The Collaborative International Dictionary of English v.0.48:

mind-bending \mind-bending\ adj.
   intensely affecting the mind, especially in producing
   hallucinations; -- usually of chemical substances. [informal]

   Syn: mind-blowing.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

mind-bending
    adj 1: intensely affecting the mind especially in producing
           hallucinations [syn: mind-bending, mind-blowing]