Consumption of alcohol is associated with acute and chronic adverse health outcomes including cardiovascular diseases, liver damage, cancers, psychiatric conditions, as well as intentional and unintentional injuries . Besides direct health risks, alcohol consumption is also correlated with negative social and behavioral outcomes, such as risky sexual behavior [2–4]. Despite widespread interventions to raise awareness of the harmful consequences of alcohol use, global data suggest an increase in alcohol consumption among young people [1, 5]. For example, data from the 1998 National Drug Strategy Household survey in Australia show that successive birth cohorts were more likely to report alcohol use by age 15, with 16% of adults born between 1940-1944 reporting such use compared to 56% of those born in 1980-1984 . In the United States, an analysis of national survey data collected between 1979 and 2005 shows a considerable increase in volume of alcohol consumed and the number of days in which respondents report that 5 or more drinks were consumed among young people aged 18-25 .
Concern about alcohol consumption among young people has led to a mushrooming of literature that seeks to understand the correlates of alcohol abuse among the youth. Although there is now ample literature on alcohol consumption in sub-Saharan Africa, much of it focuses on the links between alcohol consumption and sexual behavior and sexually transmitted diseases (in particular HIV) among adult and adolescent populations [2, 4, 8–10]. There is, however, a paucity of studies that explore the determinants of alcohol use among adolescents in sub-Saharan Africa and, in particular, that examine the effects of adverse childhood experiences on alcohol use. Yet, the complex impacts of adverse childhood experiences on young people's development and behavior may have an important bearing on the effectiveness of interventions geared at reducing alcohol consumption among the youth. With this in mind, we examine the association between four adverse childhood experiences (i.e. living in a food insecure household, living in a household that suffered due to an adult member's drinking, having been physically abused, and having been coerced into having sex) and self-reported past-year drunkenness among adolescents aged 12-19 years living in Burkina Faso, Ghana, Malawi, and Uganda.
Alcohol consumption among adolescents and youth in sub-Saharan Africa
Existing literature on alcohol consumption among adolescents in sub-Saharan Africa suggests that a substantial proportion of adolescents have consumed or currently consume alcohol. Two Ghanaian studies conducted among secondary school students  and among nationally-representative samples of in- and out-of-school youth  found that the prevalence of lifetime alcohol use was approximately 25%. According to the 2003 World Health Survey , the proportion of 18-24 year old males reporting heavy drinking (defined as consuming five or more standard drinks in one sitting at least once a week) was estimated at 8% in Burkina Faso, 1% in Ghana, and 5% in Malawi. Comparative figures for females were 5%, 0.3%, and 0.2% in Burkina Faso, Ghana, and Malawi respectively. Age-disaggregated data were not available for Uganda in the World Health Survey; however, data from the 2003 Ugandan Global School-based Student Health Survey show that 14% and 12% of boys and girls aged 13-15 years, respectively, reported that they had ever drunk so much alcohol that there were really drunk . In a study conducted among school going adolescents aged 11-17 years in Uganda, 18% of adolescents reported that they had ever drank alcohol . Studies conducted elsewhere in sub-Saharan Africa, also show that a relatively high proportion of young people report alcohol use. For example, in a study among secondary schools students in south western Nigeria , 13% of students reported current alcohol use while 26% had ever consumed alcohol.
Although cross-national variations in the measures and approaches used to assess alcohol use make it difficult to make comparisons across countries, existing data suggest that adolescents in sub-Saharan Africa consume less alcohol than their peers in North America and Europe [1, 5]. Further, global data show that the disease burden, as measured by Disability Adjusted Life Years (DALYs), attributable to alcohol use is significantly higher in Europe and the Americas. However, within Africa, the overall disease burden attributable to alcohol use is not insignificant and evidence suggests that alcohol-related problems will contribute more to the overall disease burden over time [13, 14]. Variations in socio-cultural contexts, as well as policies relating to alcohol production, sales and consumption may also lead to wide diversity in alcohol consumption patterns within the region . For example, in Malawi and Uganda, the sale of alcoholic beverages to children under the age of 18 years is prohibited, while Burkina Faso and Ghana have no age limits for the purchase of alcohol. Further, while Uganda has no restrictions on the hours of sale, days of sale, or places where alcohol can be sold, Burkina Faso has some restriction on where alcohol can be sold . Alcoholic beverages in all the four countries are taxed ; however, taxes are primarily applied to industrially-produced alcoholic beverages and not to traditional home-made brews, which are readily available and cheaper in many sub-Saharan African countries.
