Below is a query sent to my "mailto link" at my hospital's website, plus my response to it.  On many levels, the question hit me where I live.

"Dear Sir or Madam,"

--Madam.  I am Dr. Kay McCrary.  I authored the handout about schizophrenia posted at our website.  I am the Director of Patient & Family Education at Bryan Psychiatric Hospital.

"Hi! I am currently doing research on schizophrenia. I am writing a story
and would like to be as accurate as possible."

--I commend your commitment to accuracy.  I hope nothing stigmatizing would result from someone reading your story.  Accuracy will avoid the temptation to sensationalize in order to add interest/drama/thrill to the story.

"Could you tell me, if a teenager has a mother who is schizophrenic, could he have behavior that might make him think he has schizophrenia without actually having it? If yes, what might that behavior be?"

--I can answer that one from personal experience.  I had an aunt who was diagnosed as having paranoid schizophrenia, and she had to move into our home when I was 12 years old.  She shared my bedroom.  And she kept getting sick.

My aunt thought the FBI had a special interest in tracking her.  She came to believe that the FBI had her staked out from a headquarters in our attic.  --She could hear them, so it was very convincing to her.  Hey, she heard it with her own ears!  But she was having auditory hallucinations.  Any effort to convince her of everyone else's reality made her believe that you had joined the conspiracy.

My father was her older brother.  He is a devoted family man who loves his family.  He is into "caretaking" in a major way --high "nurturance".  He didn't want his sister on the back ward of a state hospital.  (As a result, he put his wife and two daughters through some serious hell.)  He kept thinking that he could reason his sister out of her delusions.  For example, he took her up the folding staircase to our attic and used his flashlight to show her that no one was in the attic nor could be because our attic did not even have a floor, just pink insulation between roof beams!  But my aunt still believed the FBI was up there.

We lived in a small town of about 6000 people.  Everybody knew everybody, and superficially knew their personal business.  My father supported his sister's need to be as normal as possible by encouraging her to be employed in our family's clothing store.  She behaved a bit strange.  She chuckled to herself, always smiling a private smile, having a private secret based on her private reality.  My classmates from school asked me why she was always giggling strangely.  (They didn't know the half of it!)  Of course I was embarrassed.  It definitely reflected on me.  Somehow I ended up sharing the ridicule of being strange.

There were other challenges for me beyond my aunt.  I was an overweight teenage girl, which has horrible social stigma.   Also I was intellectually smart, which unfortunately led to "breaking the curve" on tests, which made fellow students dislike and censure me.  The adjustment to high school was extremely difficult for me.  At the same time, my parents begin to have fights over the strain in our household, a large percentage due to my sick aunt.  My mother talked of leaving.

I developed a depression which was not handled well at all.  The high school counselor (whose expertise was placement testing) told my mother that, based on our family history, I might not be able to finish high school --in other words, I would be schizophrenic like my aunt.  There was no external support or encouragement for me anywhere during that awful period of my life.

Fortunately I trudged doggedly through it, bearing the pain.  The one thing that helped was my fantasy about expressing my pain as art, like Van Gogh or Dostoyevsky.  I graduated first in my class.  I went to college and double majored in art and literature.  I married a psychologist --he was the only person I could bring home to meet my family.  He and I both went on the finish our doctorates.  Now we both work at Bryan Psychiatric Hospital trying to help patients and families get on the right track to have good lives.  (Often they don't listen to us.)

"For example the pressure of dealing with a parent severely mentally ill, pent up anger and teen aged aggression, suffering the social stigma of having a mother mentally ill from school mates, getting no support from his father to handle his mother's illness, could the teenager confuse his inability to deal with his mother and these pressures as signs of his developing schizophrenia?"

--ABSOLUTELY.  You clearly have empathetic talent.  John Keats called this "negative capability", to be able to enter into the situation.

About what behaviors your main character might have that would be confused for schizophrenia but actually not be-- try a panic attack.  I was at home alone from school one day because I was "ill" (possibly due to being depressed; depressed people dwell on physical symptoms trying to deal with feeling bad).  My parents were at work at our family store.  I very definitely heard footsteps coming down the wooden floor of our hallway toward the room where I was.  I totally panicked, ran from the house, would not go in again alone.  It was awful.  In retrospect I think I was "spooked" and was listening to my own heartbeat.  Maybe my aunt's preoccupation with the conspiracy in the attic got through on some level to the awkward 13-year-old.  This was probably a turning point experience in how I was undermined in the regard of my parents and the school counselor.

"I would appreciate any assistance you could give me on this matter."
--I hope this helps.  Best wishes with your story. I would very much like to read it.  You know, stigma against people who have mental illness is very real, yet the sad truth is that the victim of the illness is innocent, has no choice in having the illness, deserves no blame.  The entire situation deserves love, compassion, understanding and support.  By giving "faces" to the people who are struggling to cope with the "hard hand they were dealt", the storyteller genuinely helps: s/he does not allow the reader to push the characters aside as the "faceless them" who can be disregarded.