Researchers have identified poor sleep, bullying and family trauma as common risk factors among suicidal teens admitted to hospital.

Poor sleep, bullying, sexual abuse and living in a single parent home have been identified as common risk factors for suicidal behaviour among Australian adolescents.

Researchers at the Murdoch Childrens Research Institute reviewed of all admissions to the mental health unit at Royal Children's Hospital in Melbourne between October 2013 and September 2014.

There were 271 adolescents admitted during the period, with 212 (78 per cent) due to suicidal behaviours.

Most participants were admitted on one occasion only, with one-quarter (25.5 per cent) admitted prior to the age of 10.

More than three-quarters were diagnosed with one or more mental disorders at the time of discharge, the most common being major depressive disorder (MDD).

Further analysis found three quarters had trouble sleeping, while almost two thirds had a history of bullying.

The majority were also female and more than half had a history of significant family trauma, 33 per cent of admitted adolescents had disclosed or suspected sexual abuse and 34 per cent had disclosed or suspected physical abuse.

More than half (65.6 per cent) reported their parents were no longer together.

With the findings published in the Journal of Paediatrics and Child Health, the researchers hope they will help to reduce the adolescent suicide rate.

"The very high proportion of admissions to the mental health inpatient unit accounted for by suicidal behaviours reinforces the importance of finding effective methods of identification of the risk processes underpinning suicidal behaviours in order to reduce the unnecessary waste of young lives by suicide," the authors wrote.

Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14.