Schizophrenia and attention deficit disorder. Two complex disorders of attention.

Attentional dysfunction can be found in nearly every form of psychopathology, not just in attention deficit disorder (ADD). Being able to distinguish ADD from other psychiatric conditions is crucial for clinicians working with adolescents and young adults, particularly in the case of psychoses where making the correct diagnosis and beginning treatment promptly is extremely important. In this paper we review the literature on the attentional dysfunction found in schizophrenia and compare it to that found in ADD in an effort to increase our knowledge of etiology and underlying mechanisms. Investigators studying ADD may learn from the study of schizophrenia by realizing that ADD is also a complex disorder of attention that occurs across the developmental spectrum and is characterized by various predispositional, environmental, and maturational factors.