• Pharmacological profiling across opioids and cannabinoids, with dose–response effects, abstinence syndromes and biomarker studies in urine and metabolism, revealing shared pharmacodynamics and therapeutic implications [1], [8], [9], [11], [15], [17], [20].

• Public health framing and epidemiology of substance use: alcohol, tobacco, and cannabis policy, homelessness, and liver disease epidemiology shaping addiction burden and policy responses [4], [6], [12], [13], [16], [18].

• Cannabis pharmacology and medicinal chemistry: isolation and structure–activity insights for cannabidiol, cannabinol, and related cannabinoids [8], [9], [15], [17].

• Psychological and behavioral dimensions of addiction: personality typing, impact on alcohol/personality inventories, and homelessness/behavioral health contexts [3], [7], [16], [18].

• Clinical toxicology and medical complications of substance misuse: toxinology, infectious complications, liver disease, metabolism, and analgesic pharmacology [5], [6], [10], [11], [14], [19].