DRD2 and anemia (phenotype): This may also result from impaired dopaminergic signaling, consistently reported in animal models of ID.49 Additionally, increased BG volumes in the context of altered dopaminergic signaling has been reported following exposure to psychostimulants and treatment with antipsychotic medications with potent dopamine D2 receptor antagonist activity.50,51 This association was more significant in female than male participants, again, likely reflecting differences in the age of onset of these developmental changes and duration of ID without anemia.45