Schools are central places for adolescent social lives, which is a major factor greatly affecting adolescent mental health; school climate (i.e. quality of the school social environments) can be a proximal social determinant for adolescent mental health. Supportive school environments may serve as a protective factor during crises like COVID-19, which disrupt social lives and worsen adolescent mental health. This is the first study examining whether the pandemic effects differed based on the levels of school climate on depressive symptoms (DS) and psychotic experiences (PEs) among adolescents.

School climate (score range: 0–28), DS (0–26), and PEs (0–5) were self-reported in a population-based cohort (Tokyo Teen Cohort; N = 3171) at four timepoints (10y, 12y, 14y, and 16y) before and during COVID-19. COVID-19 occurred midway through the 16y survey, allowing us to examine its impact and interaction effect with school climate while accounting for within-person changes over time using mixed-effects models.

Significant interaction effects were found on DS (unstandardized coefficient [B] = −0.166, 95% confidence interval [CI] −0.225 to −0.107) and PEs (B = −0.020, 95% CI −0.028 to −0.012). The pandemic effects were not significant for adolescents with high school climate scores (around the 80th percentile or higher), although the pandemic significantly worsened these outcomes among the overall sample.

The negative mental health effects of the pandemic were significantly mitigated among adolescents experiencing a supportive school climate. A positive school climate can protect adolescent mental health during challenging social conditions, such as pandemics.

Little is known about physical constitution outcomes for very preterm infants. Here, we compare z-scores of anthropometric parameters up to 6 years of age in children born with very low birth weight (VLBW) at less than 30 weeks of gestation, with or without intrauterine growth restriction (IUGR).

Participants were divided into four subgroups: male (M), small for gestational age (SGA) (n = 30); M, appropriate for gestational age (AGA) (n = 59); female (F), SGA (n = 24); and F, AGA (n = 61). z-Scores of body weight (BW), body length (BL), and body mass index (BMI) were assessed at birth, 1 year corrected age, 3 years of age, and 6 years of age.

For boys, BW and BMI were significantly lower among SGA children than among AGA children at all assessments, but there was no difference in BL at 3 or 6 years. For girls, BW and BL were significantly lower among SGA children than among AGA children at all assessments, but no difference was detected in BMI after 1.5 years. No significant variation in the z-score of BW or BMI in either SGA group was observed after 1 year. BL z-score in all groups gradually increased until 6 years of age.

IUGR affects BW and BMI in boys and BW and BL in girls during the first 6 years in VLBW children born at less than 30 weeks of gestation. SGA children did not catch up in BW or BMI from 1 to 6 years of age.