Orygen researchers are investigating how to personalise treatments for people experiencing depression, given up to 60 per cent of young people do not respond to currently available treatments.
Orygen researcher Dr Lianne Schmaal said part of the challenge was that there is not currently a way of testing for the biological markers of different types of depression.
“As opposed to illnesses such as cancer, there is not a single test that can tell us that this person will benefit more from this antidepressant, whereas that person might be better off with a certain type of psychosocial intervention,” Dr Schmaal said.
“Depression is very heterogeneous, meaning that different people with depression have different symptoms but likely also differ in the underlying causes of their depression.”
Previous Orygen research has shown that 30–60 per cent of young people do not respond to treatment with antidepressants or psychotherapy.
Orygen researchers are aiming to improve those statistics by searching thousands of brain images for biological makers of different types of depression.
But first they need to find what a young person’s brain ‘normally’ looks like.
Johanna Bayer, a PhD researcher in Dr Schmaal’s team, is working that out by analysing clinical and brain imaging data collected from more than 10,000 people as part of the ENIGMA Major Depressive Disorder consortium.
“I’m looking at 72 different regions of the brain and comparing different characteristics of the brain regions, such as their thickness, surface area and volume,” Ms Bayer said.
“We are trying to develop a model that should eventually map the ‘normal’ brain structure for each of those regions of a young person of a certain age and sex – akin to the growth charts we have for height and weight.
“We can then use these brain ‘growth charts’ to see if the brain of a young person with depression differs from normative curves, which may help to inform the type of treatment for that young person.”
Meanwhile another Orygen PhD researcher in Dr Schmaal’s team, Yara Toenders, is analysing the ENIGMA data for differences in brain structure between people with different types of depression.
“What Yara has found is that there's a sub-group of young people that has more atypical depressive symptoms,” Dr Schmaal said.
“In addition to sad mood, diminished interest or pleasure in most activities, cognitive symptoms, the typical kind of depression presentation usually also includes decreased appetite, weight loss and insomnia. But there is a sub-group that actually shows an increase in appetite, weight gain and hypersomnia.
“On a symptom level these seem to be quite opposite groups so you can imagine that there might be different biological mechanisms underlying this.”
Dr Schmaal hopes this work will ultimately lead to personalised depression treatments.
“If we can find treatments that work quicker and relieve depression more effectively then we can improve outcomes across the lifespan,” she said.
“Studies show that an early stage intervention with the right medications or treatment is associated with better outcomes.”
Orygen’s work on the ENIGMA MDD consortium data is supported by several US National Institutes of Health Research grants awarded to Dr Schmaal (RO1 MH117601, RO1 MH121246, RO1 MH116147A, R56 AG058854).