Virginia Tech researchers surveyed 350 people and found painkillers followed by opioids like fentanyl required the most attempts to quit.
Read more: https://www.dailymail.co.uk/health/article-14334309/most-addictive-drugs-ranked-study-alcohol-nicotine-opioids.html?ns_mchannel=rss&ns_campaign=1490&ito=1490