In a quantitative study of 4,227 adolescents between 13 and 19 years, scientists at the Norwegian Social Research Institute (NOVA) examined the extent of mental health problems among adolescents. Within the study, they compared youths with and without close friends to confide in and found that a significantly greater proportion of those lacking a close friend reported having depressive symptoms than those with close friends. Significantly, more than 1 in 3 girls, without a close friend, reported experiencing depressive symptoms (Hartberg & Hegna, 2014).

Being unable to attend school due to illness is obviously not synonymous with having no friends to confide in. However, school absence leads to less social interaction and can result in some children completely losing touch with friends (Drachler et al., 2009).

In another quantitative study of 4,526 adolescents between 13 and 19 years, researchers from the Norwegian Institute of Public Health examined factors that affected young people's psychological health positively and negatively. Of the factors they chose to study, they saw that “social support from friends” and “spending spare time with friends” were the strongest protective factors against mental disorders among adolescents (Myklestad, Røysamb & Tambs, 2012).

The findings of both studies are consistent with previous national and international studies, which show that social support from friends and peers helps to protect adolescents from mental disorders. (Hirch & DuBois, 1992; Ystgaard, 1997; Kapi, Veltsista, Kavadias, Lekea & Bakoula, 2007)