A Review of Lithium Effects on Inhibitory Control in Executive Tasks

Objective: Lithium counteracts impulsivity and aggression in affective disorders, two emotion-related facets of inhibitory control. This raises the question of whether lithium also affects inhibitory processes in the cognitive domain. Methods: This narrative review examines experimental groups of patients receiving lithium, either as monotherapy or as part of multitherapy, compared with patients on other medications or healthy controls. Results: Patients taking lithium alongside other medications performed worse than healthy controls on the Trail Making Test B, Stroop Color-Word Test, and Wisconsin Card Sorting Test. Similarly, those on lithium monotherapy also underperformed compared to healthy controls on the Trail Making Test B and Stroop Color-Word Test. However, their performance on the Wisconsin Card Sorting Test was less impaired. Discussion: The inhibitory processes assessed by the Trail Making Test B and Stroop Color-Word Test appear to be particularly susceptible to the effects of lithium. Conclusion: The apparent vulnerability in performance on the Trail Making Test B and Stroop tests needs to be confirmed with studies that include placebo controls.