99 out of 100 doctors* believe that Trump simply enjoys lying. But if there is a medical reason for his deception, Trump probably suffers (along with the nation) from confabulation. This would explain so much, but now the big question is "What is the best remedy?" The 25th Amendment is humane and painless, while impeachment prolongs pain for Republicans caught in Trump's distortion field.
*Dr. Ronny Jackson believes Trump's brain can live forever in a pickle jar.