Hospitalizations due to the use of psychoactive substances in Portugal: Impact assessment of the 2008 economic crisis

Background: The number of harmful users of psychoactive substances and the estimated number of deaths associated with consumption have been increasing globally. Due to the growing and recurring nature of this issue, there is a clear ongoing rise in human, social, health, and economic costs associated with the harmful consumption of illicit substances, making it a Public Health problem. Economic recessions are one of several contexts that can interfere with usage patterns and health consequences. Some studies suggest an increase in consumption during periods of economic recession, but there is a shortage of literature evaluating the impact on health outcomes and the evolution of consumption and its outcomes in the post-crisis period. This study aims to assess the impact of the 2008 economic crisis and its aftermath on hospital admissions related to the use of psychoactive substances in Portugal. 
Materials and methods: This impact analysis will target data relative to the period between January 1, 2002, and December 31, 2018, through a quasi-experimental interrupted time series study. The dependent variable will be the incidence of hospitalizations due to the use of psychoactive substances per municipality per year. To predict the evolution of this variable, a sequential time trend chart will be created and then adjusted to the most suitable regression model. To identify the statistical difference, observed values after the onset of the crisis will be compared with projected values using the chosen regression model. The process will then be repeated for observed values in the post-crisis period. 
Expected Results: According to existing literature, if the increased consumption that appears to occur during economic crises leads to worse health outcomes, an increase in the incidence of hospitalizations for mental and behavioral pathologies due to psychoactive substance use can be expected during the that period. It is also expected that negative effects on health outcomes will persist in the post-crisis period, with a gradual return to the previous trend. 
Conclusions: The results of this study can influence local, regional, and national public health policies and measures, not only during economic crises but also outside of these periods. The aim is to promote a rational allocation of resources to address this issue, ranging from prevention, low threshold/harm reduction and damage minimization, treatment to societal reintegration, with a special focus on preventing harmful psychoactive substance consumption through health literacy and destigmatization.