A 50-year-old woman presents to the clinic for a 6-month fol…

A 50-year-old woman presents to the clinic for a 6-month follow-up. Her medical history includes osteoarthritis of multiple joints, major depression, insomnia, alcohol use disorder, diabetes, and chronic obstructive pulmonary disease (COPD). She has a 25-pack-year history of smoking. She does not report new complaints beyond chronic pain, for which she is requesting refills. She takes methadone 10mg TID, cyclobenzaprine 5 mg TID for muscle spasms, and zolpidem 10mg at night as needed for insomnia. A review of the prescription drug monitoring program (PDMP) shows she has no apparent irregularities and fills medications on time. Which of the following risk factors is most likely to increase her risk of accidental overdose?