Background: In ICD(International Classification of Diseases)-11 the criteria for the diagnosis of substance dependence have been revised.

Objective: Discussion of the advantages and disadvantages of the revised diagnostic criteria.

Material and methods: Discussion of criteria with respect to neurobiological, social and clinical research.

Results: In the new ICD-11, harmful drug use and substance dependence remain separate diagnostic categories. Regarding substance dependence, the former six diagnostic criteria are condensed into three pairs, two of which must be fulfilled to diagnose this disorder. Within the pairs, one affirmed symptom or aspect is sufficient for the new criterion to be fulfilled. With reference to scientific findings in the field of addiction, this appears to provide advantages as well as disadvantages. The specificity of the diagnosis of substance dependence might get worse compared to ICD-10, because only one symptom of the syndrome pairs has to be fulfilled in each newly constructed pair in order to fulfill the criterion. Therefore, the risk of false positive diagnosis of substance dependence could increase. This is a potential reason for concern because the definition of ICD-10 "persisting substance use despite clear evidence of overtly harmful consequences", is more broadly reworded in ICD-11 as "substance use often continues despite the occurrence of problems". This criterion may hence simply be fulfilled because a substance is illegal in a certain country. In the largest multinational study in 10 countries concerning concordance of diagnostic systems, alcohol dependence was diagnosed approximately 10% more often using ICD-11 compared to ICD-10.

Conclusion: In ICD-11 the well-established distinction between substance dependence and harmful drug use is preserved. Systematic studies are required to assess whether the new diagnostic criteria are clinically helpful or increase social problems by increasing false positive diagnoses of addiction.