OXT and Prader-Willi syndrome: Individuals with PWS have fewer oxytocin neurons in the paraventricular nucleus of the hypothalamus, and studies have shown elevated oxytocin plasma and cerebrospinal fluids levels (Johnson, Manzardo, Miller, Driscoll, & Butler, 2016; Martin et al., 1998; Swaab, Purba, & Hofman, 1995).