OBJECTIVE: This study was carried out to compare the efficacy of lithium
carbonate with that of valproate in acute mania and to determine whether
pretreatment clinical characteristics, such as the presence of a mixed
affective state, might predict a differential response to the two drugs.
METHOD: Twenty-seven patients meeting DSM- III-R criteria for acute manic
episodes underwent a 3-week, randomized, double-blind, parallel-groups
trial of treatment with lithium carbonate or valproate. Symptom severity
was measured by using the Schedule for Affective Disorders and
Schizophrenia, change version (SADS-C), the Global Assessment Scale (GAS),
and the Brief Psychiatric Rating Scale (BPRS). Drug effects were compared
by using repeated measures analysis of variance (ANOVA). RESULTS: At the
end of the study, nine of 14 patients treated with valproate and 12 of 13
patients treated with lithium had responded favorably, as measured by
changes in the SADS-C mania, BPRS, and GAS scores. Elevated pretreatment
SADS-C depression scores were associated with good response to valproate.
ANOVA revealed a significant interaction between drug and mixed affective
state with respect to treatment response. CONCLUSIONS: Lithium and
valproate were both effective in improving manic symptoms, and lithium was
slightly more efficacious overall. Unlike the case with lithium, favorable
response to valproate was associated with high pretreatment depression
scores. Therefore, treatment with valproate alone may be particularly
effective in manic patients with mixed affective states.