Tobacco/nicotine dependence as a risk factor for substance use disorders and related mental health conditions among cancer patients.

Background: Cancer patients often face multiple comorbidities and are at risk for various mental health conditions and substance use disorders. Tobacco/nicotine dependence (TND) is a known risk factor for poor health outcomes and has been associated with psychiatric disorders including substance use disorder. However, the specific relationship between TND and the risk of substance use disorder and mental health conditions among cancer patients remains underexplored. This study aimed to assess the association between TND and the risk of comorbid conditions among cancer patients.

Methods: Data were obtained from a database of electronic health records for patients from the University of California health system. The odds for every condition among cancer patients with TND were calculated and compared with those for cancer patients without TND. ORs were adjusted for gender, ethnicity, and race.

Results: Three thousand seven hundred and ninety-one cancer patients with TND had 252,619 total conditions, and 51,711 cancer patients without TND had 2,310,880 conditions. After adjusting for confounders, the condition for which TND most exacerbated risk was psychoactive substance-induced organic anxiety disorder (OR = 16.3, p < 0.001). This appeared consistent with the second, third, and fifth most-exacerbated conditions: stimulant use disorder (OR = 12.8, p < 0.001), cocaine induced mental disorder (OR = 11.0, p < 0.001), and cocaine use disorder (OR = 11.0, p < 0.001). Different conditions exacerbated by TND include acute alcoholic intoxication (OR = 11.4, p < 0.001), opioid use disorder (OR = 7.6, p < 0.001), schizoaffective disorder (OR = 7.4, p < 0.001), and cannabis use disorder (OR = 6.3, p < 0.001).

Conclusions: Our findings reveal a strong association between TND and an increased risk of substance use disorder and mental health conditions among cancer patients. Specifically, cancer patients with TND were at an elevated risk for psychoactive substance-induced organic anxiety disorder, stimulant use disorder, and cocaine-related disorders. Additionally, TND was associated with an increased risk of acute alcoholic intoxication, opioid use disorder, schizoaffective disorder, and cannabis use disorder. These findings underscore the need for comprehensive screening and interventions to address TND and comorbid conditions among cancer patients.