The aim of the congress is to discuss the new developments in the understanding of non motor aspects of Parkinson’s disease and related disorders. During our meeting in Seoul we shall have an opportunity to deliberate on brain diseases and how they contribute to cognitive decline. We shall try to identify the specific psychological markers, if any, of Parkinson’s dementia and of dementia with Lewy bodies, and also the biochemical and genetic factors involved. The identification of cortical Lewy bodies and of widespread alpha-synuclein deposits in recent years has contributed to our understanding but at the same time raised new and still unanswered questions. The overlap with Alzheimer’s disease will be a central issue, as will be the Neurochemical changes seen in these disorders.