Can a schizophrenic pass a lie detector?

Some can.

Sometimes sociopaths (antisocial personality disorder) can lie but still pass a lie detector test, but the reason isn't because they're experienced liars, but because feel little or no guilt about deceiving people, so they register few biological stress indicators.

"Compulsive liar" isn't a mental health diagnosis, but a descriptive term for someone who lies habitually, regardless of the reason. While some of these people may be sociopaths, many more are people who experience guilt, anxiety, fear and other feelings related to their deceptions that would make it virtually impossible for them to fool a polygraph examiner.