Neural Response to Rewards, Stress and Sleep Interact to Prospectively Predict Depressive Symptoms in Adolescent Girls

Abstract

Blunted reward processing both characterizes major depressive disorder and predicts increases in depressive symptoms. However, little is known about the interaction between blunted reward processing and other risk factors in relation to increases in depressive symptoms. Stressful life events and sleep problems are prominent risk factors that contribute to the etiopathogenesis of depression and have been linked to reward dysfunction; these factors may interact with reward dysfunction to predict increased depressive symptoms. In a large sample of 8- to 14-year-old adolescent girls, the current study examined how blunted reward processing, stressful life events, and sleep problems at baseline interacted to predict increases in depressive symptoms 1 year later. Reward processing was indexed by the reward positivity (RewP), an event-related potential elicited during a simple monetary reward paradigm (i.e., Doors task). Two-way interactions confirmed that a blunted RewP predicted increased depressive symptoms at (a) high levels of stress but not average or low levels of stress, and (b) high and average levels of sleep problems but not low levels of sleep problems. Finally, a 3-way interaction confirmed that a blunted RewP predicted increased depressive symptoms at high levels of stress and sleep problems but not average or low levels of stress and sleep problems. Thus, adolescents characterized by low reward response (i.e., blunted RewP) were at an increased risk of developing depressive symptoms if they experienced increased stressful life events or sleep problems; moreover, risk was greatest among adolescents characterized by all 3.

Figure 1:

Waveform and headmap of the RewP (dashed) as well as the neural response to gains (black) and losses (gray) at electrode site FCz. The x-axis represents time in milliseconds and the y-axis represents the amplitude in microvolts (uV). The headmap represents the scalp distribution of the RewP during 100 ms interval from 250 to 350 ms following feedback (N = 183).

Figure 2:

The figure displays the predicted CDI depression scores at follow-up from the interaction between baseline RewP and ALEQ stress. Note that CDI depression scores at baseline were included as a covariate.

Figure 3:

The figure displays the predicted CDI depression scores at follow-up from the interaction between baseline RewP and PSQI sleep. Note that CDI scores at baseline were included as a covariate.

Figure 4:

The figure displays the predicted CDI depression scores at follow-up from the three-way interaction between baseline RewP, ALEQ stress score and PSQI sleep score. Note that CDI scores at baseline were included as a covariate.