Attention-deficit/hyperactivity disorder (ADHD) is highly heritable and the most common
neurodevelopmental disorder in childhood. In recent decades, it has been appreciated
that in a substantial number of cases the disorder does not remit in puberty, but
persists into adulthood. Both in childhood and adulthood, ADHD is characterised by
substantial comorbidity including substance use, depression, anxiety, and accidents.
However, course and symptoms of the disorder and the comorbidities may fluctuate and
change over time, and even age of onset in childhood has recently been questioned.
Available evidence to date is poor and largely inconsistent with regard to the predictors
of persistence versus remittance. Likewise, the development of comorbid disorders
cannot be foreseen early on, hampering preventive measures. These facts call for a
lifespan perspective on ADHD from childhood to old age. In this selective review,
we summarise current knowledge of the long-term course of ADHD, with an emphasis on
clinical symptom and cognitive trajectories, treatment effects over the lifespan,
and the development of comorbidities. Also, we summarise current knowledge and important
unresolved issues on biological factors underlying different ADHD trajectories. We
conclude that a severe lack of knowledge on lifespan aspects in ADHD still exists
for nearly every aspect reviewed. We encourage large-scale research efforts to overcome
those knowledge gaps through appropriately granular longitudinal studies.
