Table 1.

Reviewed studies (N=26).

ID	Reference	Design*	Recruitment	Inclusion criteria	Participants	Comparison Arms (Interventions)	Mode of Intervention	Outcomes	Results
A	Carlbring et al. 2009 [33] Linkoping, Sweden	RCT	Sought treatment at dependency clinic	• Met one or more DSM-IV criteria for pathological gambling	• 150 self- recruited patients at an outpatient dependency clinic	MI CBT Waitlist control	Individual and group	# DSM-IV criteria for PG Gambling behavior Depression and anxiety scales Number of drinks per gambling day Intoxicated gambling days	Superiority in some areas over the no-treatment control in the short term No differences were found between MI and CBT Both MI and CBGT produced significant within-group decreases
B	Carlbring & Smit 2008 [34] Linkoping, Sweden	RCT	Media ads	18 years of age or older DSM-IV criteria for pathological gambling Live in Sweden Gambled in the past 30 days	• 66 self- selected pathological gamblers from the community	CBT Waitlist control	Internet, telephone, and email	# DSM-IV criteria for PG Depression and anxiety scales Quality of life scales	• Internet-based intervention resulted in favorable changes in pathological gambling, anxiety, depression, and quality of life compared to control
C	Cunningham et al. 2009 [35] Alberta, Canada	RCT	Recruited from previous study	• Five or more DSM-IV criteria met for pathological gambling	• 61 self- selected pathological gamblers from the community	Personalized feedback summary Waitlist control	Internet and self- help materials	Gambling behavior CPGI	• Respondents in the feedback condition displayed some evidence that they were spending less money on gambling than those in the control condition
D	Diskin & Hodgins 2009 [36] Alberta, Canada	RCT	Media ads	18 years of age or older Scoring a 3 or greater on the CPGI Not in treatment for problem gambling Gambled in the past 2 months Willing to provide collateral informant	• 81 self- selected gamblers from the community	MI Control interview	Individual	Gambling behavior Number of SOGS items satisfied # DSM-IV criteria for PG CPGI	At 12 months post-intervention participants in the MI condition spent significantly less money on gambling per month, gambled fewer days per month, and reported less distress than participants in the control condition Participants in both conditions showed overall reduction in gambling problem severity
E	Doiron & Nicki 2007 [37] Prince Edward Island, Canada	RCT	Ads in media and at gambling venues	Scored as 3-7 on the CPGI Played Video lottery terminals during the last month	• 40 self- selected video lottery terminal gamblers in the community	Cognitive restructuring and problem solving skills Waitlist control	Group	Gambling behavior Cognitive distortions related to gambling Social problem solving skills CPGI	• The experimental group endorsed fewer gambling-related cognitive distortions, engaged in less video lottery terminal gambling, and had lower scores on CPGI
F	Downling et al. 2007 [38] Victoria, Australia	RCT	Media ads	DSM-IV criteria for pathological gambling Female Preference for gaming machines	• 56 self- selected female community members	CBT Waitlist control	Group and Individual	Gambling behavior Depression, anxiety, and self-esteem measures	Individual and group treatments produced comparable outcomes Group treatment failed to produce superior outcomes to the control group in relation to several measures of psychological functioning Fewer gamblers allocated to individual treatment compared to group treatment satisfied the diagnostic criteria for pathological gambling post-treatment
G	Downling et al. 2006 [39] Victoria, Australia	n-RCT	Media ads	DSM-IV criteria for pathological gambling Female Preference for gaming machines	19 females presenting for pathological gambling treatment who preferred gaming machines	CBT Waitlist	Individual	Gambling behavior Depression, anxiety, and self-esteem measures	• The CBT group showed significant improvement on gambling behavior and psychological functioning compared to control
H	Echeburua et al. 2000 [40] San Sebastian, Spain	n-RCT	Sought treatment at gambling center	DSM-IV criteria for pathological gambling 7 or more on the Spanish SOGS Gamble mainly with slot machines	69 patients post- treatment for slot-machine preferred gambling problems	CBT post treatment Control – no post treatment	Group and individual	Abstinence Depression, anxiety, inadaptation scales Gambling behavior Family assessment	• Abstinence success higher in both individual and group treatments compared to the control group
I	Grant et al. 2009 [41] Minnesota, US	RCT	?	Aged 18 to 75 DSM-IV criteria for pathological gambling Gambled at least once per week for the past 2 months	68 individuals	Imaginal desensitisation plus MI GA	Group	Yale–Brown Obsessive Compulsive Scale Modified for Pathological Gambling Gambling Symptom Assessment Scale Clinical Global Impression – Severity Scale Depression and anxiety scales	IDMI group had significantly greater reductions inYale–Brown Obsessive Compulsive Scale Modified for Pathological Gambling total scores, gambling urges and gambling behavior People who failed to respond to GA reported significantly greater reduction in pathological gambling symptoms following later assignment to treatment arm
J	Hodgins et al. 2009 [42] Alberta, canada	RCT	Media ads	18 years of age or older Perception of a gambling problem 3 or greater on the CPGI Gambled in the past month Not involved in treatment at present Willingness to read a short book Willing to provide the name of a collateral source	• 314 self- selected gamblers from the community	MI (brief) MI with six booster sessions Mailed self-help workbook Waitlist control	Telephone and mail	# DSM-IV criteria for PG Gambling behavior Self efficacy scale	MI and MI plus booster treatment participants reported less gambling at 6 weeks than those assigned to the control groups The workbook only participants were as likely to have significantly reduced their losses over the year and to have not met criteria for pathological gambling. Participants in the brief booster treatment group showed no greater improvement than brief treatment participants
K	Hodgins et al. 2007 [43] Alberta, Canada	RCT	Media ads	18 years of age or older DSM-IV criteria for pathological gambling A goal of abstinence No gambling for a minimum of 2 weeks Not in treatment for gambling or in GA Willingness to read short booklets Willingness to provide collateral sources	• 169 self- selected pathological gamblers from the community	Single mailing of self-help workbook 8 mailings of self-help workbook	Telephone and mail	# DSM-IV criteria for PG Gambling behavior SOGS Self efficacy scales Motivation scales Depression measure	• Participants receiving the repeated mailings were more likely to meet their goal, but they did not differ from participants receiving the single mailing in frequency of gambling or extent of gambling osses.
