Relative Age and Psychotropic Drug Use in Preterm and Term-Born Children and Young Adults

Abstract

BACKGROUND AND OBJECTIVES: Being among the youngest within a school class is linked to disadvantages in various educational and mental health domains. This study aimed to investigate whether preterm born infants are particularly vulnerable to relative age effects on mental health, not previously studied. METHODS: We used registry data on all Norwegians born between 1989 and 1998 to compare prescription status for psychostimulants, antidepressants, hypnotics, anxiolytics, and antipsychotics per year from age 10 to 23 years (2004-2016) between exposure groups with different time of birth in the year (relative age) and different gestational age (preterm versus term). RESULTS: Of 488 470 individuals, 29 657 (6,1%) were born preterm. For term born in November/December, the adjusted odds ratio (aORs) for psychostimulant prescription compared with peers born in January/February was 1.80 (95% confidence interval [CI], 1.69–1.91) at ages 10 to 14 years, and 1.17 (95% CI, 1.08-1.27) at ages 20 to 23 years. Within preterm born, the corresponding results were 1.39 (95% CI, 1.13-1.69) and 1.34 (95% CI, 1,00–1.78) at ages 10 through 14 and 20 through 23 years, respectively. CONCLUSIONS: Being relatively young within the school group was associated with increased psychostimulant prescription in the preterm as well as the term population. In contrast to term peers, the relative age effect for psychostimulant prescription seemed to persist to young adulthood for the preterm population. The results suggest that preterm individuals are vulnerable to long-term effects of relative immaturity and that they require careful consideration from both health care professionals and the school system.

The QTc-Bazett Interval in Former Very Preterm Infants in Adolescence and Young Adulthood is Not Different from Term-Born Controls

“…Our main motivation was driven by targeted or precision pharmacovigilance, as certain QT-prolonging drugs, such as antipsychotics or drugs used to treat ADHD, are more commonly prescribed in former preterm subjects [ 10 , 11 ]. As these drugs are associated with prolongation of the QT c-Bazett interval, the absence of any a priori prolongation in former ELBW and/or preterm subjects matters.…”

“…On the contrary, neither Gervais et al (Canada) nor Salaets et al (Belgium) confirmed these differences in former preterm subjects in young adulthood and late childhood to adolescence, respectively [ 8 , 9 ]. More clarity on the presence or absence of a difference in QT c-Bazett is relevant for precision pharmacovigilance, as certain QTc-prolonging drugs, such as antipsychotics or attention deficit and hyperactivity disorder (ADHD) drugs, are more commonly prescribed in former premature infants [ 10 , 11 ].…”