Researchers at the University of Oulu’s Research Unit of Clinical Medicine and Oulu Business School have examined how symptoms of adolescent ADHD (attention-deficit/hyperactivity disorder) and oppositional defiant disorder (ODD) are related to adult income.
The study found that the symptoms are not directly linked to income levels in adulthood. Instead, the impact is seen indirectly, through education and other psychiatric disorders.
The effect was strongest among individuals with symptoms of both ADHD and ODD: their incomes were on average 25 per cent lower through the pathway of education and 18 per cent lower through other psychiatric disorders.
The study used data from the Northern Finland Birth Cohort 1986, which includes nearly 9,500 participants. When they were 16 years old, their parents assessed their ADHD and ODD symptoms using a questionnaire. In addition, national registers were used to obtain information on education, annual income, psychiatric disorders and background factors.
ODD is a common comorbid disorder of ADHD, occurring in about 30 per cent of those diagnosed with ADHD. The large-scale data also made it possible to examine the independent effects of ODD symptoms – an area where research has previously been scarce and partly contradictory.
ADHD alone does not determine income level
According to Sampo Seppä, the lead author of the study, the results are encouraging: “Symptoms of adolescent ADHD and ODD were not in themselves associated with lower income levels in adulthood,” Seppä explains.
However, his earlier research has shown that ADHD and ODD symptoms impair school performance during adolescence, lower educational attainment in adulthood, and increase the risk of unemployment and sickness absence.
“These new findings add to our understanding of why young people with ADHD tend to fare worse in working life on average. The results may help reduce the stigma associated with ADHD and strengthen the belief that with the right support, young people can succeed in working life just like anyone else,” Seppä says.
The study also highlights the importance of preventive services.
“I hope this research will help to increase appreciation of investments in education and mental health services, so that the consequences of neurodevelopmental disorders can be reduced at the population level,” Seppä concludes.