Substance use disorders have significant costs to the US economy, contributing to billions of dollars in healthcare expenditures and damaging countless lives each year. The underlying causes of alcohol and other drug use are many. Researchers identify hundreds of variables as potential contributors to or predictors of substance use. Several of the most commonly abused substances – alcohol, tobacco, and cannabis – are legal for adults in most places. Recreational use of cannabis is currently legal in 11 states. Given the ease of access to and highly addictive nature of these substances, understanding what drives a person to use them is crucial to preventing and treating the abuse of them.
Traumatic Events and Child Development
Many developmental risk factors can contribute to substance use disorder (SUD), especially those experienced during childhood and young adulthood. Substantial research shows events such as exposure to violence during childhood (physical, emotional, or sexual), and witnessing traumatic experiences, especially within the home (domestic abuse or substance misuse) can have negative impacts on early development and long-term health. Studies identify adverse childhood experiences (ACEs), as these events are known, as strong contributors to SUD in young adults. Childhood trauma correlates with a multitude of negative consequences in both early life and adulthood. These include alterations in brain structure and function, variation in personality traits, and increased risk of depression and anxiety. Genetics also play a role. Genes interact with other influences to either increase the predisposition for the development of a substance abuse disorder or support resilience and attenuate risk.
Homelessness and Trauma
In addition to the ACEs described above, low socioeconomic status and housing instability also contribute to substance use disorders. Homelessness affects over a half million people on any single night in the United States, many of them children. Children experience homelessness for a variety of complex reasons that often include trauma. Other experiences that may lead to homelessness include:
- Traumatic stress
- Childhood abuse and neglect
- Interpersonal violence
- Mental health issues
- Substance use issues
The experiences leading up to homelessness, as well as homelessness itself, have a lasting impact. Children are severely challenged by the unpredictability, dislocation, and chaos that characterize periods of homelessness and can contribute to SUD and other mental health disorders. Children experiencing homelessness frequently face the following:
- Poor physical and behavioral health outcomes
- Missed educational opportunities
- Instability at home and in school
- Family separation
Foster care, which some children also experience, is a social care system designed to provide temporary housing and care for children whose parents are unable to care for them. Children whose home environment puts their health and safety at risk may also be sent to foster homes. Removal from a potentially harmful environment may shelter children from the adverse influences that can contribute to early adult SUD. Conversely, however, removal or separation from families may cause feelings of uncertainty and abandonment. In the absence of professional support, these emotional states can also lead to mental health or substance abuse issues.
Early Homelessness and Addiction in Young Adults
A recent study examined the impact of homelessness, foster care, and adverse childhood experiences (ACEs) before the age of 18 on the subsequent development of three of the most common SUDs: alcohol use disorder (AUD), tobacco use disorder (TUD), and cannabis use disorder (CUD). The ACEs described in the study included:
- Emotional Abuse
- Physical Abuse
- Household Mental Illness or Suicide
- Parental Separation, Divorce or Death
- Household Criminality
- Emotional Neglect
- Physical Neglect
Overall, the results of the study show far lower prevalence of individual ACEs among those raised in a typical home compared to those who experienced foster care or homelessness. Experiencing homelessness as well as one or more of the listed ACEs before the age of 18 correlates significantly with alcohol, tobacco, and cannabis use disorders in young adults.
Interestingly, the study also indicated no significant association between foster care and risk of or protection from SUDs. The authors conclude that homelessness during childhood can therefore be considered another detrimental adverse childhood experience that is a risk factor for the most common substance use disorders in young adulthood.
Housing Instability: A Preventable Trauma
Given the magnitude of the current epidemic of homelessness in the US, these results should raise concern. According to a January 2020 report, more than 1.5 million public school students nationwide said they were homeless at some point during the 2017-2018 school year. This number may have grown even higher in recent months due to the increase in unemployment rates that have resulted from the coronavirus pandemic. While some of the factors contributing to substance use disorders cannot yet be addressed or treated (e.g. genetics), childhood homelessness is preventable, and advancements in homeless prevention strategies might attenuate SUD risk. Because ACEs are common and strongly related to a variety of substance misuse and related behavioral health outcomes, preventing ACEs, including homelessness, and engaging in early identification of people who have experienced them, could have a significant impact on developing prevention and treatment programs.