According to various medical journals, 6.3% population suffers from smartphone addiction. This addiction is greatest among young adults less than 30, with an average of 16% of teens addicted.
There is no particular underlying cause, scientists believe that it is due to the release of Dopamine, a happy hormone. This hormone is released every time we get a notification, message, alert, etc on our phones.
A proper insight into smartphone addiction is still in infancy and therefore no confirmed risks are known that can trigger this disorder. However certain psychological factors such as low self-esteem, anxiety, impulsivity, stress, and a history of substance abuse and social alienation, can trigger smartphone addiction.