The mineralocorticoid hormone aldosterone has been investigated almost exclusively with respect to cardiovascular function, as the main effects of aldosterone are related to water-electrolyte balance and the control of the blood pressure. This overview is focused on less traditional and long-time neglected effects of aldosterone on the brain and behavior. Preclinical studies by our research group brought evidence on causal relationships between aldosterone and anxiety as well as aldosterone and depression-like behavior. Aldosterone was found to be anxiogenic and depressogenic in a rat model. Preclinical studies also indicate that aldosterone may be an early marker of depression onset. Aldosterone is known to be an important component of the stress response, and we have shown that its role is particularly important during early postnatal period in pups. Studies in patients with major depressive disorder revealed that an unfavorable therapy outcome is predicted by a higher salivary aldosterone/cortisol ratio. Our clinical studies showed that salivary aldosterone concentrations reflect the severity, duration of the depressive episode, and treatment outcome in patients with major depressive disorder. Moreover, the patients with depression fail to exert known daily rhythmicity of aldosterone release.

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