“…Thirteen studies explored the link between hallucinations and sleep disturbances in healthy populations including: self-reported insomnia (k=5; Koyanagi & Stickley, 2015;Ohayon, 2000;Sheaves et al, 2016;Sheaves et al, 2016b;Taylor et al, 2015); experimentally manipulated sleep deprivation (k=6; Giesbrecht et al, 2007;Hurdiel et al, 2014;Petrovsky et al, 2014;Meyhofer et al, 2017;2017bReeve et al, 2017; nightmare frequency (k=2; Rek et al, 2017;Sheaves et al, 2016); nightmare distress (k=2; Rek et al, 2017;Sheaves et al, 2016), chronotype (k=1; Sheaves et al, 2016); and one study improved sleep in a large randomised controlled trial (k=1; Freeman et al, 2017). One study was longitudinal (k=1; Sheaves et al, 2016b), four studies experimentally manipulated sleep (k=4; Freeman et al, 2017;Giesbrecht et al, 2007;Hurdiel et al, 2014;Reeve et al, 2017), six were cross-sectional (k=6; Barnes et al, 2011;Koyanagi & Stickley, 2015;Rek et al, 2017;Sheaves et al, 2016;2016b;Taylor et al, 2015), and one used a sleep intervention .…”