Organic Mental Disorders and Psychiatric Issues in the Elderly

Cognition includes all forms of knowledge and awareness, such as perceiving, learning, conceiving, remembering, reasoning, judging, imagining, speaking, and conducting interpersonal relationships, performing actions, and solving problems. Along with affect and conation, cognition is one of the three traditionally recognized components of the mind. This chapter aims at discussing the main clinical conditions that may present with cognitive alterations: delirium and neurocognitive disorders. Delirium is a sudden and transient organic mental disorder characterized by a disturbance in consciousness, cognition, perception, and attention, while neurocognitive disorders (NCD) are conditions characterized by an insidious and progressive decline in cognition involving one or more domains. Several medical and neurological conditions can lead to organic mental disorders that, in turn, are often associated with psychological and behavioral symptoms, such as depression, anxiety, apathy, sleep disturbance, agitation, and psychosis. As these symptoms presents sometimes as the first manifestation of an underlying NCD, psychiatrists play a critical role in the assessment, diagnosis, and treatment of these complex conditions.