Children's Self Portrait

My son--who's father has schizophrenia,  has been making self-deprecating remarks about himself as a pattern that I've seen over the past year.  He is a six year old in first grade doing really well in school and by all accounts is a healthy, smart, talented and promising young lad. The only problem is that I think he has unfortunately started to walk in his father's footsteps and has, by his mother and my observations, begun to show signs of developing mental illness later in life.
Part of me wants to think he is joking--trying to get a rise out of us, partly due to his childish expression on his face when he is asserting these unusual-for-a-six-year-old-remarks of negativity about himself. Another part of me wants to seek help for him in the form of bringing him along to my psychiatrist's appointment. 
Will it all work out for the best in the end? Or would it be best if I acted upon my instincts and sought professional help for my son?

-A Concerned Father