[Photo/Xinhua]

Late night mobile phone use has devastating effects on teenager's mental health, a new study by Australian researchers at Murdoch and Griffith Universities found Tuesday.

Funded by the Australian Research Council, the world's first long-term assessment of adolescent mental health regarding late night mobile phone usage examined student's quality of sleep, along with mood, aggression, coping skills, self esteem and whether they were experiencing any symptoms of depression.

The process was conducted as an annual survey over four years and included 1,100 students from 29 schools.

When the subjects began the process, they were in year eight of high school, when the program concluded, they had hit year 11.

The questionnaires focused on what time of the night students continued to receive or send text messages and phone calls.

"We found that late night phone use directly contributed to poor sleep habits, which over time led to declines in overall wellbeing and mental health," lead researcher, Dr Lynette Vernon said.

"We have demonstrated how poor sleep is the key link connecting an increase in night-time mobile use with subsequent increases in psychosocial issues."

Around two thirds or 65 percent of students in year eight who owned a mobile phone, reported to use it regularly after "lights out."