Background: Few studies have examined the involvement of the central dopaminergic system in the pathophysiology of mood disorders. The study of prolactin (PRL) secretion may be an informative indirect method for the assessment of the dopaminergic system in children with major depressive disorder (MDD).
Methods: Plasma PRL concentrations were measured at 20-min intervals over a 24-hr period in 40 pre-pubertal children with MDD, 18 with non-affective psychiatric disorders (PC), and 6 normal controls (NC). A subgroup of depressed children (n = 21) was restudied after recovery.
Results: There was no significant differences in either the amount or the pattern of PRL secretion between the MDD, PC, and NC groups. Children who recovered from their depression secreted less PRL during sleep and more while awake compared to when they were acutely depressed.
Conclusions: Overall, there were no differences in baseline PRL secretion between children with MDD, NC and psychiatric control. These results suggest that the dopaminergic system as measured by baseline PRL blood levels is not compromised in children with MDD.