Introduction
Although abuse of psychoactive substances often has serious physical, emotional, behavioral, economic, and social consequences for adults, children who live with alcoholic or drug-abusing parents can also fall victim to the deleterious familial environments these caregivers often create. The empirical literature has generally found Children of Alcoholics (COAs) exhibit elevated rates of social, emotional, and behavioral problems compared to children of nonalcoholics. Unfortunately, research examining the functioning of children whose parents primarily abuse drugs other than alcohol, often referred to as Children of Substance Abusers (COSAs), is far less developed than the COA.

Children Living with Caregivers Who Abuse Drugs and Alcohol
Epidemiological Evidence
More than 10 million people in the U.S. meet abuse or dependence criteria for either alcohol or illicit drugs. Among the most detrimental consequences of these disorders are the negative effects of parental alcoholism and drug abuse on children who live in these homes. Unfortunately, many children live with and are raised in families in which a parent abuses alcohol or other drugs; the 2001 National Household Survey of Drug Abuse indicated 6 million children (9%) lived with at least one parent who abused or was dependent on alcohol or an illicit drug during the past year. Among parents living with their children, fathers (8%) were more likely than mothers (4%) to abuse or be dependent upon a psychoactive substance.

Children of Alcoholics (COAs)
An extensive literature now exists examining the functioning of COAs. In general, these investigations have concluded COAs exhibit elevated rates of various psychosocial problems. For example, both internalizing (e.g., anxiety, depression), and externalizing behavior problems (e.g., conduct disorder, alcohol use, drug use) are significantly more common among COAs than children of nonalcoholics. Several factors appear to be associated with the problems observed in COAs. Some of these children are prenatally exposed to alcohol during gestation and thus are at risk for physical and central nervous system insults, resulting, in some instances, in Fetal Alcohol Syndrome (FAS) with its cognitive, affective, growth, and morphologic sequelae. In addition, COAs are also often exposed to inadequate parenting, negative parent-child interaction patterns, and increased likelihood of physical abuse; each of these is related to negative child outcomes.

Although COAs are at heightened risk for a wide range of negative outcomes compared to children of nonalcoholic parents, most COAs do not develop clinical disorders and show normal psychosocial development. At present, however, very little is known about possible protective factors, such as a supportive family environment, social support, and responsive parenting by the nonsubstance-abusing partner, that may moderate or "buffer" the negative effects of living with an alcoholic parent.

In summary, research on COAs can be broadly classified into studies of FAS, the transmission of alcoholism to offspring, psychobiologic markers of vulnerability, and psychosocial characteristics. These studies hypothesize differences between COAs and children of nonalcoholics lead to maladaptive behaviors later in life, including emotional problems, academic failure, or alcoholism.

Parental Drug Abuse Versus Alcohol Abuse and Effects on Children
Does Substance Type Matter?
As noted in several reviews, there has been a tendency in the literature to assume, implicitly or explicitly, that type of parental substance abuse is largely a secondary issue when examining effects on the family. Consequently, many authors presume the findings from the COA literature apply to COSAs. However, viewed from several different vantages, we would expect important differences in drug-abusing and alcoholic families and in the children from these homes. Specifically, families in which one or both parents use illicit drugs, particularly opiates and cocaine, are much more likely to be living in poverty, whereas alcohol users are more likely to be living across a range of socioeconomic contexts. Because opiates and cocaine are illegal drugs, there is a certain amount of secrecy that pervades the contexts in which they are used, which may create isolation for drug-abusing individuals and their families. In contrast, alcohol is a legal and socially accepted substance. Relatedly, there are fewer social supports, public advocacy, and treatment for drug abusers and their families. Drug use, especially opiates and cocaine, is associated with criminal activities and places the parent at risk for arrests and imprisonment. Thus, the illegality, lifestyle, lack of social support, and health risks associated with opiate and cocaine use result in important differences between families in which a parent is addicted to an illegal drug versus alcohol.

Comparisons of families in which a parent primarily abuses one or more illicit drugs versus those in which parents abuse alcohol support this description. Compared to paternal alcoholism, paternal illicit substance abuse is associated with greater detrimental effects in terms of interparental conflict, quality of parenting, and psychological functioning. The larger developmental literature has shown the importance of each of these factors for child outcomes. Thus, as compared to homes with an alcohol-abusing parent, as a group, the homes of children living with a male drug-using parent may experience a greater number and greater severity of a broad range of familial disruptions. Therefore, children living with drug-abusing fathers are likely to manifest more negative adjustment.

Overview of Empirical Findings on COSAs
Research on COSAs is far less evolved than the COA literature. During infancy and preschool years, some areas of disturbance have been identified (e.g., problems with attention), but there is little evidence of any global psychiatric impairment. By late childhood and early adolescence, however, a number of problems evolve and have been documented. Sowder and Burt (1980) reported many children of heroin-dependent mothers receiving outpatient treatment experienced emotional and school-related difficulties. Similarly, parental drug use has been associated with reports of increased child symptoms on standardized rating scales of child behavior. In a sample of cocaine- and opiate-addicted mothers, Luthar and colleagues (1998) found nearly 66% of COSAs had at least one major psychiatric diagnosis by the time they were 12 years old. In a series of investigations conducted by members of the AFRG, comparisons between school-aged COSAs and COAs revealed that COSAs had significantly poorer general psychosocial adjustment and were more likely to have a lifetime psychiatric diagnosis.

Although these investigations found COSAs often display emotional and behavioral difficulties and indicated that parental drug abuse was a significant risk factor for emotional and behavioral problems in children, far less is known about the mechanisms underlying this risk. Some investigators have argued the psychosocial problems observed in COSAs are largely a consequence of prenatal chemical exposure, which results in growth deficits and neurodevelopmental problems that are apparent throughout early childhood. However, others have failed to find this link, particularly when other risk factors, such as poverty and less optimal care giving environments, are carefully controlled. Conversely, other authors have posited the effects of postnatal social exposure (i.e., the concomitant sequelae of drug use by parents, such as poor parenting, high interparental conflict) are the primary contributory factors in the emotional and behavioral problems observed in COSAs. Young (1997) argued that investigations examining factors related to the psychosocial adjustment of COSAs have been unable to disentangle prenatal and postnatal social exposure effects because the children included in the studies often live with parents who are currently or have recently abused drugs and have typically been exposed to drugs during gestation due to mothers’ substance use. This is a consequence of the fact that most COSA studies have focused on children (usually infants) of drug-abusing mothers. Research exploring the effects of parental substance use on preadolescent school-aged children (i.e., between 5-12 years) is very rare, as is research that focuses on postnatal social exposure effects without the confound of prenatal chemical exposure.

Representative Articles:

Fals-Stewart, W., Kelley, M. L., Fincham, F. D., Golden, J., & Logsdon, T. (2004). Emotional and behavioral problems of children living with drug-abusing fathers: Comparisons with children living with alcohol-abusing and non-substance-abusing fathers. Journal of Family Psychology, 18, 319-330.

Cooke, C. G., Kelley, M. L., Fals-Stewart, W., & Golden, J. (2004). A comparison of the psychosocial functioning of children with drug- versus alcohol-dependent fathers. American Journal of Drug and Alcohol Abuse, 130, 695-710.