New research finds that a young adult\u2019s risk for dual diagnosis is linked to having a mother who smokes cigarettes and who displays an unusually low amount of parent-child attachment. In addition, the researchers concluded that children born to fathers with serious alcohol problems are also at risk for simultaneously occurring problems with substance abuse\/addiction and some other form of mental illness. Experts in the field refer to this combination of problems as a dual diagnosis. In a study published in October 2014 in the journal Addiction, a team of researchers from Australia\u2019s University of Queensland examined the family-related factors that make it more likely that a young adult will meet the criteria for this condition, which can have an unusually severe, damaging impact on the well-being of affected individuals. Dual Diagnosis Millions of people across the U.S. have the overlapping symptoms that characterize dual diagnosis, the National Alliance on Mental Illness reports. In fact, about 50 percent of all people affected by major depression, bipolar disorder or some other form of severe mental illness also qualify for a diagnosis of substance abuse\/addiction (i.e., substance use disorder). In turn, over 33 percent of all people with alcohol-related substance use disorder and over 50 percent of all people with drug-related substance use disorder qualify for a separate diagnosis of mental illness. Several mental illness-affected population groups have increased risks for developing serious substance problems, including men, individuals with a history of military service and people with chronically limited socioeconomic resources. Dual diagnosis is a classic example of a comorbid health condition. Anyone with comorbid health problems has at least two diagnosable conditions that produce considerably worse results in combination than they would on their own. Compared to people only dealing with diagnosable substance problems or only dealing with diagnosable, non-substance-related mental illness, people with dual diagnosis have less consistent access to appropriate treatment, seek treatment less often, have increased risks for treatment complications, have a harder time achieving and maintaining substance abstinence and have higher chances of dying well below the average age for the general population. Family, Substance Problems and Mental Illness Researchers and public health experts are well aware that family factors play a significant role in determining each individual\u2019s risks for substance problems and mental illness. Some of the risk is genetic, since both substance problems and mental illness tend to pass from generation to generation in certain family bloodlines. However, family-related risk factors also appear over the course of any given person\u2019s early life. For example, the National Institute on Drug Abuse notes that children who live in substance-abusing households or households rife with criminal activity have increased odds of developing alcohol or drug problems as teenagers or adults. In addition, neglected and abused children have increased odds of developing a mental illness as teenagers or adults. Family Factors and Dual Diagnosis In the study published in Addiction, the University of Queensland researchers used a long-term project called the Mater-University of Queensland Study of Pregnancy to identify the family factors that increase a young adult\u2019s chance of being affected by dual diagnosis. A total of 6,703 pregnant women took part in this project. The researchers tracked the health outcomes of these women and their children for the next 21 years; at age 21, the children underwent extensive interviews designed to uncover the presence of diagnosable alcohol problems and separately diagnosable mental illness. The researchers concluded that two family factors increase the chances that a young adult will be affected by dual diagnosis: having a mother who smokes cigarettes and having a mother who displays an unusually low amount of parent-child attachment. The researchers also compared the family factors associated with dual diagnosis to the family factors associated with isolated cases of substance abuse\/addiction and isolated cases of separately diagnosable mental illness. They concluded that children born to fathers with serious alcohol problems have greater risks for dual diagnosis than for isolated substance abuse\/addiction or isolated mental illness. The researchers also identified several non-family-related factors that heighten young adults\u2019 risks for dual diagnosis. These factors include smoking cigarettes, consuming alcohol while still a teenager and having unusual difficulty thinking clearly or maintaining focus or attention. The study\u2019s authors believe that the family-related risks for dual diagnosis in early adulthood may stem at least partly from the problems that some mothers have with substance abuse\/addiction and mental illness. They note that the non-family-related risks they identified for dual diagnosis (smoking, teen drinking and problems with attention and mental clarity) apparently do not have the same impact on the risks for isolated substance problems or isolated mental illness.