A commentary notes that this study provides clear evidence of the potential risks of long-term lithium therapy and discusses how these hazards can be navigated, especially in light of bipolar disorder typically emerging at a young age and requiring lifelong treatment. The commentator suggests that maintenance of lithium concentrations at the lower end of the therapeutic range (i.e. 0.6 mmol/L) can reduce adverse outcomes linked to lithium treatment but it is a delicate balancing act between achieving plasma lithium concentrations high enough to be efficacious, but low enough to avoid toxicity. He adds that although the simple pharmacokinetics of lithium in plasma are helpful, that within the brain is more complex because the blood–brain barrier insulates the brain from rapid changes in plasma lithium concentration and facilitates its accumulation in neural tissues, which can be neurotoxic. He notes that as the movement of lithium between plasma, cerebrospinal fluid, and brain tissue is not fully understood, future research will need to examine the effects of different doses and duration of lithium treatment on concentrations within these various compartments.