Dr. Christina Pietz, a forensic psychologist, told the judge Tuesday that Loughner is "one of the worst" mentally ill patients she's ever seen.

CNN: STORY HIGHLIGHTS

Ethan has been having a hard time sleeping, she told the psychologist turned syndicated daytime talk show host.

CNN: Mom to Dr. Phil: Ethan having trouble sleeping

Professor Roger Baker, an expert in panic disorders and a clinical psychologist based at Dorset Healthcare NHS Trust, told BBC News Online that it was likely that panic attacks were caused by a mixture of genetic and environmental factors.

BBC: Panic attack gene breakthrough

CHESAPEAKE, Virginia (CNN) -- A defense psychologist testified Monday afternoon that sniper suspect Lee Boyd Malvo told him convicted killer John Allen Muhammad shot an FBI analyst to death in October 2002.

CNN: Expert: Malvo said he was spotter, not shooter

An independent psychologist has told an inquest in Cornwall the deaths of a 10-year-old boy and his parents could not have been foreseen.

BBC: House fire scene