[A review of the effects of lithium on cognitive functions: primary effects]

Lithium has well-documented beneficial effects on the acute and prophylactic treatment of bipolardisorder. Its value as an add-on treatment of unipolar depression is also established. Additionally, amultitude of recent experimental data indicate that lithium has pronounced neuroprotective andneurotrophic action: given this neuroprotective profile, it is reasonable to expect this substanceto have beneficial effects on cognitive functioning. However, the hypothesis that lithium may act Lithium has well-documented beneficial effects on the acute and prophylactic treatment of bipolar disorder. Its value as an add-on treatment of unipolar depression is also established. Additionally, a multitude of recent experimental data indicate that lithium has pronounced neuroprotective and neurotrophic action: given this neuroprotective profile, it is reasonable to expect this substance to have beneficial effects on cognitive functioning. However, the hypothesis that lithium may act as a cognitive enhancer is at odds with clinical data which suggest that it has a "cognitive blurring" action and a specific, detrimental effect on memory. The aim of this review was to re-examine the findings of older clinical and experimental studies and integrate them with recent clinical and experimental data, addressing the primary effects of lithium on learning, memory, attention and executive functioning. On the basis of this integration we suggest that the relevant findings do not uphold the picture of persistent cognitive compromise attached to lithium treatment. Furthermore, based on recent data from our own and other laboratories, we propose the hypothesis that lithium may, under specific circumstances, act as a cognitive enhancer.