Title:
[A review of the effects of lithium on cognitive functions: Effects on the neuropsychiatrically challenged CNS].

Abstract:
Recent data attribute neuroprotective and neurotrophic actions to lithium, leading to expectations  of cognitive enhancement action. This hypothesis is at odds with the predominant view of clinical  psychiatr y  which,  on  the  basis  of  older  clinical  data  as  well  as  on  subjective  reports  of  lithiumtreated patients, associates lithium with cognitive blurring and specific memory deficits. Review of  the older data and their integration with more recent clinical and experimental work on the primary  effects of lithium on cognitive functioning led us to two central conclusions: (a) Data on the primary cognitive effects of lithium, considered in their entirety, do not support a picture of serious or  long-lasting cognitive decline. On the contrary, recent evidence suggests cognitive enhancement  under certain conditions. (b) The conditions which appear to promote the emergence of cognitive  enhancement under lithium are conditions of challenge to the cognitive systems, such as increased  task difficulty resulting in deterioration in the performance of untreated controls. We are suggesting that alternative challenges to cognitive functioning, which therefore would facilitate the emergence of lithium's cognitive enhancement action, include biological insults to the central nervous  system (CNS). This second part of our review of the cognitive effects of lithium therefore focuses on  studies of its action on cognitive dysfunction associated with functional or biological challenge to  the CNS, such as stress, trauma, neurodegenerative and psychiatric disorders.