A new study published in Research on Child and Adolescent Psychopathology suggests that lower birth weight is linked to attention-deficit and aggression issues.
Low birth weight can be a risk factor for many problems, both physical and mental. Past research has regularly linked low birth weight to attention deficit hyperactivity disorder (ADHD), but research linking it to other mental health outcomes, such as OCD, autism, and depression have had less support. Past research has also shown sex differences in birth weight’s effect, with low-birth-weight boys showing higher levels of neurocognitive issues than girls. This study seeks to explore the relationship between birth weight and mental health in children who are 9-10 years old.
Study author Niamh Dooley and colleagues utilized data from the Adolescent Brain Cognitive Development study, which studied children 9-10 years old from 22 sites across the United States. Of this data, Dooley and colleagues analyzed data from 9,076 children, excluding children who were twins or triplets. In most cases, the primary respondent was the child’s mother. Researchers utilized information on birth weight, gestational age, child behavior checklist, family history of mental illness, and socioeconomic factors.
The researchers found that birth weight showed the strongest effects when it came to attention issues, including when socioeconomic factors, race, and gestational age were controlled for. Additionally, low birth weight was associated with more somatic complaints, including headaches, tiredness, nausea, and more, which has a significant effect on the child’s wellbeing.
This study did not find any significant link between birth weight and autism, which conflicts with some previous research. Additionally, this study did not find any link between birth weight and depression or thought problems, though this is possibly due to the young age of the sample. This research pointed to a higher risk of aggression and attention problems in males with low birth weights, as opposed to females with low birth rates.
This study took important strides into understanding birth weight and neurocognitive issues. Despite this, it has some limitations. One such limitation is the constrained age of the participants. Only using 9 to 10 year old participants does not allow for proper conclusions regarding mental illnesses that tend to develop later in life, such as depression or bipolar disorder. Another limitation is that this study relied heavily on parent-reported data, which is susceptible to bias.
“Our results suggest that the psychological effects of birth weight are strongest for attention problems at this age (9–10 years), rather than autistic traits,” the researchers concluded. “This contrasts with recent registry-based findings and highlights the importance of assimilating evidence from a variety of study designs to avoid sampling bias. Our data also suggests males are particularly vulnerable to the psychological effects of lower birth weight, particularly problems of attention and aggression. This, given further replication, may have strong implications for sex-specific mechanistic and prediction models.”
The study, “Birth Weight and Childhood Psychopathology in the ABCD Cohort: Association is Strongest for Attention Problems and is Moderated by Sex“, was authored by Niamh Dooley, Mary Clarke, David Cotter, and Mary Cannon.