Mood disorders like bipolar disorder have shown structural changes in the brain, including cell loss and alterations in the corticolimbic regions. These findings, from post-mortem studies and brain imaging, have led to a better understanding of the mechanisms behind treatments. Mood stabilizers like lithium and valproic acid, along with antidepressants and electroconvulsive therapy, activate intracellular signaling pathways that promote neurogenesis and synaptic plasticity, paving the way for more effective therapies.

While traditional treatments focused on synaptic neurotransmission, such as serotonin reuptake inhibitors, some mood stabilizers like lithium and valproic acid do not directly affect neurotransmission. Instead, they work through other cellular pathways that promote changes in brain structure and function. Combined with the discovery of several genetic loci associated with bipolar disorder, this has enhanced the understanding of its pathophysiology, which could improve therapeutic strategies and, in the long run, the quality of life for those affected.