Peroxisome Proliferator-Activated Receptors (PPARs) are a family of nuclear receptors whose activation modulates the gene expression that underlies both the glucid-lipid and the inflammation pathways. While many PPARs agonists have been used for years as medication for metabolic disorders, an increasing attention is being currently dedicated to these drugs for inflammation-related pathologies. Within the psychiatric field, it has recently appeared that inflammatory processes are highly suspected in the pathophysiology of several important disorders, such as schizophrenia and mood disorders. By their anti-inflammatory properties, PPARs might have a disease-modifying action that could help in improving the outcome of patients. Furthermore, recent data suggest that PPARs could also modulate the expression of some neurotransmission factors. Therefore, PPARs may directly modify the information processing, and have a potential symptomatic action on several psychiatric disorders. At last, PPARs action of metabolic regulation could have a role on corrective or even preventive strategies against the metabolic adverse events that are commonly observed with some current psychiatric medications, notably antipsychotics. This triple potential action profile of PPARs modulators is investigated in this article, successively for schizophrenia spectrum disorders and mood disorders. Theoretical involvements of PPARs are also discussed for the treatment of Post- Traumatic Stress Disorder and Personality Disorders. At the time of the emerging concept of psychoneuroimmunology, PPARs open original therapeutic prospects for the psychiatric research.