IP No. 595545 The present disclosure relates to methods of treating or preventing addiction and relapse use of addictive agents, and treating or preventing addictive or compulsive behaviour and relapse practice of an addictive behaviour or compulsion, by administering a peroxisome proliferator-activated receptor gamma (PPAR ) agonist in combination with another therapeutic agent, specifically an opioid agonist or nicotine. The present disclosure also includes pharmaceutical compositions for treating or preventing addiction or relapse that include a PPAR agonist and one or more other therapeutic or addictive agents, as well as unit dosage forms of such pharmaceutical compositions, which contain a dosage effective in treating or preventing addiction or relapse. The methods and compositions of the disclosure are useful in the treatment or prevention of addiction to any agent, including alcohol, nicotine, marijuana, cocaine, and amphetamines, as well as compulsive and addictive behaviours, including pathological gambling and pathological overeating.