Reward processing and future life stress: Stress generation pathway to depression

Area of Science:

• Neuroscience
• Psychology
• Psychiatry

Background:

• Blunted reward sensitivity and life stress are recognized depressogenic factors.
• Individuals with vulnerabilities often experience dependent life stressors, increasing depression risk.
• The role of neural vulnerability in generating life stress remains understudied.

Purpose of the Study:

• To investigate if neural reward sensitivity prospectively predicts life stress generation.
• To examine if life stress mediates the relationship between neural reward sensitivity and subsequent depression.
• To understand the neural mechanisms underlying stress generation in depression.

Main Methods:

• Assessed neural reward sensitivity using the Reward Positivity (RewP) event-related potential in 467 never-depressed adolescent girls.
• Measured dependent and independent life events via interviews over 18 months.
• Administered self-report depression symptom measures at baseline and follow-up.

Main Results:

• A blunted RewP predicted greater dependent life stress, but not independent life stress.
• Mediation analyses showed a significant indirect effect of RewP on depression through dependent life stress.
• Neural reward processing influences the generation of depressogenic life stress.

Conclusions:

• Neural sensitivity to reward plays a critical role in the prospective generation of dependent life stress.
• This neural processing is a vulnerability factor that contributes to depression risk via stress generation.
• Findings suggest targeting reward sensitivity may be a novel approach for depression prevention.