Patients with neurological disorders are particularly susceptible to a variety of affective and mood disorders. Unfortunately, several factors confound the analysis of the individual case. These factors include the fact that neurological deficits may limit the capacity of the individual to communicate mood and feelings. In some cases, the deficits might mimic affective disorders. In this article we will review the traditional presentation of affective disorders in the normal patient. We offer a discussion of specific aspects of the neurobehavioral assessment that might confound the analysis of the individual case. The confounding factors include frontal lobe deficits, aspects of impairments in language, and memory disorders. We also direct attention to motor system deficits and other problems such as sleep disorders that might contribute to a better diagnosis of affective and mood disorders. Finally, we summarize this information and present a general approach for the analysis of the individual.