TEENAGERS are launched onto a slippery slope of insomnia and poor mental health once they start delaying their bed times according to a new university study from South Australia.

The University of Adelaide research reveals the delicate juggle between sleep, study and social pressures our young adults regularly experience.

"In adolescence, the older the child becomes the more likely they are to show a preference for being awake in the evening," said study leader, PhD candidate Pasquale Alvaro.

"This is due to biological factors, but also social factors like academic stresses or use of technology like phones and tablets."

"Then they have to turn around and get up early for school the next day, and this can start a pattern of sleep deprivation," he said.

To conduct the study, Alvaro surveyed more than 300 high school students aged 12-18.

Teens who were more active in the evenings were more likely to have depression or insomnia, or both. This group was also more likely to have obsessive-compulsive disorder, separation anxiety, and social phobia.

The study suggests that the approach for treating teenagers for mental health disorders should take sleep into account.

"We need to communicate to teachers and parents that some behavioural issues may feature sleep deprivation as a contributing factor," said Alvaro.

"In my opinion measuring sleep should be part of any mental health assessments performed in teenagers."

Alvaro's study was published in the journal Sleep Medicine.