(2023) [18] report no striatal D2R availability differences between obesity and controls for the majority of the radiotracers, namely, [11C]raclopride (2 studies included [7, 20]), [18F]fallypride (2 studies included [21, 22]) and N-[11C]methyl)benperidol ([11C]NMB) (2 studies included [23, 24]), but a significant difference was found for [123I]iodobenzamide ([123I]IBZM) (3 studies included [25–27]). Here, DRD2 is linked to obesity due to melanocortin 4 receptor deficiency.