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Updated: Apr 19, 2026

The Tail Suspension Test
Published on: January 28, 2012
Acute administration of lithium, but not valproate, modulates cognitive judgment bias in rats
Rafal Rygula1, Joanna Golebiowska, Jakub Kregiel
1Affective Cognitive Neuroscience Lab, Department of Behavioral Neuroscience and Drug Development, Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343, Krakow, Poland, rygula@gmail.com.
Rationale And Objectives:
Both valproic acid (VPA) and lithium (LI) are well-established treatments for therapy of intense and sustained mood shifts, which are characteristics of affective disorders, such as bipolar disorder (BP). As mood and cognitive judgment bias have been found to be strongly interrelated, the present study investigated, in an animal model, whether acute treatment with VPA or LI could affect cognitive judgment bias.
Methods:
To accomplish this goal, two groups of rats received single injections of either VPA or LI after initial behavioral training and were subsequently tested with the ambiguous-cue interpretation (ACI) test. Both drugs were administered in three doses using the fully randomized Latin square design.
Results:
VPA (100, 200, and 400 mg/kg) had no significant effect on the interpretation of the ambiguous cue. LI at the lowest dose (10 mg/kg) had no effect; at an intermediate dose (50 mg/kg), it significantly biased animals towards positive interpretation of the ambiguous cue, and at the highest dose (100 mg/kg), it impaired the ability of animals to complete the test.
Conclusion:
To our knowledge, this is the first study demonstrating lithium's effects on increased optimistic judgment bias. Future studies may focus on the ability of putative pharmacotherapies to modify the cognitive judgment bias dimension of patients at risk for bipolar disorder or depression.

