dr clark is the director of the centre for gambling research at ubc , which is supported by funding from the province of british columbia and the british columbia lottery corporation ( bclc ) .
dr clark has provided paid consultancy to cambridge cognition ltd . on issues relating to neurocognitive assessment .
dr clark has not received any other direct or indirect payments from the gambling industry or any other groups substantially funded by gambling to conduct research or to speak at conferences or events .
 billieux et al . ( 2015 ) propose that the recent proliferation of behavioral addictions has been driven by deficiencies in the underlying research strategy . 
 this commentary considers how pathological gambling ( now termed gambling disorder ) traversed these challenges to become the first recognized behavioral addiction in the dsm-5 . 
 ironically , many similar issues continue to exist in research on gambling disorder , including question - marks over the validity of tolerance , heterogeneity in gambling motives , and the under - specification of neuroimaging biomarkers . 
 nevertheless , i contend that the case for gambling disorder as a behavioral addiction has been bolstered by the existence of clear and consistent functional impairment ( primarily in the form of debt ) , coupled with the development of a public health approach that has given emphasis to product features ( i.e. the structural characteristics of gambling forms ) as much as individual dispositions ( the  addictive personality ) . 