We plan to adapt MARS-10 for our small scale research but finding difficulty getting permission. Copyright clearance center only allow use of original without any adaptation, not getting much response from Elsevier and author.
I think you can adapt it and use the modified version. You will still reference the original version as you would reference any other published work, and then use your own modified version. I don't think there is a need to obtain permission because you're not including the original version in your publications, and are referencing it anyway. However, the validity of your modified version will need to be established.
Asta Ratna Prajapati - Sorry to come back to you on this. Still awaiting a response from the author. Please can I ask if a license was needed for use of the tool, or just an acknowledgment in any potential publication?
Based on my understanding - If purely for research purpose acknowledgement would do but if you want to publish MARS-10 or adopted version on publication etc then formal authorisation needed.
As I have been receiving quite a lot of request for MARS-10 questionnaire and scoring here is the link to publicaly vailable image with questions, scoring & interpretation. https://binged.it/31cZV1c
Needless to say that original paper by Thompson et al (Article Reliability and validity of a new Medication Adherence Ratin...