Does lithium therapy protect against the onset of dementia?

Lithium compounds might theoretically play a role in preventing dementia by inhibiting formation both of beta amyloid and hyper phosphorylated tau protein. We carried out a case-control study to assess any possible clinical effects of lithium therapy on the diagnosis of dementia, using data from the General Practice Research Database, which collects routine data from primary care patients in the UK. Patients who received lithium had a higher risk of a diagnosis of dementia compared with those who did not (adjusted odds ratio 1.8, 95% CI 1.1-2.8). There was a trend toward increasing risk with increasing numbers of lithium prescriptions. This evidence does not support the use of lithium for preventing dementia.