Currently, there are no established methods to inject chemicals or hormones that can specifically induce emotions like hate, anger, or guilt in individuals. The closest existing treatment is testosterone patches, which can increase aggression across various life situations. Additionally, some antidepressants may lead to emotional side effects. Nicotinic receptor agonists are noted for causing irritability, similar to withdrawal symptoms in smokers. Treatments for opiate addiction involve agonists that bind to mu receptors, effectively detoxifying users but with significant pain and high costs. Recreational drugs can elicit positive emotions, while substances like alcohol and PCP can provoke rage in certain individuals.