A study of over a million people in Sweden found that individuals whose parents had a substance use disorder face an increased risk of receiving a psychiatric diagnosis. The risk was found to be 80% higher for males and 56% higher for females. The findings were published in the Journal of Psychiatric Research.
Substance use disorders are a group of conditions involving the recurrent use of substances, like drugs or alcohol, despite harmful consequences to physical, mental, or social health. These disorders are characterized by an inability to control usage, intense cravings, and continued use despite negative impacts on relationships, work, or health.
While it is well-known that substance use disorders have negative consequences for the individual, research has recently begun to focus on the effects of these disorders on others, known as the “harm to others” framework. A key area of these studies is the impact on children growing up with parents affected by substance use disorders. These children have been found to have lower academic achievement than their peers whose parents do not have such disorders, as well as an increased risk of various mental health and developmental issues.
Study author Hélio Manhica and his colleagues aimed to explore the mental health risks for children of parents with substance use disorders in greater detail. They also sought to determine whether these risks differ between males and females and if certain periods in childhood or adolescence are particularly critical in relation to exposure to parental substance use disorder (i.e., periods that influence the overall risk of developing psychiatric disorders).
The study included 1,093,225 individuals born between 1981 and 1990 who resided in Sweden during their childhood and adolescence. Study participants were followed from birth until a maximum age of 25. The study excluded individuals who died or received a psychiatric diagnosis before 18 years of age.
Researchers tracked whether either parent of a participant had been diagnosed with an alcohol or drug use disorder, as well as whether the participant had been diagnosed with any psychiatric disorder. Additional data included participants’ origin (native Swedish, youth migrants, or offspring of migrants), place of birth, relative poverty, parental psychiatric diagnoses other than substance use disorders, and participants’ school grades.
Results showed that around 4% of participants were exposed to parental substance use disorder during childhood and adolescence, and approximately 14% received a psychiatric diagnosis between 18 and 35 years of age.
Participants with parents who had substance use disorders were almost twice as likely to receive a psychiatric diagnosis. The risk was 116% higher for men and 80% higher for women. However, when researchers adjusted for factors such as relative poverty, year of birth, participants’ origin, and the size of the settlement they lived in, the increased risk was somewhat lower.
After these adjustments, men with parents affected by substance use disorder were 80% more likely to receive a psychiatric diagnosis compared to their peers whose parents did not have such a disorder. This risk was 56% higher in women with affected parents.
Individuals exposed to parental substance use disorder between birth and age 12 faced a higher risk of developing psychiatric disorders compared to those exposed between ages 13 and 18.
When examining specific diagnoses, individuals exposed to parental substance use disorder were approximately 2.5 times more likely to develop substance use disorders themselves and around 2.2 times more likely to develop externalizing disorders (e.g., aggression, impulsivity, rule-breaking).
“Individuals who were exposed to parental SUD [substance use disorder] before the age of 18 years had an increased risk for subsequent psychiatric disorders. These risks seemed to be somewhat higher among males and among those exposed during childhood when compared to during adolescence,” the study authors concluded.
The study sheds light on the link between parental substance use disorder and the risk of psychiatric disorders in offspring. However, it should be noted that the study’s design does not allow for cause-and-effect conclusions. While it is possible that living with parents affected by substance use disorder increases the risk of psychiatric disorders in children, this increased risk may also stem from genetic factors shared between parents and children, or from shared environmental and living conditions.
The paper, “Parental substance use disorders and psychiatric conditions in offspring: a Swedish population-based cohort study with over 1000000 individuals,” was authored by Hélio Manhica, Andreas Lundin, Peter Wennberg, and Anna-Karin Danielsson.