Adverse childhood experiences and consequences
A substantial body of literature based on data collected outside of sub-Saharan Africa points to the long-term consequences of adverse childhood experiences. For example, in addition to the inherent trauma and rights violations involved in child sexual abuse, a history of childhood sexual abuse has been shown to be associated with depression and other psychosocial impacts that increase the likelihood of risky behavior later in life [16–18]. Sexual abuse has been linked to teenage drug and alcohol use, younger age at first intercourse, and teenage parenthood [19–23]. Dube and colleagues  postulate that physiologic changes in response to abuse and trauma in childhood may impact on neurodevelopment in ways that hinder emotional coping, leading to potentially harmful behavior such as substance use and dependence.
Sexual victimization of children is not uncommon in sub-Saharan Africa. In a study conducted among adolescent females in Rakai, Uganda, 14% of respondents reported that their first sexual intercourse was forced . Lalor  in his review of the literature on sexual abuse in the region found that between 3% and 7% of respondents in several South African studies reported unwanted or forced sexual intercourse before the age of 17 or 18, with the proportions rising to between 26% and 54% when unwanted kissing and touching were considered. In the few studies in Lalor's review that examined male-female differences, a greater proportion of females than males reported sexual abuse.
Food insufficiency is a common problem in resource-constrained households. Low incomes and high food prices, especially in the context of a global economic crisis, mean that the poor in many nations, and in particular those in the developing world, have to reduce food intake and rely on less-nutritious foods . With the exception of a few studies examining the link between food insecurity and sexual risk behavior among adults , there is, to the best of our knowledge, no study documenting the association between food insufficiency and behavioral as well as psychological outcomes in children and adolescents in sub-Saharan African countries. Studies from the United States show that adolescents from food insecure household are more likely to have or to report chronic depression , suicidal attempts , desire to die , thoughts of death , irritability, anxiety or worry , socialization problems such as aggression , and poorer schooling outcomes [30, 31]. The processes that lead to the observed linkages between food insecurity and behavioral and psychosocial outcomes in children are not well understood. Alaimo and colleagues  postulate biological mechanisms, stressor effects, and indirect associations through modified parental emotions and parenting behavior. With respect to modified parenting behavior, they suggest that in food insufficient households, parents may be subjected to high levels of stress and consequently be unable to optimally care for their children. As a result of poor parental control, children from food insecure households may be more likely to engage in risk behavior including alcohol use.
Growing up in a household where a parent or other household member has a drinking or drug problem that negatively impacts on the entire household may also contribute to behavioral problems during adolescence [32, 33]. Zucker and colleagues  in their review of the literature on early developmental influences of underage and problem drinking highlight several possible pathways through which familial alcoholism may lead to drinking problems in children and adolescents. First, young people's attitudes towards alcohol are shaped in part by interactions in the social context in which children are raised. Second, having parents or other adults who drink in a household increases the likelihood that alcohol is available and accessible in the home. Third, if the adult with problem drinking is a primary caregiver, this may have implications for parenting behavior and levels of discipline. Last, genetic predisposition to problem drinking is likely where the child and adult with problem drinking are biologically related.
Understanding the long-term consequences of adverse childhood experiences on alcohol abuse among adolescents is useful for informing alcohol abuse prevention and treatment programs. Yet, there is a paucity of research on adverse childhood experiences and later alcohol use in sub-Saharan Africa outside of South Africa. Further, with few exceptions , there is a dearth of studies examining the effects of exposure to multiple adverse events during childhood on alcohol abuse. Given that youth comprise a significant proportion of sub-Saharan Africa's population and since young people's behavior have critical long term implications for a healthy and successful transition to adulthood , this study seeks to address these gaps by drawing on a rich set of nationally-representative data collected from adolescents aged 12-19 years living in Burkina Faso, Ghana, Malawi, and Uganda. We hypothesize that young people who have experienced adverse events during childhood will be more likely to report drunkenness in the 12 months preceding the survey. Further, we postulate that exposure to multiple adverse events heightens the likelihood of reporting being drunk.