L	Hodgins et al. 2004 [44] Alberta, Canada	RCT	Media ads	18 years of age or older Perception of a gambling problem Not involved in treatment at present for gambling	• 102 self- selected gamblers from the community	MI and self-help workbook Self-help workbook	Telephone and mail	Gambling behavior SOGS	At 24 months, the 2 groups did not differ in the number of participants reporting 6 months of abstinence The motivational intervention group gambled fewer days, lost less money, and had lower SOGS scores. Participants who received a MI and a self-help workbook in the mail, but not those who received the workbook only, had better outcomes than participants in a 1-month waiting-list control.
M	Hodgins et al. 2001 [45] Alberta, Canada	RCT	Media ads	18 years of age or older Perception of a gambling problem Not involved in treatment at present for gambling	• 102 self- selected gamblers from the community	MI and self-help workbook Self-help workbook	Telephone and mail	Gambling behavior SOGS	Participants who received the MI and workbook showed better outcomes than those receiving the workbook only at 3- and 6-month follow-ups. At the 12-month follow-up, the advantage of the MI and workbook condition was found only for participants with less severe gambling problems
N	Korman et al. 2008 [46] BC, Canada	RCT	Referred and Media Ads	• Seeking treatment for gambling and anger problems	• 42 self- selected gamblers with anger problems from the community	Integrated anger, gambling, substance abuse treatment Only gambling and substance abuse treatment	Individual	Gambling behavior CPGI Substance use Anger measure	• Relative to the control, participants in the integrated anger and addictions treatment reported significantly less gambling and less trait anger and substance use post-treatment
O	Ladouceur et al. 2003 [47] Québec, Canada	RCT	Referred and sought treatment	• DSM-IV criteria for pathological gambling	• 58 self- selected pathological gamblers who sought	CBT Waitlist control	Group	# DSM-IV criteria for PG Perception of control Desire to gamble Self-efficacy perception Abstinence	Significantly more gamblers in the treatment group did not meet DSM-IV criteria for pathological gambling compared to control Beneficial outcomes in all measures and were maintained at 6-, 12- and 24 month follow-up compared to control
P	Ladouceur et al. 2001 [48] Québec, Canada	RCT	Referred and sought treatment	• DSM-IV criteria for pathological gambling	• 66 self- selected pathological gamblers who sought treatment at treatment center	CBT Waitlist control	Individual	# DSM-IV criteria for PG Gambling behavior SOGS Perception of control Desire to gamble Self-efficacy perception	• Significant changes in the treatment group on all outcome measures and maintenance of therapeutic gains at 6- and 12- mont
Q	Marceaux & Melville 2011 [49] LA, US	RCT	Media ads	21 years of age or older DSM-IV criteria for pathological gambling	• 49 self- selected pathological gamblers from the community	Node-link mapping-enhanced CBT 12-step Waitlist control	Group	Gambling behavior # DSM-IV criteria for PG Perception of control Self-efficacy perception Desire to gamble	Compared to the control, both treatment groups resulted in significant improvements in many measures No difference was found between the two treatment groups
R	Melville et al. 2004 [50] LA, US	RCT	Media ads	DSM-IV criteria for pathological gambling 5 or more on SOGS	• 20 self- selected pathological gamblers from the community	Node-link mapping-enhanced CBT Non-mapping CBT Waitlist control	Group	Gambling behavior # DSM-IV criteria for PG Ability to control Ability to refrain Desire to gamble Depression and anxiety measures	The node-link-mapping-enhanced group treatment produced improvements in more of the dependent measures of pathological gambling than treatment without maps or an equivalent-length waiting period Depression and anxiety scores were lower post-treatment in the treatment group compared to the control
S	Milton et al. 2002 [51] N.S.W., Australia	RCT	Media ads and referred	• DSM-IV criteria for pathological gambling	• 47 pathological gamblers presenting at a University- based gambling treatment clinic	CBT CBT and compliance improving techniques	Individual	Gambling behavior SOGS # DSM-IV criteria for PG Retention rates	Compliance-improving interventions significantly reduced dropout rates At 9-month follow-up, there was no difference in outcome between treatments, although both produced clinically significant change
T	Myrseth et al. 2009 [52] Bergen, Norway	RCT	Sought treatment	DSM-IV criteria for pathological gambling 5 or more on SOGS 18 years of age or older	• 14 gamblers self-selected gamblers seeking treatment at the university clinic	CBT Waitlist control	Group	# DSM-IV criteria for PG Gamblers inventory of negative consequences	The treatment group improved on the DSM-IV Criteria for Pathological Gambling, but did not show a significant reduction in gambling money spent Both groups at 3-months follow-up, had a significant improvement on all three variables from pre-treatment to follow-up.
