Question about schizophrenia?

Hello, I am a 25 year-old caucasian male who has had major depression for about 6-7 years; i have been treated with some success for the past year or so; my psychiatrist recently noted his concern, however, that I was demonstrating certain early signs of schizophrenia; notably the so-called negative symptoms, i.e. lack of warmth, motivation or ambition, lack of emotional responsiveness, flat affect, little concern about socializing with others or developing intimate relationships; also, he mentioned my continuing insomnia as well; I do not currently experience any "positive" symptoms of schizophrenia, such as auditory or visual hallucinations, or psychosis; my question is, what is the likelihood I will develop schizophrenia in the months/years ahead? My doctor said "unlikely" because I am a little old--25-- and he stated that it is most likely schizoid personality disorder; how accurate is this, am i really too "old", and where can I find info on schizophrenia and related disorders?