A study conducted in Finland is demonstrating how ADHD symptoms can persist from childhood into adulthood with negative consequences if left untreated. The study spanned four decades and involved 1,196 individuals who were followed from birth to age 40. It is a rare look at the progression of ADHD symptoms.
One challenge the researchers faced was that when data collection began in the early 1970s, our understanding of mental health conditions was much less advanced, and ADHD as we know it today wasn’t even a diagnosis commonly being made. So the study team used behavior reports, interviews and assessments of attention problems, which they were able use to make reasonably accurate retrospective evaluations of ADHD. Using that data, they divided study participants into three groups:
- Individuals who would have qualified for an ADHD diagnosis
- Individuals who had sub-threshold ADHD symptoms not quite meeting the clinical cutoff
- Individuals without ADHD symptoms
The researchers invited participants back for an ADHD assessment and series of surveys at age 40. Altogether, the study ended with 318 participants who still met the eligibility requirements and agreed to do the followup survey. Of those, 37 had had childhood ADHD and 64 had been children with sub-threshold symptoms.
- 20% of adults with childhood ADHD still exhibited high levels of ADHD symptoms at 40.
- 25% of adults with childhood ADHD still had executive function challenges at 40.
- Academic underachievement in childhood led to a permanently lower educational track.
- Children with ADHD had more issues with drug use at age 40.
- Individuals with sub-threshold ADHD symptoms did not appear to have negative outcomes in adulthood
While there can be problems with a retrospective diagnosis of ADHD, the patterns discovered by the researches are consistent with what we know about ADHD today. The study findings underscore the importance of diagnosing and managing both childhood and adult ADHD.