Cocaine, tobacco prenatally linked to teen impulsivity

US researchers analysed the MRI scans of 40 teenagers aged 13–15 who had experienced cocaine and/or tobacco exposure in utero.

They found adolescents exposed to either substance in utero had a larger thalamus – which is associated with behavioural impulsivity – than adolescents whose mothers were drug-free in pregnancy. 

“The association between thalamic volume and impulsivity can suggest one liability for compromised top-down control over impulsivity,” the authors wrote.

JAMA Pediatr 2013; online Feb 11