Teenagers who are overweight or obese are more likely to have considered suicide than those who are a normal weight, according to new research presented at a meeting of the Royal College of Psychiatrists' Child and Adolescent Faculty.

Researchers from the University of Liverpool measured the height and weight of 799 Year 9 students from five comprehensive schools in Cheshire. This was used to calculate each student's body mass index (BMI).

The researchers also asked the pupils to complete questionnaires, including a Mood and Feelings questionnaire, which asks about suicidal ideation (thinking about suicide with some degree of intent), and an Eating Disorders Inventory (EDI). The pupils' EDI scores were compared with those of 174 adolescents of the same age and sex who were known to have the eating disorder anorexia nervosa.

The researchers found that the prevalence of suicidal ideation was 13.3% (11.1% in boys and 15.5% in girls).

A linear relationship existed between suicidal ideation and BMI, with overweight and obese adolescents experiencing the highest rates of 26.8% - more than twice the average prevalence for the entire group.

Adolescents of both genders who had suicidal ideation were also found to have significantly higher EDI scores, meaning they had high levels of dissatisfaction with their bodies and a high drive for thinness. However, these scores were not as high as among the group with anorexia nervosa.

The researchers concluded that being overweight or obese - together with associated dissatisfaction with weight and shape - may be a significant risk factor for suicidal ideation in adolescence in both sexes.

Royal College of Psychiatrists' Faculty of Child and Adolescent Psychiatry Annual Residential Conference, 17-19 September 2008, Britannia Adelphi Hotel, Liverpool

The Royal College of Psychiatrists