After over 50 years of use, lithium-salts remain the first-line therapy for the management of bipolar disorder. Throughout this period, the potential for lithium salts has been extensively studied and numerous data favor its use in the treatment of neurodegenerative disorders such as Alzheimer’s disease (AD). We reviewed existing evidence gathered from clinical case reports and studies on the effect of lithium on neuropsychological symptoms of AD and as a disease-modifying treatment acting on cognitive symptoms. The review summarizes the molecular pathways, involving GSK-3β inhibition and neuroprotection, through which lithium is proposed to exert its effect. Limitations to its current use in AD are discussed and future perspectives as a potential treatment option for AD are considered in regard to ongoing clinical trials using different forms of lithium.