To study the implications of proposed changes in guidelines in ICD-11 in Alcohol and Opioid Use Disorder patients. To evaluate the concordance of ICD-11 with ICD-10 and DSM-5. To compare endorsement of various criteria for dependence between ICD 11 and other systems. To examine the agreement between ICD-11 and other systems with regard to the severity of dependence. To compare the application of WHO ASSIST in screening across systems.

A cross-sectional study among newly registered, adult male patients attending NDDTC OPD, or community clinics and using the substance in the last week. N = 200 (100 each of Alcohol and opioids). Instruments: Semi-structured proforma, CIDI 3, ASI-lite, WHO-ASSIST, AUDIT. Items of CIDI were used to make the diagnosis according to various systems. The diagnostic agreement was assessed by Kappa. Endorsement frequencies of the criteria were compared across diagnostic systems. Scores of scales across systems were compared using Two Independent sample t-test.

The highest prevalence of Dependence was found using ICD-11. Almost perfect agreement between ICD-11 and ICD-10 for both Use Disorder and Dependence for all substances (kappa >0.8) except Inhalants. Agreement for AUD, CUD, and IUD between ICD-11 and DSM-5 was substantial but less than almost perfect. Similar findings for ICD-11 Dependence and DSM-5 Moderate-Severe Use Disorder in Benzodiazepines and Inhalants (kappa ranging from 0.693–0.790). High endorsement frequencies of Salience for Alcohol and Opioids, and Craving and Tolerance for all substances (ICD Dependence); Inability to cut down or control, Craving, and Tolerance (DSM-5 UD). Mean scores of AUDIT and ASSIST were generally lower in participants who received the diagnosis according to ICD-11 (sig. difference for CUD and Cannabis Dependence).

There are significant implications of the changes in ICD-11, and further testing of the impact of these changes needs to be done.