Table 1.
Overview of study characteristics
| Study | Sample | Intervention | Contrast/control | Outcome | Missing data procedure | Data available at last follow-up | |||
| Age; M (SD) | Sex (%♂) | Country | Diagnostic procedure | ||||||
| Carlbring and Smit (2008) | 31.9 (9.8) | 94% | Sweden | DSM-IV (computerized screening interview) |
I-CBT (motivational interviewing, open-ended questions evoking change and CBT-techniques based on Hodgins (2002) and Ladouceur and Lachance (2006)) N = 34; eight sessions Therapist support was provided comprised feedback on homework assignments by email and a weekly telephone call |
Waitlist
N = 32 (at post, not at follow-up) |
NODS | LOCF | 36 months |
| Casey et al. (2017) | 44.4 | 41% | Australia | DSM-IV (online checklist) |
I-CBT (increased awareness of factor related to gambling behaviour, identifying and challenging thinking errors, imaginal exposure, relaxation, problem solving, dealing with negative emotions, relapse prevention). N = 60, six sessions. I-MFS (monitor gambling behavior, feedback on progress, supportive measures). N = 59, 6 sessions. No therapist support was provided |
Waitlist
N = 55 (at post only) |
GSAS SOGS GUS GRSEQ GRCS Frequency gambling Money spent |
Multilevel modelling | None |
| Cunningham, Hodgins et al. (2019) | 40.5 | 43% | USA/Canada | PGSI≥3 (self-report) |
I-CBT (based on self-help booklets by Hodgins (2002)). N = 102, optional no. sessions I-CBT + mood gym (internet intervention for mental health distress targeting depression and anxiety) N = 112, optional number of sessions No therapist support was provided |
Not applicable | NODS Frequency gambling |
Maximum likelihood | 6 months |
| Cunningham, Godinho et al. (2019) | 36.5 (10.9) | 45% | USA/Canada | PGSI≥5 3 (self-report) |
I-CBT (based on Hodgins, Fick, Murray, and Cunningham (2013)). N = 151, optional number of sessions No therapist support was provided |
No intervention
N = 170 (at post and follow-up) |
GSAS NODS Frequency gambling |
Maximum likelihood | 6 months |
| Cunningham et al. (2020) | 39.0 | 50% | USA/Canada | PGSI≥3 (self-report) |
I-CBT (based on self-help booklets by Hodgins (2002)). N = 143, optional number of sessions I-CBT+ alcohol feedback (comparative feedback on alcohol use) N = 139, optional number of sessions No therapist support was provided |
Not applicable | NODS Frequency gambling |
Maximum likelihood | 6 months |
| Hodgins et al. (2019) | 46.7 | 53% | USA/Canada | PGSI≥3 (self-report) |
I-CBT (self-assessment activities and behavioural and cognitive strategies for reducing and quitting gambling) N = 95, optional number of sessions No therapist support was provided |
Check Your Gambling (personalized feedback on gambling and advice on how to reduce/stop) N = 92, one session (at post and follow-up) |
NODS Frequency gambling Money lost |
Maximum likelihood | 12 months |
| Jonas et al. (2020) | 33.5 (11.5) | 72% | Germany | Self-referral |
Eclectic (clarifying situation, activating resources, establishing coping resources, diary of gambling behavior, develop control strategies, enhancing quality of life, evaluating pro and cons of gambling, gaining overview on debts developing emergency kits for high-risk situations, feed on diary and exercises. N = 54, optional number of sessions Therapist support was provided and comprised a 50 min admission chat, weekly feedback on diary/exercises and a 30-min concluding chat E-mail counselling (describe gambling, impact on life, reasons for stopping, feedback on how to cope, interaction based on solution-focused approach and motivational interviewing) N = 54, optional number of sessions Therapist support was provided and comprised time-lagged message exchanges |
Waitlist
N = 57 (at post but not at follow-up) |
PGSI Frequency gambling |
