hi esther,
it could be a symptom of schiz, but it could also be part of something else, like depression,a anxiety disorder, a personality disorder, etc.

I think in order to fit "criteria" for schizophrenia, the person has to have 2 or more of these symptoms: delusions, hallucinations, disorganized speech, and Negative symptoms. That doesnt mean that there aren't more symptoms common with schizophrenia, but the ones i just listed are required for a diagnosis.

good luck

-Becka