The risk for persistent adult alcohol and nicotine dependence: the role of childhood maltreatment

Alcohol and nicotine are legal, readily available, and commonly used substances that contribute substantially to preventable morbidity and mortality worldwide (1–4). Alcohol and nicotine dependence are common disorders (5, 6) associated with elevated health risks (7, 8). While individuals who use alcohol or nicotine heavily for short periods face some increased risk, individuals with prolonged, heavy use face substantial risk (9, 10). Thus, identifying individuals at risk for persistent alcohol and nicotine dependence among those who experience these disorders has considerable public health importance. Many studies have addressed the course of substance use disorders among patients in treatment (11–17). However, patient studies may be biased by numerous confounds and selection factors (18, 19). To better understand the course of alcohol and nicotine dependence and its predictors, prospective epidemiological studies are useful (18). Researchers studying predictors of persistent substance disorders in large national samples have focused on demographic characteristics (20), psychiatric comorbidity (21, 22), and symptom severity and treatment (23). These all provide important information, but leave many other possible predictors unexplored. Childhood maltreatment is an important factor that may predict the persistence of alcohol and nicotine dependence. Childhood maltreatment refers to harm, neglect, or exploitation of children that may be physical, sexual, or emotional in nature (24). Nationally representative research suggests that nearly one third (30.1%) of the U.S. population is affected by physical, sexual, or emotional abuse, or physical or emotional neglect (25). Researchers have already found that childhood maltreatment predicts increased alcohol and nicotine use (26–29) and dependence symptoms (30, 31), as well as substance use problem severity (32–34). However, whether childhood maltreatment increases the risk for persistence of alcohol and nicotine dependence has not been studied, and chronologically distal risk factors for lifetime occurrence are not necessarily the same factors that predict disorder course once it has begun. One prior study assessed the influence of childhood maltreatment on the course of substance use; this case-control study found that childhood neglect (but not abuse) predicted course of illicit drug use over young and middle adulthood (35). However, no studies have assessed the effect of childhood maltreatment on course of dependence on the most widely used, licit substances: alcohol and nicotine. Given the impairment and consequences associated with longstanding dependence on these substances (6, 36), investigating whether childhood maltreatment predicts the persistence of alcohol and nicotine dependence in a large nationally representative sample of the general population would provide findings with important public health significance. Assessing a range of maltreatment experiences could help determine which specific experiences increase risk; controlling for exposure to other aspects of a difficult childhood (e.g., parental death or divorce) could clarify whether any significant maltreatment effects are simply due to a generally adverse childhood environment. The present study utilizes data from a large, nationally representative US prospective study, in which participants were assessed at two waves, three years apart. First, we provide descriptive information on childhood physical, sexual, and emotional abuse, and physical and emotional neglect, among individuals with baseline alcohol and nicotine dependence, and among those with persistent disorders. Second, we assess the relationship between these five types of childhood maltreatment and the persistence of alcohol and nicotine dependence among those with baseline diagnoses. We conduct these analyses with and without control for other adverse childhood events, to determine whether significant associations are simply the result of a generally difficult childhood. Third, we assess which maltreatment types remain significant when all maltreatment types are considered together, to determine unique effects. Finally, we assess whether experiencing a greater number of types of childhood maltreatment incrementally influences the risk for persistent alcohol and nicotine dependence.