Multiple imputation | 12 months |
| Luquiens et al. (2016) | 34.7 (10.1) | 92% | France | PGSI≥5 (self-report) |
E-mailed I-CBT (based on Ladouceur and Lachance (2006). N = 14, six sessions Therapist support was provided and comprised weekly emails by psychologist with personalized guidance I-CBT self-help book (based on Ladouceur and Lachance 2006) N = 44, six sessions PNT (feedback on gambling category and prevalence information of category) N = 65, one session |
Waitlist
N = 65 (at post and follow-up). |
PGSI Frequency gambling Money lost |
Completers only | 3 months |
| Nilsson et al. (2018) | 36.8 | 89% | Sweden | PGSI≥8 (self-report) |
I-CBT (strategies handling cognitions and cravings, behavioral activation and functional analysis, motivation enhancement and psychoeducation). N = 8, ten sessions I-BCT (functional analysis, behavioral activation, strategies for handling gambling cognition and psychoeducation) N = 10, ten sessions Therapist support was provided for both conditions and comprised weekly counselling for 15 min |
Not applicable | NODS Money lost |
Bayesian Markov chain Monte Carlo | 6 months |
| Nilsson et al. (2020) | 35.6 (11.8) | 82% | Sweden | PGSI≥8 (self-report) |
I-CBT (psychoeducation, behavioral analysis, motivation enhancement, behavioral activation, cognitive restructuring, goalsetting, economic recovery, communication skills training, relapse prevention, repetition) N = 68, 10 sessions I-BCT (psychoeducation, behavioral analysis, motivation enhancement, behavioral activation, cognitive restructuring, goalsetting, economic recovery, communication skills training, reinforce positive behaviors, relapse prevention, repetition) N = 68, ten sessions Therapist support was provided for both conditions, comprising weekly counselling for 15 min |
Not applicable | NODS ICS Money lost |
Intent-to-treat | 12 months |
| Rosen et al. (2020) | 32.5 | 87% | USA | PGSI≥3 (self-report) |
Brief advise intervention (feedback regarding problem gambling, risk factors for development of problems, suggested ways to reduce risk) N = 51, one session No therapist support was provided |
Referral to treatment (informed about local resources to seek help) N = 51 (at post and follow-up) | ATGS-8 Frequency gambling Money spent |
Not applicable | 1 month |
| So et al. (2020) | 36.3 | 79% | Japan | PGSI≥3 (self-report) |
I-CBT (personalized feedback, monitoring, goalsetting, message about triggers, coping with urges, message about cognitive distortion) N = 96, 28 sessions No therapist support was provided |
Assessment only
N = 101, two sessions (at post only) |
PGSI GSAS Gambling frequency |
Multiple imputation | None |
| Wittekind et al. (2019) | 35.2 | 75% | Germany | SOGS≥1 (self-report) |
Approach bias modification (push all gambling related pictures – avoidance, pull all neutral picture – approach with computer mouse) N = 66, one session No therapist support was provided |
Sham (pushing and pulling were independent of picture content) N = 65, one session (at post only) |
PG-YBOCS | Multivariate imputation by chained equations | None |
ATGS-8: Attitudes Towards Gambling Scale-8. GRCS: Gambling Related Cognitions Scale. GRSEQ: Gambling Refusal Self-Efficacy Questionnaire. GSAS: Gambling Symptom Assessment Scale. GUS: Gambling Urge Scale. I-BCT: Internet behavioral couple therapy. I-CBT: Internet cognitive behavioral therapy. I-MFS: Internet based monitoring, feedback and support. ICS: Inventory of Consequences of Gambling for the Gambler and Concerned Significant Others. LOCF: Last observation carried forward. NODS: NORC Diagnostic Screening for Gambling Disorders. PG-YBOCS: Yale Brown Obsessive Compulsive Scale adapted for pathological gambling. PGSI: Problem Gambling Severity Index. PNT: Personalized normative feedback. SOGS: South Oaks Gambling Screen.