This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).

This article has been retracted at the request of the Editor-in-Chief and Author. The authors have plagiarized part of a paper that had already appeared in Addictive Behaviors 34/3 (2009), pages 237–245, http://dx.doi.org/10.1016/j.addbeh.2008.10.016. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.