Why Doesn’t The Brain of Adolescents With Depression Get Used to Rejection?
Why doesn’t the brain “get used to” rejection? Researchers have discovered that adolescent girls with depression show a different response in a brain region linked to the alarm system. Even after repeated experiences of potential rejection, their brains seem to have more difficulty dampening this reaction.
For an adolescent, being accepted or rejected by peers can carry enormous weight. Typically, when a threatening situation recurs, the brain learns that it is predictable and gradually reduces its reaction. This process is known as habituation, it is as if the brain realizes it does not need to remain on high alert when faced with something it already recognizes. A new study investigated whether this adaptation occurs in the same way in adolescent girls with depression.
The researchers were particularly interested in the amygdala, a region that helps the brain identify potential threats, and the insula, which is involved in perceiving bodily sensations and processing emotionally significant situations.
To investigate how these brain areas reacted to rejection, 76 girls between the ages of 10 and 17 participated in the study: 22 had depression, 30 did not have depression but had a family history of the condition, and 24 had neither depression nor a family history.
During the experiment, the girls believed they were participating in a virtual chat room with other adolescents. Some of the virtual peers were presented as “kind”, more likely to accept them, while others were “mean”, more likely to reject them.
This scenario was repeated several times while the participants’ brain activity was recorded using functional magnetic resonance imaging (fMRI). This allowed the researchers to observe whether the brain’s response to the expectation of rejection diminished as the experience was repeated.
In girls without depression, activity in the amygdala gradually decreased when they expected to be rejected by the “mean” peers. This suggests that the brain was learning through repetition: after experiencing the same situation multiple times, the threat became more predictable, and the brain’s alarm system no longer needed to react with such intensity. A similar, though less pronounced, reduction was also observed when the girls expected positive responses from the “kind” peers.
The main difference appeared in girls with depression. The right amygdala also reacted to the expectation of rejection, but its activity decreased less over the course of repeated exposures. In other words, the brain seemed to have more difficulty becoming accustomed to the social threat.
This does not simply mean that the amygdala in these girls was always more active; what was notable was that its response did not diminish in the same way with repetition. This suggests that depression may be linked not only to a more intense emotional reaction but also to a difficulty in the brain’s ability to learn from repeated social experiences.
Interestingly, girls who did not have depression but had a family history of the condition showed a pattern of habituation similar to that of girls with no such family history. This indicates that, in this study, merely having a higher familial risk was not enough to produce the alteration observed in adolescents who already had depression.
However, since the study examined the participants at a single point in time, it is not possible to determine whether this difficulty with habituation contributes to the development of depression or arises as a consequence of it.
The findings help explain why situations involving rejection may remain emotionally draining for some adolescents with depression. If the brain struggles to recognize that a social threat has become predictable, and that it can therefore lower its state of alert, each new situation may continue to feel significant or threatening.
Understanding this altered form of social learning could, in the future, help in developing strategies to teach the brain to respond differently to social experiences and to recognize that not every potential instance of rejection constitutes a threat.
READ MORE:
Reduced amygdala habituation to anticipated social rejection in youth with major depressive disorder
M. Morningstar, M.N.K. Gravelle, D.P. Dickstein, J.S. Silk, R.E. Dahl, E.E. Nelson, D. Yee, and L.R. Stroud
Journal of Affective Disorders, Volume 403, 15 June 2026, 121380
Abstract:
In addition to its risks for morbidity and mortality, adolescent-onset depression is considered a chronic threat to youth's socioemotional development due to its potential disruption of social learning processes. Prior work has determined that youth with depression, or at-risk of developing depression due to familial history, show atypical neural responses to social feedback by peers. To better understand whether adolescents at varying levels of risk for depression show differential neural indices of social learning, the current study interrogated trial-by-trial patterns of youth's neural habituation to repeated social feedback. Seventy-six 10- to 17-year-old girls (22 diagnosed with major depressive disorder [MDD], 30 at familial risk but without MDD, 24 without MDD or familial risk) completed a chatroom task in which they repeatedly anticipated being accepted or rejected by “mean” (likely to reject) and “nice” (likely to accept) virtual peer confederates. Beta-series analyses revealed that the bilateral amygdala showed evidence of habituation to repeated social threat by the “mean” peer across groups. However, girls with MDD showed attenuated habituation in the right amygdala when anticipating feedback from the “mean” peers. Amygdala habituation was present (though attenuated) when anticipating social feedback from the “nice” peers, but did not vary by depression group. Findings identify a failure to habituate to anticipated social threat in MDD, suggesting altered social learning at the neural level. Attending to the dynamics of changing neural responses to anticipated social feedback may provide deeper insights into alterations in social and affective learning processes relevant to developing depression in adolescence.
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