Depends. The thought disorder from schizophrenia you speak of may be different from a communication disorder. A communication disorder may start at a very young age and could begin in childhood.. Schizophrenia has for it's most common age of onset the late teens or the early 20s. Cases of schizophrenia in a young child are rare and atypical.
Starts Young Adults. Schizophrenia can occur at almost any age, but it is rare in chidlhood. The symptoms of schizophrenia most commonly begin in mid to late adolescence with full blown difficulties in early adulthood. It is very unusual for schizophrenia to suddenly begin in mid to late adulthood.
Is it possible that thought/communication disorders occur at 18 years old stemming from schizophrenia?
Yes, that is the age. Perhaps the most likely age range for appearance of schizophrenia is 17 - 24. Thoughts as well as communication are often areas that are noticed to be different than before. Other symptoms would also be necessary for a firm diagnosis, but it is a possible one. Find a really good psychotherapist with experience in evaluation of psychosis and alternative neurological problems. Good luck. Read more...