Neurocognition in bipolar disorders--a closer look at comorbidities and medications

The last decade has witnessed a growing interest in the neuropsychological study of bipolar disorder (BD). This chronic mood disorder is associated with persistent neurocognitive impairments even during periods of euthymia, particularly in the broad domains of attention, verbal memory and executive functions. More interestingly, cognitive dysfunction seems to predict a poorer functional outcome among BD patients and thus represents an important target for future therapies. The aetiology of cognitive dysfunction is probably multifactorial, including gene-environment interactions with potentially confounding variables as well. Drug-induced cognitive adverse effects represent an important and difficult to examine confounder. This review provides an overview of selected aspects of neurocognition in bipolar disorder with a focus on the relative contributions of medications as well as medical and psychiatric comorbid conditions to cognitive dysfunction. Finally, recommendations for future research in the field are provided including collaborative studies with larger samples, observational follow-up studies, as well as randomized clinical trials comparing head-to-head the neurocognitive impact of different medications.