Background: Attention deficit hyperactivity (ADHHD) disorder is a neurodevelopmental disorder
characterized by inattention, hyperactivity, disruptive behaviour, and impulsivity. Albeit considered
typical of children for a long time, the persistence of ADHD symptoms in adulthood gained increasing
interest during the last decades. Indeed, its diagnosis, albeit controversial, is rarely carried out even
because ADHD is often comorbid with several other psychiatric diosrders, in particular with bipolar
disorders (BDs), a condition that complicates the clinical picture, assessment and treatment.
Aims: There aim of this paper was to systematically review the scientific literature on the
neurobiological, clinical features and current pharmacological management of ADHD comorbid with BDs
across the entire lifespan, with a major focus on the adulthood.
Discussion: The pharmacology of ADHD-BD in adults is still empirical and influenced by the individual
experience of the clinicians. Stimulants are endowed of a prompt efficacy and safety, whilst non-
stimulants are useful when a substance abuse history is detected, although they require some weeks in
order to be fully effective. In any case, an in-depth diagnostic and clinical evaluation the single individual
Conclusions: The comorbidity of ADHD with BD is still a controversial matter, as it is the notion of adult
ADHD as a distinct nosological category. Indeed, some findings highlighted the presence of common
neurobiological mechanisms and overlapping clinical features, although disagreement does exists. In any
case, while expecting to disentangle this crucial question, it is essential a correct management of this
comorbidity that requires the co-administration of mood stabilizers. Further controlled clinical studies in
large samples of adult ADHD-BD patients appear extremely urgent in order to better define possible
therapeutic guidelines, as well as alternative approaches for this potentially invalidating condition.