ORIGINAL PAPER Negative Mood States or Dysfunctional Cognitions: Their Independent and Interactional Effects in Influencing Severity of Gambling Among Chinese Problem Gamblers in Hong Kong Daniel Fu Keung Wong 1 • Xiao Yu Zhuang 1 • Alun Jackson 2 • Nicki Dowling 3 • Herman Hay Ming Lo 4 Ó Springer Science+Business Media, LLC 2017 Abstract Gambling-related cognitions and negative psychological states have been pro- posed as major factors in the initiation and maintenance of problem gambling (PG). While there are a substantial number of studies supporting the role of cognitive dysfunctions in the initiation and maintenance of PG, very few empirical studies have explored the specific role of negative psychological states in influencing PG behaviours. In addition, very few studies have examined the interaction effects of cognitive dysfunctions and negative psychological states in exerting influence on PG behaviours. Therefore, the present study aims to examine the main and interaction effects of gambling-related cognitions and psychological states on the gambling severity among a group of problem gamblers in Hong Kong. A cross-sectional research design was adopted. A purposive sample of 177 problem gamblers who sought treatment from a social service organization in Hong Kong completed a battery of stan- dardised questionnaires. While gambling-related cognitions were found to exert significant effects on gambling severity, negative psychological states (i.e. stress) significantly mod- erated the relationship between gambling cognitions and gambling severity. In essence, those participants who reported a higher level of stress had more stable and serious gam- bling problems than those who reported a lower level of stress irrespective of the level of gambling-related cognitions. The findings of the moderating role of negative emotions in the relationship between cognitive distortions and severity of gambling provide insight towards developing an integrated intervention model which includes both cognitive-be- havioural and emotion regulation strategies in helping people with PG. & Daniel Fu Keung Wong dfkwong@hku.hk 1 Department of Social Work and Social Administration, The University of Hong Kong, The Jockey Club Tower, Pokfulam Road, Pokfulam, Hong Kong 2 Problem Gambling Research and Treatment Centre, University of Melbourne, Parkville, VIC 3010, Australia 3 School of Psychology, Faculty of Health, Deakin University, Burwood, VIC 3125, Australia 4 Department of Applied Social Sciences, The Hong Kong Polytechnic University, Hung Hum, Kowloon, Hong Kong 123 J Gambl Stud DOI 10.1007/s10899-017-9714-2