Objective: To evaluate the efficacy of lithium in the treatment of acute ma
nia.
Method: Systematic overview of the literature and meta-analysis of randomis
ed controlled trials. Estimation of (i) the differences in the reduction in
mania severity scores, and (ii) the ratio and difference in improvement re
sponse rates.
Results: A total of 658 patients from 12 trials were included. Treatment pe
riods ranged from 3 to 4 weeks. The response rate ratio for lithium against
placebo was 1.95 (95%CI 1.17-3.23). The mean number needed to treat was fi
ve (95%CI 3-20). Patients were twice as likely to obtain remission with lit
hium than with chlorpromazine (rate ratio = 1.96, 95%CI 1.02-3.77). The mea
n number needed to treat was four (95%CI 3-9). Neither carbamazepine nor va
lproate was more effective than lithium. The response rate ratios were 1.01
(95%CI 0.54-1.88) for lithium compared to carbamazepine and 1.22 (95%CI 0.
91-1.64) for lithium against valproate. Haloperidol was no better than lith
ium on the basis of improvement based on assessment of global severity. The
differences in effects between lithium and risperidone were -2.79 (95%CI -
4.22 to -1.36) in favour of risperidone with respect to symptom severity im
provement and -0.76 (95%CI -1.11 to -0.41) on the basis of reduction in glo
bal severity of disease. Symptom and global severity was as well controlled
with lithium as with verapamil. Lithium caused more side-effects than plac
ebo and verapamil, but no more than carbamazepine or valproate.
Conclusion: The clinical trial evidence suggests that lithium should remain
the first line treatment for acute mania.