Loneliness may be regarded as a ‘geriatric giant’, leading to impaired quality of life, greater need for institutional care and increased mortality. For the past 30 years, a growing number of studies have focused on loneliness. However, the majority of these have been descriptive and cross-sectional. Further longitudinal studies are needed to understand the causal relationship between life-events and loneliness, its prognostic significance and, in particular, whether negative consequences may be alleviated.