The authors identified previous reviews of programs that aimed to prevent and reduce gambling harm. The authors searched online databases for systematic reviews. They found 30 articles looking at either programs for an entire population or programs targeted to people at risk of harm. The authors noted that evidence for most programs is weak. There is a lack of evidence about whether these programs are useful over a long period of time. The authors also noted a lack of screening programs and programs to provide ongoing support for people after their treatment.