Preschool regulatory problems and attention-deficit/hyperactivity and cognitive deficits at school age in children born at risk: different phenotypes of dysregulation?

BACKGROUND

Early regulatory problems (RP), i.e., excessive crying, feeding, and sleeping difficulties, have been reported to be predictors of cognitive and attention-deficit/hyperactivity problems. However, previous studies had limitations such as small sample size or retrospective design.

AIM

To investigate whether persistent RP from infancy until preschool age are precursors of ADHD problems and cognitive deficits at school age.

STUDY DESIGN

A prospective study from birth to 8.5years of age.

SUBJECTS

1120 infants born at risk.

MEASURES

RP were assessed at 5months (i.e., excessive crying, feeding, and sleeping problems), 20, and 56months (i.e., eating and sleeping problems) via parent interviews and neurological examination. At 8.5years of age, IQ was assessed by a standard test (K-ABC), and ADHD problems by direct observations in the test situation and by the Mannheimer Parent Interview (MPI, DSM-IV diagnosis of ADHD).

RESULTS

23.8% of the sample born at risk had RP at least at two measurement points until preschool age. Persistent RP predicted lower IQ (β=-.17; 95% CI (-.21; -.10)), behaviour problems (β=-.10; 95% CI (-.15; -.03)), attention (OR 2.43; 95% CI (1.16; 5.09)) and hyperactivity problems (OR 3.10; 95% CI (1.29; 7.48)), and an ADHD diagnosis (OR 3.32; 95% CI (1.23; 8.98)) at school age, even when controlled for psychosocial and neurological confounders.

CONCLUSIONS

Early persistent RP increased the odds of ADHD and associated problems at school age, indicating a cascade model of development, i.e., infant behaviour problems provide the starting point of a trajectory of dysregulation through time.