Teenagers who seem unmoved by praise, friendship or small wins may be more vulnerable to depression when life becomes persistently stressful, new research suggests. The findings shed light on why some young people develop depressive symptoms under pressure while others remain resilient, even when facing similar levels of chronic stress.
Rates of depression in adolescents have risen sharply over the past decade, with further increases reported during and after the Covid pandemic. While exposure to stress is a well established risk factor, not every teenager experiencing family conflict, academic strain or social difficulties goes on to develop depression.
The new study, published in the Journal of Affective Disorders, examined whether differences in how teenagers’ brains respond to rewards might help explain this gap. Researchers recruited 165 adolescents aged 14–17, including young people with current depression and others considered at higher risk due to maternal history.
Participants completed two computer based tasks while their brain activity was recorded using electroencephalography. One task involved guessing games with small monetary gains and losses. The other simulated peer interactions, in which teenagers believed they were being accepted or rejected by other young people.
The team focused on a well established brain signal known as the reward positivity, which reflects how strongly the brain responds to positive feedback. A blunted response has previously been linked to depression, particularly in studies using monetary rewards.
Teenagers also underwent a detailed interview assessing chronic stress over the previous six months, including pressures related to school, friendships, romantic relationships and family life. They then reported their recent depressive symptoms.
The results showed a clear pattern. Chronic stress was strongly associated with higher depressive symptoms. But this link was significantly stronger in adolescents whose brains showed a reduced response to reward.
This effect was observed for both monetary rewards and social acceptance. In other words, teenagers who showed a muted brain response to winning money or to being accepted by peers were more likely to report depressive symptoms when they were also experiencing ongoing stress.
When both types of reward processing were analysed together, social reward sensitivity appeared particularly important. The interaction between chronic stress and reduced brain response to peer acceptance remained significant, even after accounting for monetary reward responses.
The findings are especially relevant during adolescence, a period when peer relationships and social approval become more central. If a young person derives less emotional benefit from positive social feedback, they may struggle to buffer the effects of stress in their daily lives.
Importantly, the study does not prove that reduced reward responsiveness causes depression. It is possible that chronic stress dampens the brain’s reward system, or that low reward sensitivity acts as a pre existing vulnerability. Longitudinal research will be needed to clarify direction of effect.
Still, the work adds weight to the idea that depression in teenagers is shaped by an interplay between environmental stress and individual neurobiological differences. It also suggests that focusing solely on academic pressure or family adversity may miss a crucial part of the picture.
Understanding how young people process both monetary and social rewards could help refine early identification of those at risk of anxiety and depression. It may also inform psychological interventions aimed at strengthening engagement with positive experiences, particularly in social contexts.
Teenagers with low social reward sensitivity may be more likely to develop depression under chronic stress.