Molecular Diagnosis of Bacterial Meningitis in Ethiopia: A Narrative Review of Current Evidence and Implementation Gaps.

Polysubstance use, or the longitudinal, sequential, or simultaneous use of multiple substances, is a persistent and growing concern. Indeed, over 20 % of respondents in a 2022 national (United States) study reported polysubstance use, with prescription drugs plus alcohol or cannabis plus alcohol being the most commonly reported polysubstance combinations []. Clinical populations that engage in polysubstance use experience detrimental outcomes including worsened substance use disorder (SUD) severity, mental and physical health status, treatment response, and mortality, as well as increased risk for overdose, suicide, and infectious and sexually transmitted disease [,]. In one longitudinal study, persistent polysubstance use was associated with the poorest biological aging and midlife health and financial/social preparedness []. Nearly all individuals with a SUD additionally consume other substances and the majority have at least one other diagnosed SUD []. The increasing prevalence of alcohol and opioid co-use is a pressing concern - from 2002 to 2012, there was a 15-fold increase in the number of individuals with AUD and comorbid OUD []. Alcohol and opioid co-use accelerates the progression of problematic use and is more harmful than either substance used alone [] (the number of deaths resulting from opioid overdose also involving alcohol increased 5.5 times between 1999 and 2017 []). Thus, there is an urgent need to address alcohol and opioid polysubstance use to limit harms and improve outcomes. The choice to use one or more substances may depend on life history, current environment, and personality type. Experiencing stressful life events is predictive of polysubstance use [–]. Additionally, maladaptive coping (including aggressive, reactive, or substance-driven coping) is thought to play a role in mediating polysubstance use [–]. Behavioral or psychological phenotypes of an individual may also influence which substance or substances to use, and if that choice remains constant in all cases or is circumstance dependent. For example, both preclinical and clinical studies have shown that higher levels of anxiety and novelty-seeking are correlated with increased alcohol consumption, albeit with different patterns of use [–]. There may be a relationship between anxiety-like or reward-related behaviors and increased opioid consumption, but findings remain mixed [,]. However, these types of investigations have been limited to a single substance, so conclusions about pre-existing behaviors or personality traits and polysubstance use remain limited. Sex differences in substance use are also thought to be a critical factor, but little focus has been placed on understanding polysubstance use in relation to biological sex.