The effects of the COVID-19 pandemic on neurobiological functioning in adolescents.

The COVID-19 pandemic and its associated lockdowns were an unprecedented source of stress, with striking adverse effects on adolescents' mental health but relatively unknown effects on important aspects of neurobiological functioning. Using data from 154 adolescents (age M ± SD = 16.2 ± 1.1 years; range = 13.9-19.4) drawn from an ongoing longitudinal study and assessed either before or after the pandemic, we compared the pre-pandemic and post-pandemic groups on three key stress-sensitive biological systems: the hypothalamic-pituitary-adrenal (HPA) axis, immune response, and neural responses to affective stimuli. We found that compared to those assessed before the pandemic, adolescents assessed post-lockdown had significantly lower total cortisol production, elevated levels of systemic inflammation, and reduced neural activation in the prefrontal cortex during affective processing (pseudo-F(1,3250) = 7.43, p = 0.006). These findings suggest that, for adolescents, the experience of the pandemic was associated with significant disruptions in multiple biological systems that are sensitive to stress that might have enduring adverse developmental effects.