Can a motivational letter increase attendance to psychological treatment for gambling disorder?

High rates of treatment refusal and dropout have complicated the delivery of psychological treatment for gambling disorder, which continues accumulating evidence for efficacy. Incorporating motivational interviewing and addressing outcome expectations into psychological treatments has been shown to increase overall attendance. However, no studies have investigated whether motivational interviewing and outcome expectations can increase attendance at the initial and subsequent sessions of psychological treatment for gambling disorder. Participants were 69 prospective clients who contacted an outpatient training clinic requesting treatment services for gambling-related problems. They were randomly assigned to receive a mailed letter that incorporated principles of motivational interviewing and addressed outcome expectancies plus a telephone reminder call or to receive a telephone reminder call only. Clients who received the letter plus reminder call were more likely to attend the initial session than were clients who received the reminder call only. Clients receiving the letter were also more likely to reschedule their initial session and less likely to not show up than were clients receiving the reminder call only. There was no significant difference in attendance at subsequent sessions. These results suggest that mailing a similar letter to prospective clients of psychological treatment for gambling disorder is worthwhile, given the associated ease and low cost. Future investigations should further investigate the value of strengthening the motivation of prospective clients and clinics before initial treatment sessions, and they should investigate the distinction between clients who reschedule versus not show up. (PsycINFO Database Record (c) 2020 APA, all rights reserved).