This invention relates to 1-diphenylmethyl-pyrazole derivatives of formula (I): ##STR1##

and pharmaceutically acceptable salts thereof; wherein R¹, R², R³, R⁴ and R⁵ are defined herein, as ligands for opioid receptors, particularly the delta opioid receptor. The compounds of the invention have a broad range of therapeutic uses in the area of addictions, analgesia, immunotherapy, shock and brain injuries, neurological dysfunction, gastrointestinal dysfunction, among others.