Note, this is not my area, and not medical advice. If you need help with this you should consult an appropriately trained health practitioner.
To consult the scientific literature, do a search like "schizoaffective disorder prognosis" on Google Scholar.
For example, Robinson et al (1999) provide some relevant empirical data. The sample was 50% female and had a mean age of 25.6 (SD=6.3) years. To quote their abstract:
Background We examined relapse after response to a first episode of
schizophrenia or schizoaffective disorder.
Methods Patients with first-episode schizophrenia were assessed on
measures of psychopathologic variables, cognition, social functioning,
and biological variables and treated according to a standardized
algorithm. The sample for the relapse analyses consisted of 104
patients who responded to treatment of their index episode and were at
risk for relapse.
Results Five years after initial recovery, the cumulative first
relapse rate was 81.9% (95% confidence interval [CI], 70.6%-93.2%);
the second relapse rate was 78.0% (95% CI, 46.5%-100.0%). By 4 years
after recovery from a second relapse, the cumulative third relapse
rate was 86.2% (95% CI, 61.5%-100.0%). Discontinuing antipsychotic
drug therapy increased the risk of relapse by almost 5 times (hazard
ratio for an initial relapse, 4.89 [99% CI, 2.49-9.60]; hazard ratio
for a second relapse, 4.57 [99% CI, 1.49-14.02]). Subsequent analyses
controlling for antipsychotic drug use showed that patients with poor
premorbid adaptation to school and premorbid social withdrawal
relapsed earlier. Sex, diagnosis, obstetric complications, duration of
psychotic illness before treatment, baseline symptoms, neuroendocrine
measures, methylphenidate hydrochloride challenge response,
neuropsychologic and magnetic resonance imaging measures, time to
response of the initial episode, adverse effects during treatment, and
presence of residual symptoms after the initial episode were not
significantly related to time to relapse.
Conclusions There is a high rate of relapse within 5 years of
recovery from a first episode of schizophrenia and schizoaffective
disorder. This risk is diminished by maintenance antipsychotic drug
- Robinson, D., Woerner, M. G., Alvir, J. M. J., Bilder, R., Goldman, R., Geisler, S., ... & Lieberman, J. A. (1999). Predictors of relapse following response from a first episode of schizophrenia or schizoaffective disorder. Archives of General Psychiatry, 56(3), 241. FULL TEXT