Acknowledgements
The late Professor Dafydd Stephens (from the Department of Psychological Medicine and Neurology, School of Medicine, Cardiff University, UK) contributed to studies on positive experiences and initial writing of this manuscript but passed away during preparation of this manuscript. Some of the research discussed in this report has been funded by Finnish Slot Machine Association, RAY.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.