MR Spectroscopy in Neuropsychiatry

Neuropsychiatric disorders, covering both psychotic and depressive disorders, but also autism and attention-deficit hyperactivity disorder (ADHD), are characterized by abnormal behavior and brain structure. Accumulating evidence suggests that altered neurochemistry plays a role in these disorders and may have a causal relationship with the observed behavioral and structural abnormalities. To improve the understanding of neurochemical anomalies and (patho)physiological changes in psychiatric conditions, in vivo assessment of the affected tissue, the brain, is wanted and needed. Magnetic resonance spectroscopy (MRS) is a non-invasive technique which allows in vivo assessment of the molecular composition of brain tissues and identification of metabolites involved in physiological and pathological processes, which is otherwise virtually impossible. Only in the last decade with the development of high field MR methodologies, MRS has become sensitive enough for broader use in clinical studies. The implications are many, but proper guidance and elucidation of the pros and cons for the specific methods is needed to optimally exploit the potential.

This Research Topic updates the reader on the possibilities and pitfalls of MRS today and highlights methodologies and applications for the future. A particular focus lies on neuropsychiatric MRS research at ultra-high magnetic fields (UHF) of 7 tesla (T) and up. UHF-MR is beneficial for brain applications in particular and especially MRS gains from higher magnetic field strengths. Aside from the shorter acquisition time to obtain reliable MRS data at UHF, the improved resolution makes assessment of metabolites displaying relatively small resonance peaks obscured by more intense signals on the MR spectrum far easier. Metabolites that are most probably implicated in psychiatric disorders such as glutamate and GABA can now be adequately resolved within a reasonable time-frame. UHF also opens doors for a less complicated investigation of oxidative stress indices such as glutathione and ascorbate. Currently, over 60 research sites worldwide operate a human UHF-MR system and as methodologies are being further developed, this number is rapidly growing.

Researchers are welcome to submit original data from studies using MRS techniques in various settings and investigating different psychiatric disorders, as well as studies focusing on the development of MRS methods for brain research. Submission of review papers and recommendations for future research are also highly encouraged.

The aim of this Research Topic is to provide researchers and clinicians with a one-stop-shop on the current status of MRS studies in neuropsychiatry, as well as future directions and possible clinical implications for the modality.