What's the science?
One third of females will be diagnosed with depression (major depressive disorder) during their adolescence. Resilience refers to the ability to adapt well in response to stress and bounce back from challenging life experiences. Currently, we don’t know the brain mechanisms that underlie resilience in adolescents who are at risk for depression. This week in JAMA Psychiatry, Fischer and colleagues test whether brain functional connectivity can be a biomarker for resilience in adolescent females at risk for depression (i.e. depression runs in their family).
How did they do it?
65 adolescent females were recruited: 25 low risk control participants who did not develop depression (control), 20 whose parents had a history of depression and developed depression themselves (i.e. converted) and 20 whose parents had a history of major depressive disorder but did not develop depression (i.e. resilient). The brains of all participants were scanned several times using resting-state fMRI (which measures brain function at rest) over several years. They compared functional connectivity (synchronous brain activity) between resilient and converted females and between resilient and control females. They assessed the functional connectivity profiles of three brain regions known to be involved in depression: the amygdala (emotion), the anterior insula (attention/cognition) and the dorsolateral prefrontal cortex (planning). They measured the relationship between functional brain connections and life events.
What did they find?
Females who were resilient to depression showed stronger functional connections in the brain between the amygdala (involved in fear and emotion) and the orbitofrontal cortex (involved in impulse control and modulating emotions). A stronger connection between these regions was associated with more positive life events. Resilient individuals also showed stronger connections between the dorsolateral prefrontal cortex (involved in planning and executive function) and the frontotemporal cortex (involved in cognitive control). Both resilient and converted groups had stronger functional connectivity within the salience network (a network of regions involved in attention and cognition) compared to the control group
What's the impact?
This is the first study to show that functional connections in the brain can be markers for resilience to depression in adolescent females at high risk for depression. Stronger functional connections could represent adaptation in the brain in response to positive life experience. It is crucial to understand how adolescents can develop resilience to depression in order to better prevent and treat depression.
A. Fischer et al., Neural Markers of Resilience in Adolescent Females at Familial Risk for Major Depressive Disorder. JAMA Psychiatry (2018). Access the original scientific publication here.