An Old Drug, Lithium, May Help Prevent Alzheimer’s

Lithium is an established treatment for the manic phases of bipolar disorder, and there’s good evidence of its anti-suicidal properties.  Moreover, Alzheimer’s disease rates are reportedly reduced in patients with bipolar disorder on lithium.  Researchers at the University of Sao Paulo, Brazil, have conducted a small study on patients with mild cognitive impairment (MCI), and report their findings in the British Journal of Psychiatry.

Forty-five patients with memory-centered MCI were randomly assigned to take lithium – dosed to a blood level of 0.25 to 0.5 mmol/L, tested weekly – or a placebo, for 12 months.  (This dosage of lithium was lower than that normally used in bipolar disease.)  A whole battery of cognitive tests were done at intervals, in order to assess conversion from MCI to Alzheimer’s disease.  An important measurement, however, was modification of concentrations of different tau proteins in the spinal fluid.

The number of conversions from MCI to Alzheimer’s was higher in the placebo group (7/20) than in the lithium group (4/21), but this difference wasn’t statistically significant, and could therefore have occurred by chance alone.  These 11 ‘converters’ had the typical Alzheimer’s disease ‘signature’ in the spinal fluid, i.e. a higher concentration of T-tau and P-tau, as compared with non-converters.

After 12 months, all the participants had a decline in memory and cognitive function tests; however, the decline was significantly smaller in the lithium-treated group in two of the major cognitive tests used.  Lithium treatment was also associated with significantly lower P-tau in spinal fluid, whereas this protein was increased in placebo patients.  Adverse effects were mild, short-lived, and similar in both treatment groups.

These results are sufficient to call for larger studies to replicate, or refute, the benefits of lithium in such patients.  It’s hard to get such studies done, however, because there’s insufficient patent protection for lithium to make it a worthwhile research project for most pharmaceutical companies.  But, if confirmed, the above findings shouldn’t be ignored; lithium may offer a new direction for research into more powerful MCI-modifying agents.