Not enough published research! What does that mean?

Discrimination against people with addictive disorders is well known. Research in addictions is not immune to discrimination. A survey of six general psychiatry journals over the period of 2000‐2005 showed that some journals persistently published fewer research reports on additive disorders than others. This has further impact on literature review and also the status held about this addiction within psychiatry. Publication bias reduces the likelihood of funding for researchers of addictive disorders.