Psychiatric disorders biochemical pathways unraveled by human brain proteomics

Approximately 25 % of the world population is affected by a mental disorder at some point in their life. Yet, only in the mid-twentieth century a biological cause has been proposed for these diseases. Since then, several studies have been conducted toward a better comprehension of those disorders, and although a strong genetic influence was revealed, the role of these genes in disease mechanism is still unclear. This led most recent studies to focus on the molecular basis of mental disorders. One line of investigation that has risen in the post-genomic era is proteomics, due to its power of revealing proteins and biochemical pathways associated with biological systems. Therefore, this review compiled and analyzed data of differentially expressed proteins, which were found in postmortem brain studies of the three most prevalent psychiatric diseases: schizophrenia, bipolar disorder and major depressive disorders. Overviewing both the proteomic methods used in postmortem brain studies, the most consistent metabolic pathways found altered in these diseases. We have unraveled those disorders share about 21 % of proteins affected, and though most are related to energy metabolism pathways deregulation, the main differences found are 14-3-3-mediated signaling in schizophrenia, mitochondrial dysfunction in bipolar disorder and oxidative phosphorylation in depression.