FDA Perspective on the DSM-5 approach to classification of "cognitive" disorders.

Primary "cognitive" disorders (e.g., Alzheimer's disease) often have behavioral features, just as primary behavioral disorders (e.g., schizophrenia) often have cognitive features. Drug research in recent years has expanded into targeting the full range of symptoms of both types of disorders. DSM-5 should include these associated features of each type of disorder, because acknowledging the full range of symptoms for each type of disorder has important research and treatment implications.