Mood disorders: treatment-induced changes in brain neurochemistry and structure

Continuing advances in neuroimaging technology as well as postmortem examinations have enabled researchers to begin to accumulate substantial evidence suggesting that chronic mood disorders may be associated with actual structural and neurochemical changes within the brain. There is emerging evidence to suggest that various treatment modalities may also induce measurable changes within the brain detectable with specialized neuroimaging techniques, which may be responsible for their clinical therapeutic effects. One such specialized neuroimaging technique, magnetic resonance spectroscopy (MRS), is briefly reviewed. Included is an overview of basic MRS technology and a review of its application in the study of chronic mood disorders to date. We review our recent studies investigating neurochemical changes induced by the mood stabilizer, lithium, in the treatment of bipolar disorder (BPD). Finally, in view of accumulating evidence suggesting a neuronal atrophy and cell death hypothesis for depression, we discuss the potential use of MRS to evaluate pharmacologic interventions for important potential neurotrophic and neuroprotective effects on the adult human brain.