Psychiatric Comorbidity and Multimorbidity in the EAGLES Trial: Descriptive Correlates and Associations With Neuropsychiatric Adverse Events, Treatment Adherence, and Smoking Cessation

Nicotine Tob Res. 2021 Aug 29;23(10):1646-1655. doi: 10.1093/ntr/ntab056.


Introduction: Psychiatric and substance use disorders represent barriers to smoking cessation. We sought to identify correlates of psychiatric comorbidity (CM; 2 diagnoses) and multimorbidity (MM; 3+ diagnoses) among smokers attempting to quit and to evaluate whether these conditions predicted neuropsychiatric adverse events (NPSAEs), treatment adherence, or cessation efficacy (CE).

Aims and methods: Data were collected from November 2011 to January 2015 across sixteen countries and reflect the psychiatric cohort of the EAGLES trial. Participants were randomly assigned to receive varenicline, bupropion, nicotine replacement therapy, or placebo for 12 weeks and were followed for an additional 12 weeks posttreatment. NPSAE outcomes reflected 16 moderate-to-severe neuropsychiatric symptom categories, and CE outcomes included continuous abstinence at weeks 9-12 and 9-24.

Results: Of the 4103 participants included, 36.2% were diagnosed with multiple psychiatric conditions (20.9% CM, 15.3% MM). Psychiatric CM and MM were associated with several baseline factors, including male gender, nonwhite race or ethnicity, more previous quit attempts, and more severe mental health symptoms. The incidence of moderate-to-severe NPSAEs was significantly higher (p < .01) in participants with MM (11.9%) than those with CM (5.1%) or primary diagnosis only (4.6%). There were no significant (ps > .05) main effects or interactions with treatment condition for diagnostic grouping on treatment adherence or CE outcomes.

Conclusions: While having multiple psychiatric diagnoses increased risk of developing moderate-to-severe NPSAEs during a quit attempt, neither CM nor MM were associated with treatment adherence or odds of quitting. These findings reassure providers to advise smokers with multiple stable psychiatric conditions to consider using Food and Drug Administration (FDA)-approved medications when trying to quit.

Implications: Psychiatric MM may be associated with development of NPSAEs when smokers make a medication-assisted quit attempt, but it does not appear to be differentially associated with medication compliance or efficacy. Prescribing healthcare professionals are encouraged to not only promote use of FDA-approved pharmacotherapies by smokers with complex psychiatric presentations, but also to closely monitor such smokers for neuropsychiatric side effects that may be related to their mental health conditions.

Nct #: NCT01456936.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bupropion
  • Humans
  • Male
  • Multimorbidity
  • Nicotinic Agonists / adverse effects
  • Smoking Cessation*
  • Tobacco Use Cessation Devices
  • Treatment Adherence and Compliance
  • Varenicline / adverse effects


  • Nicotinic Agonists
  • Bupropion
  • Varenicline

Associated data