Overweight children have an increased risk for a long-list of diseases and conditions such as asthma, diabetes, and high blood pressure. In addition to physical complications, their mental health can be affected too. New research suggests that children who are overweight have a greater risk of suffering from depression into adulthood.

In an observational study, researchers found that being overweight at age 8 or 13 was associated with triple the risk of developing depression during their lifetime. They also found that carrying excess weight as both a child and adult quadrupled their chance of developing depression compared to only being overweight as an adult.

“Our findings suggest that some of the underlying mechanisms linking overweight or obesity to depression stem from childhood,” the authors conclude in a statement.

Although previous studies have associated obesity and depression, this is one of the few to look specifically at how childhood obesity affects a person during an extended period of time.

The study, presented at the 2017 European Congress on Obesity, involved data from 889 participants in Reykjavik, Iceland born between 1907 and 1985. Information about their height and weight at various points in their life was assessed. Then years later, when the subjects were on average 75 years old, they were asked about their history of depression. The results revealed 39 of the surviving participants had been diagnosed with major depressive disorder at some point. When the obese participants were then compared with normal weight children who became overweight later in life, the researchers found the obese children had more than 4 times the risk of lifetime major depressive disorder.

“Given the rise in adolescents’ obesity and greater influence of social media on body image, understanding the associations between childhood obesity and depression is critical,” said the authors.

Since the 1970s, the percentage of obese children has more than tripled in the United States. Today, about one in five school-aged children has obesity, according to the Centers for Disease Control and Prevention.

A child is diagnosed with obesity by assessing where their body mass index (BMI) falls on a growth chart that corresponds with their age and height. Since BMI does not account for muscle mass or larger than average body frames, a doctor also considers other factors to determine if the child's weight is a concern. Some of the factors include: family history of obesity, the child’s eating habits and activity level, as well as their psychosocial history. If the child is determined to be obese, treatment will involve changes in diet and physical activity. For certain patients, medication or weight-loss surgery may be an option.