CREB1 and Anxiety: CREB knockout mice exhibit increase in anxiety-like behaviors15 and anxiety-like behaviors can be modified by altering CREB function or expression10, 16, 17, 18, 19, and chronic antidepressants administration increases CREB expression, phosphorylation and function in limbic brain structures, including hippocampus and cerebral cortex12, suggesting a role for CREB in anxiety disorders.