Magnetic resonance spectroscopy in anxiety disorders

Objective: Magnetic resonance spectroscopy (MRS) is a non-invasive in vivo method used to quantify metabolites that are relevant to a wide range of brain processes. This paper briefly describes neuroimaging using MRS and provides a systematic review of its application to anxiety disorders. Method: A literature review was performed in the PubMed, Lilacs and Scielo databases using the keywords spectroscopy and anxiety disorder. References of selected articles were also hand-searched for additional citations. Results: Recent studies have shown that there are significant metabolic differences between patients with anxiety disorders and healthy controls in various regions of the brain. Changes were mainly found in N-acetylaspartate, which is associated with neuronal viability, but some of them were also seen in creatine, a substance that is thought to be relatively constant among individuals with different pathological conditions. Conclusions: MRS is a sophisticated neuroimaging technique that has provided useful insights into the biochemical and neurobiological basis of many anxiety disorders. Nevertheless, its utilization in some anxiety disorders is still modest, particularly social phobia and generalised anxiety. Although it is an extremely useful advance in neuroimaging, further research in other brain areas and patient populations is highly advisable.