The years of adolescence tend to present many stressful events. Not coincidentally, more than 1 in 5 youth age 9 to 17 suffer from a diagnosable mental health condition.  Extensive research shows that anxiety and depression, at any age, are strongly associated with exposure to stressful life events (SLEs). However, little is known about the specific brain mechanisms underlying this connection.

Katie McLaughlin, PhD is our 2015 One Mind / AIM Rising Star Research Award winner, and an Associate Professor of Psychology at University of Washington (now Stress & Development Lab Director at Harvard). McLaughlin’s research pursues a brilliantly direct and original approach to understanding the biology linking the stress of adolescent life with the development of anxiety and depression.

One critical challenge not met by previous studies has been in monitoring participants with sufficient frequency to document the neural changes associated with SLEs. This challenge arises from the speed of changes in the brain that, in turn, influence emotion and behavior, following stressful events. McLaughlin’s team is now analyzing these changes, as they have progressed in study participants, continuously using wearable digital technology, as well as monthly, using brain imaging and face-to-face interviews.

These precise assessments have provided the fine-resolution data that, as analysis proceeds, may reveal biological markers of adolescent anxiety and depression early enough to prevent the onset of anxiety and mood disorders.

As of May 2017, McLaughlin’s team has completed collecting the data needed for analysis. Her team’s research is proceeding quickly toward answering three critical questions:

1. How do stressful life events change the neurobiology underlying how young people respond emotionally to their environment? McLaughlin predicts that after SLEs, teens will assign greater salience to negative emotional stimuli, reflected in heightened response to these cues in the brain’s fear circuits, and reduced pleasure from positive stimuli, reflected in blunted response to positive cues in the brain’s reward circuits. She also predicts that adolescents neural circuits regulating positive and negative emotions will be weakened.
2. Are these stress-induced neurobiological changes governed by daily variations in physical activity, sleep, social behavior, and physiological arousal? She predicts that adolescents will experience reduced sleep duration and quality, reduced social engagement (as seen through the reduced frequency of phone and text use), reduced physical activity (tracked by steps), and reduced heart period variability and elevated sympathetic tone, which will mediate changes in brain function following SLEs.
3. Do these stress-induced changes in neurobiology predict symptoms of anxiety and depression? By correlating fluctuations in neural markers with changes in symptoms monthly, this connection will become clear.

McLaughlin’s team’s preliminary analysis of their data has so far confirmed their initial predictions: participants with higher average levels of stress throughout their 12 months under observation were more likely to display symptoms of depression during this period, adding evidence for a link between stress and depression. Even more usefully, during periods when specific participants stress levels were increasing, their reported depression symptoms were also observed to increase. This preliminary finding suggests that by close, smartphone-based monitoring of an adolescent patient’s stress patterns, a clinician could predict oncoming risk for depressive episodes, and intervene to prevent these, perhaps even immediately via smartphone.

As Dr. McLaughlin suggests, “Understanding these patterns will allow a precision medicine approach-where interventions are tailored to each particular person, and delivered at the precise moment they are needed to truly become possible for mental health problems.”

We at One Mind are grateful to the donors of AIM for Mental Health for enabling us to support Dr. McLaughlin as she illuminates the basis for adolescent anxiety and depression.

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