U	Oei et al. 2010 [53] Brisbane, Australia	RCT	?	?	• 102 self- selected community members	CBT group CBT individual Waitlist control	Group and Individual	Gambling behavior Gambling cognitions Gambling urges Life satisfaction Psychological states	At post-treatment, there were significant improvements in all dependent variables for both treatment conditions but not for the waitlist condition Individuals that completed the individual (compared to group) treatment condition generally had higher effect sizes for gambling correlates
V	Petry et al. 2009 [54] Connecticut, US	RCT	Via screening efforts and flyers posted on campuses	18 years of age or older Endorse 3 items on the SOGS Spent a minimum of $100 on gambling Gambled at least four times in the past two months	• 117 self- selected college student gamblers	Assessment only Brief advice MET MET plus CBT	Individual	Gambling behavior ASI- Gambling score	Compared to the assessment-only condition, those receiving any intervention had significant decreases in ASI-G scores and days and dollars wagered over time The MET condition significantly decreased ASI-G scores and dollars wagered over time, and it increased the odds of a clinically significant reduction in gambling at the 9-month follow-up relative to the assessment only condition
W	Petry et al. 2008 [55] Connecticut, US	RCT	Screening at substance abuse and medical clinics	18 years of age or older Endorse 3 items on the SOGS Spent a minimum of $100 on gambling Gambled at least four times in the past two months	• 180 self- selected gamblers from substance abuse and medical clinics	Assessment only Brief advice MET MET plus CBT	Individual	Gambling behavior SOGS ASI- Gambling score	Relative to assessment only, brief advice was the only condition that significantly decreased gambling between baseline and week 6, and it was associated with clinically significant reductions at month 9 Between week 6 and month 9, MET+CBT evidenced significantly reduced gambling on one index compared to the control condition
X	Petry et al. 2006 [56] Connecticut, US	RCT	Media ads	DSM-IV criteria for pathological gambling 18 years of age or older Had gambled in past two months Fifth grade reading level	• 231 self- selected pathological gamblers from the community	GA referral + CBT workbook GA referral plus CBT therapy Referral to GA	Individual	Gambling behavior SOGS ASI- Gambling score	CBT group reduced gambling relative to GA referral alone during the treatment period and resulted in clinically significant improvements, with some effects maintained throughout follow-up Individual CB therapy improved some outcomes compared with the CB workbook
Y	Toneatto & Dragonetti 2009 [57] Ontario, Canada	RCT	Media ads	One or more DSM-IV criteria met for pathological gambling Gambled within the past month Not involved in treatment at present for gambling	• 99 self- selected pathological gamblers from the community	Cognitive therapy Behavior therapy Motivational therapy Minimal intervention	Individual	Gambling behavior # DSM-IV criteria for PG Abstinence Cognitive distortions	• A cognitive approach did not yield superior outcomes than did treatments that did not explicitly address cognitive distortions
Z	Toneatto & Dragonetti 2008 [58] Ontario, Canada	RCT	Ads in media and at mental health agencies	Self-report of a gambling problem Seeking out-patient treatment for gambling problem	• 126 self- selected problem gamblers from the community	CBT 12-Step	Group	Gambling behavior abstinence	12- month post-treatment showed no group differences on key gambling variables Participants who attended more sessions and chose an initial abstinent treatment goal appeared to achieve better outcomes

^*We accepted the authors’ description of their research design

Abbreviations: CBT: Cognitive Behavioral Therapy; MI: Motivational Interviewing ; MET: Motivational Enhancement Therapy Gambling behavior: (e.g. days gambled, duration gambled, dollars gambled) SOGS: South Oaks Gambling Screen; CPGI: Canadian Problem Gambling Index; GA: Gamblers anonymous ASI: Addiction Severity Index RCT: Randomized Control Trial n-RCT: Non-randomized Control Trial