The instruments most recently evaluated [9,15] assess cannabis-related problems namely social or health problems (CAST) and in addition motivational aspects of cannabis use (CUDIT). The psychometric properties of the CAST are comparable to the SDS, while the performance of the CUDIT is moderate. In particular, two items – cannabis related injury (item 9) and usual hours being stoned (item 2) – performed very weakly in tests of reliability and construct validity. These questions need to be revised or deleted from the scale especially as there are hardly positive responses in the samples studied.
