All of the following psychotropic drugs have abuse liability, EXCEPT:

Escitalopram is an SSRI and it does not cause addiction or habbit formation. Hence it does not have abuse potential. Methylphenidate is a stimulant belonging to the class of Amphetamines. It has an abuse potential and is usually a controlled drug. Buprenorphine is a semi-synthetic opiod and Dextro-propoxyphene is an analgesic of opiod category. Both the opiods have an abuse potential as they can cause drug dependence.