Youth with severely adverse early life histories are at double the risk of increased emotional problems as they transition from childhood into adolescence. This risk may reflect the calibration of stress-mediating systems to harsh conditions during sensitive periods early in life. Yet, not all youth with such histories are affected. The proposed study tests the novel pubertal stress recalibration hypothesis; specifically puberty opens a second sensitive period for calibration of stress-mediating systems to current life conditions at the approach of sexual maturity. For youth who experienced adverse early care, pubertal development allows a shifting of stress-system activity to that seen among youth without such histories if concurrent stressors are low and a hyper-sensitization of stress activity if current life conditions are stressful. Our target participants will be youth adopted internationally from orphanages (post-institutionalied, PI) youth, compared to youth reared in their families of origin (non-adopted,NA). We will follow 368 youth examining them annually over 3 time points (0, 1 and 2 yrs). The use of an accelerated longitudinal design (4 grps: 7-8, 9-10, 11-12, 13-14 yrs) and growth curve modeling allows examination of a broad range of the pubertal period (7 through 16 yrs). Annual measures will be made of the HPA axis (salivary cortisol), the SAM system (pre-ejection period) for PI and NA youth in relation to current life stress (Youth Life Stress Interview completed annually) and pubertal stage (annual nurse-conducted Tanner Staging). Measures of stress-mediating systems activity will be obtained using the Trier Social Stress Test for Children and home assessment of the cortisol awakening response (CAR). Our prior research with PI youth showed a normalization of the CAR by Tanner stage 3-5, compared to same aged youth at stages 1-2. This proposal is a logical extension of that work that will also test the hypothesis that shifts in stress-system activity mediates the increase in emotional problem symptoms in adolescence. The results of this study should help determine whether the peripubertal period is a critical time to intervene with children exposed to early life adversity.