Emotional and cognitive symptomatologies, such as depression, mania, lability of mood and affect, psychosis, impaired arousal, anxiety, and irritability and aggression often occur in neurologic disorders. These neuropsychiatric syndromes significantly impair functioning and efforts at rehabilitation. Patients with brain damage are especially sensitive to the side effects of medication. When appropriate guidelines are followed, psychopharmacologic intervention alleviates these symptoms, enhances rehabilitation, and avoids impairment of arousal and cognition.