“…A number of observational studies have reported CBT to be useful for improving low mood in PD. These included uncontrolled pre‐test–post‐test designs (Berardelli, Pasquini, Bloise, et al, 2015; Dobkin, 2014; Dobkin, Allen, & Menza, 2007; Dobkin, Interian, Durland, Gara, & Menza, 2018; Dobkin, Menza, Allen, Tiu, et al, 2011; Shinmei et al, 2016), case series (Cole & Vaughan, 2005; Dobkin, Allen, & Menza, 2006; Feeney et al, 2005), and a single case study (Richardson & Marshall, 2012). Some of the improvements in mood were also maintained at 1‐month (Dobkin et al, 2006; Feeney et al, 2005) and 3‐month (Shinmei et al, 2016) follow‐ups.…”