Changes in sleep or appetite could be indicative of one of three subtypes of major depressive disorder, an Orygen study has confirmed.
The study analysed data from 275 young people participating in Orygen’s Youth Depression Alleviation (YoDA) studies to identify subtypes of depression and differences in brain structure between the subtypes.
This is the second study to analyse symptom-based subtypes of depression in young people.
The results have been published in Translational Psychiatry.
The study’s lead author, PhD candidate Yara Toenders, said the research was conducted in two parts. The first identified subtypes of depression in young people while the second analysed the brain structures of participants in each subtype.
Three subtypes of depression in young people were identified: severe depression with increased weight and appetite; severe depression with decreased appetite and severe insomnia; and mild to moderate depression, Ms Toenders, said.
“We were interested in investigating subtypes of depression in young people because they’ve been found in adult populations numerous times before. But behaviours and processes such as appetite, sleep and weight gain or loss often change during adolescence. So these could look different in younger populations,” she said.
“After identifying the subtypes, we looked at the brain structures of participants in the three subtypes and compared them to young people without depression.
“We found that the surface area of the anterior insular cortex was lower in the subtype with increased weight and appetite.”
The anterior insular cortex is thought to be responsible for regulating our emotions and processing external and internal stimuli to guide our actions, decisions, motivation and rewards – including rewarding ourselves with food.
Although depression is one of the leading causes of burden of disease among young people, current treatments are not consistently effective.
“Depression is heterogeneous, with many different combinations of symptoms leading to the same diagnosis,” Ms Toenders said.
“Identifying these subtypes and difference in brain structures means we can begin to explore more effective treatments for people whose depressive symptoms match a particular subgroup.”
Ms Toenders’ research was supervised by Professor Chris Davey and Associate Professor Lianne Schmaal. The study was supported by the National Health and Medical Research Council of Australia and The Netherlands Brain Foundation.