Longitudinal assessment of the effect of cannabis use on hospital readmission rates in early psychosis: A 6-year follow-up in an inpatient cohort

Abstract

Cannabis is the most commonly used illicit drug in psychosis patients and has been identified as a risk factor for relapse and subsequent hospital readmission, having substantial economic implications. To clarify the contribution of cannabis consumption to hospital readmission, a consecutive inpatient cohort of 161 early psychosis patients was included into the study. Data on cannabis use at admission and number of hospital readmissions and length of stay (LOS, number of inpatient days) in a 6-year follow-up was extracted from clinical notes. 62.4% of the patients had lifetime cannabis use. Their admission lasted on average 54.3 ± 75 days and over the following 6 years patients had 2.2 ± 2.8 hospital readmissions, for a total of 197.4 ± 331.5 days. Cannabis use significantly predicted the number of hospital readmissions and LOS in the following 6 years, the latter remaining significant after adjusting for use of other substance. Cannabis-using patients of male gender and Black ethnicity had a longer LOS at follow-up compared to female patients and other ethnic groups, respectively. Having a history of cannabis use when admitted to an early intervention inpatient unit for psychosis is associated with a higher number of subsequent hospital readmissions and a longer LOS, especially in male and Black patients.

Early onset of cannabis use and violent behavior in psychosis

“…Third, history of violence and CU until age 15 were the two main risk factors for VB. In our EPP cohort, 64% of the patients had a history of lifetime CU, which is consistent with other studies (range 24-74%) [3,[50][51][52]. This percentage was significantly higher (79%) for patients in the VP group.…”

Pre-Discharge Predictors of 1-Year Rehospitalization in Adolescents and Young Adults with Severe Mental Disorders: A Retrospective Cohort Study

“…As regards alcohol and substance use disorders, our sample shows rates that are considerably higher than those reported in the general population both at a national and at a European level [21], consistently with epidemiological data showing high rates of comorbid addictive behaviors among subjects with severe mental disorders [22]. A longitudinal analysis recently estimated that having a history of cannabis use when admitted to an early intervention inpatient unit for psychosis was associated with a higher number of subsequent hospital readmissions [23]. Furthermore, higher rates of readmission in individuals who started using drugs in their youth, compared to people who started later in their life, were estimated [24].…”

Adolescent‐onset heavy cannabis use associated with significantly reduced glial but not neuronal markers and glutamate levels in the hippocampus

“…[2][3][4][5] Cannabis use, particularly adolescent onset regular cannabis use, has also been associated with increased risk of onset 6,7 and relapse [8][9][10] of psychosis, as well as greater risk of other adverse mental and behavioural outcomes [11][12][13] and longer hospitalizations. 14 However, the neurochemical underpinnings of these behavioural, cognitive, and mental health effects associated with persistent cannabis use remain unclear. [15][16][17] Delta-9-tetrahydrocannabinol (THC), the main psychoactive component in cannabis, is a partial agonist at the type 1 cannabinoid receptors (CBR1), 18 which are mostly expressed in GABAergic and glutamatergic neurons.…”