The impact of an unfavorable depression course on network size and loneliness in older people: a longitudinal study in the community.

Houtjes, W., van Meijel, B., van de Ven, P.M., Deeg, D.J.H., van Tilburg, Th., & Beekman, A.T.F. (2014).  International Journal Of Geriatric Psychiatry, 29(10), 1010-1017. DOI: 10.1002/gps.4091 http://www.ncbi.nlm.nih.gov/pubmed/24615822