||Background: To study late-life depression and its unfavourable course and co morbidities in The Netherlands.
Methods: We designed the Netherlands Study of Depression in Older Persons (NESDO), a multi-site naturalistic
prospective cohort study which makes it possible to examine the determinants, the course and the consequences
of depressive disorders in older persons over a period of six years, and to compare these with those of depression
earlier in adulthood.
Results: From 2007 until 2010, the NESDO consortium has recruited 510 depressed and non depressed older
persons (≥ 60 years) at 5 locations throughout the Netherlands. Depressed persons were recruited from both
mental health care institutes and general practices in order to include persons with late-life depression in various
developmental and severity stages. Non-depressed persons were recruited from general practices. The baseline
assessment included written questionnaires, interviews, a medical examination, cognitive tests and collection of
blood and saliva samples. Information was gathered about mental health outcomes and demographic,
psychosocial, biological, cognitive and genetic determinants. The baseline NESDO sample consists of 378 depressed
(according to DSM-IV criteria) and 132 non-depressed persons aged 60 through 93 years. 95% had a major
depression and 26.5% had dysthymia. Mean age of onset of the depressive disorder was around 49 year. For 33.1%
of the depressed persons it was their first episode. 41.0% of the depressed persons had a co morbid anxiety
disorder. Follow up assessments are currently going on with 6 monthly written questionnaires and face-to-face
interviews after 2 and 6 years.
Conclusions: The NESDO sample offers the opportunity to study the neurobiological, psychosocial and physical
determinants of depression and its long-term course in older persons. Since largely similar measures were used as
in the Netherlands Study of Depression and Anxiety (NESDA; age range 18-65 years), data can be pooled thus
creating a large longitudinal database of clinically depressed persons with adequate power and a large set of
neurobiological, psychosocial and physical variables from both younger and older depressed persons.