"In the coronavirus period, loneliness has increased markedly among adolescents. They look for a sense of belonging from the Internet. Lonely adolescents head to the Internet and are at risk of becoming addicted," said researcher Katariina Salmela-Aro from the University of Helsinki.

According to the researchers, adolescents' net use is a two-edged sword -- while the consequences of moderate use are positive, the effects of compulsive use can be detrimental. Compulsive use denotes, among other things, gaming addiction or the constant monitoring of likes on social media and comparisons to others.

For the study, published in the journal Child Development, the team involved a total of 1,750 participants to investigate detrimental Internet use by adolescents. The subjects were studied at three points in time -- at 16, 17 and 18 years of age.

The risk of being drawn into problematic Internet use was at its highest among 16-year-old adolescents, with the phenomenon being more common among boys.

For some, the problem persists into adulthood, but for others it eases up as they grow older, the researchers said.

The reduction of problematic Internet use is often associated with adolescent development where their self-regulation and control improve, their brains adapt and assignments related to education direct their attention, it added.

In the study participants, compulsive Internet use had a link to depression. Depression predicted problematic Internet use, while problematic use further increased depressive symptoms.

Additionally, problematic use was predictive of poorer academic success, which may be associated with the fact that Internet use consumes a great deal of time and can disrupt adolescents' sleep rhythm and recovery, consequently eating up the time available for academic effort and performance.