This study asks if the prevalence of loneliness in the population varies depending on the measures used, with special focus on loneliness among the elderly. The study compares loneliness in different age groups between 18 and 81 years old (N = 14,743) using two measures of loneliness: the (indirect) six-item De Jong Gierveld Loneliness Scale and a single-item, direct question about loneliness. Data are from the Norwegian LOGG (Life Course, Generation, and Gender) study. We compare the findings on loneliness according to age, gender, health, and partner status. Overall, the two loneliness measures indicate a similar prevalence of loneliness, but attribute loneliness to somewhat different people. When using a direct measure, loneliness is more prevalent among women; when using the (indirect) De Jong Gierveld Scale, loneliness is more prevalent among men. Also, the association between age and loneliness differed when using the direct and the indirect measure.

The findings strengthen the notion of the need for family-oriented support, combined with person-centered care for the children according to their needs. In addition, group meetings and contact with other young people in the same stage of life could be of interest for some.

The results demonstrate that loneliness is influenced by events and experiences from early childhood to later life, and that some events and experiences influence loneliness in men and women differently.

The interviews showed that spouses and the whole family of yo-FTLD need interdisciplinary, individualised and specialised support throughout the progression of the disorder. Furthermore, there is a need for more knowledge about yo-FTLD among health personnel, including general practitioners. IT-solutions can contribute to developing such services and support to the entire family.

Preventing and reducing loneliness is crucial to well-being and good health. Social relationships protect people against loneliness. Friendship qualities like intimacy and frequency of contact may vary throughout a person's lifespan. This study explores aspects of friendship and loneliness among people in different age groups: 18 to 29, 30 to 49, 50 to 64, and 65 to 79 years old. Data are from the Norwegian Life Course, Gender and Generations study (N ¼ 14,725). Young people see their friends most often. The proportion of people without confidant friends is higher among older age groups. However, older age groups report higher levels of satisfaction with their contact with friends. Multivariate regression analyses show that the aspiration for contact with friends is more significant to loneliness than actual contact in all age groups. Dissatisfaction with contact with friends is strongly related to loneliness in all age groups.