-Strike during late adolescence
-Affect men very slightly more than women, and seem to occur in all cultures.
-Paranoid, disorganized, catatonic, undifferentiated, and residual.
-Disorganized and delusional thinking, disturbed perceptions, and inappropriate emotions and actions. Delusions are false beliefs; hallucinations are sensory experiences without sensory stimulation.
-Schizophrenic symptoms may be positive (the presence of inappropriate behaviors) or negative (the absence of appropriate behaviors).