Trends in documented cannabis use disorder among hospitalized adult epilepsy patients in the United States

Objective: Patients with epilepsy are at increased risk for mental health and substance abuse disorders. Given ongoing contemporary societal controversies about medicinal and recreational cannabis use, we aimed to as-certain recent nationwide prevalence, trends, and psychiatric diagnoses associated with cannabis use disorders (CUD) among epilepsy patients. Methods: We interrogated the National Inpatient Sample database comprising a total of 398,936 adults (aged 18 years and above) with epilepsy between the years 2006 and 2014, identified using the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes 780.39 and 345.X. A subset of these patients with a secondary discharge diagnosis of CUD (ICD-9-CM: 304.30, 304.31, 304.32, 305.20, 305.21, and 305.22), excluding those in remission, were selected. Logistic regression model adjusting for gender, race, age, primary payer, bed size, household income, region, teaching hospital, admission day, length of stay (LOS), Charleson Comorbidity Index (CCI) and, year category was used to ascertain the independent associations of demographic features and mental health comorbidities with CUD. Finally, we generated CUD trend estimates overall and by psychiatric diagnoses. Results: Of all hospitalized patients with epilepsy, 3.19 % had CUD. After adjusting for confounders, CUD was higher in males, Blacks, those aged 18 - 44 years, those with lower incomes, and those hospitalized during more recent years. CUD was more likely to be present in epilepsy patients with depression, bipolar disorder, and tobacco use disorder (TUD). In contrast, alcohol use disorder (AUD) was associated with lower odds of CUD. Overall, CUD prevalence more than doubled among epilepsy patients (2.18 % in 2006 to 4.41 % in 2014). Among patients with PTSD, CUD prevalence increased over fivefold, and it nearly tripled in those with tobacco use disorder. Significance: Documented CUD has doubled among hospitalized patients with epilepsy in the United States over the last decade and is especially more prevalent in specific demographic and mental health disorder groups. Increased awareness and potential screening for CUD in high-risk epilepsy patients may be warranted, given the risk for potential complications.