Alcohol causes the most damage overall. It harms nearly every organ system via toxicity, leading to liver cirrhosis, multiple cancers, heart disease, brain impairment, and high mortality risk even at moderate levels. Ranking worst to least: 1. Alcohol 2. Cigarette 3. Painkillers 4. Cannabis joint 5. Energy drink Cigarettes drive cancer, COPD, and CVD through carcinogens and toxins. Painkillers risk liver/kidney damage or overdose (especially opioids). Cannabis mainly affects lungs if smoked with lower lethality. Energy drinks pose mostly mild caffeine/sugar effects.

Chris Cornell – "Black Hole Sun" (Acoustic Version, 2015)