Dysfunction of the frontal lobes usually results in behavioural abnormalities. In recent years, the crucial importance of the frontal lobe for working memory functions has become apparent. Vascular lesions extending into the frontal white matter have been found to be associated with depression, particularly in the elderly. The understanding of frontotemporal dementia has most rapidly developed. There is a strong input from genetic research, aiming at basic mechanisms of degenerative brain disease.