bad man,'" Kirkland said.

Federal agents raided the underground bunker on the sixth day of the standoff when the 65-year-old Dykes thought he would be receiving a delivery.

Though Ethan was not physically injured, Kirkland expressed concerns over the long-term mental effects of the trauma.

"I'm scared of how he's going to take getting on a bus," she said. 

During the standoff officials had reported that the boy suffered from Asperger's syndrome.

Ethan, who has yet to return to school, was taken hostage on January 29 after Dykes boarded his school bus and demanded the bus driver turn over two children, according to authorities. When the driver refused, Dykes fatally shot the driver and took Ethan.

"He has said a few things I know that he is having a very hard time sleeping soundly," said Kirkland. "He slings his arms and tosses and turns and he's cried out a few times."

In an interview with ABC's "Good Morning America," McGraw said that Ethan's captor developed empathy for the boy, frying him chicken and taking care of him in the small bunker.  

According to his mother, Ethan has said only a few things about his captivity. "I think he understands there was a very violent act. I think it scared him greatly," McGraw said.