A magnetization transfer imaging study of young and middle ⁃age patients with major depressive disorder

Abstract

Objective To explore the cerebral magnetization transfer ratio (MTR) changes in young and middle⁃age patients with major depressive disorder (MDD) and its correlation with the disease duration. Methods Thirty MDD patients and 30 healthy controls took part in the whole study. Patients were diagnosed by experienced psychiatrists according to Diagnostic and Statistical Manual of Mental Disorders Fouth Edition (DSM ⁃ Ⅳ) criteria (American Psychiatric Association, 1994). Severity of depression was assessed by 17⁃item Hamilton Depression Rating Scale (HAMD) and only patients who scored 18 or higher were included. Healthy controls were individually matched with the patients for age, sex, handedness and education. Magnetization transfer imaging (MTI) was acquired by using a 3.0T Siemens magnetic resonance imaging (MRI) system. MTR map calculation, normalization, smoothing and statistical analysis were all carried out in the software Statistical Parametric Mapping (SPM). A 2⁃sample t ⁃test was used for group comparison and a Pearson correlation was used to examine the relationship between MTR and disease duration in MDD patients. Results In SPM, we set the cluster level P < 0.05 as the statistical significance threshold. Compared with normal controls, no brain regions in MDD patients with significant changed MTR were found. However, significant negative correlation was observed between the disease duration of MDD subjects and their MTR in the left prefrontal, parietal and temporal areas, and bilateral anterior cingulate gyrus. Further analysis revealed that in comparison with matched controls, MTR was significantly lower in the left middle frontal gyrus, bilateral middle cingulate cortex and right anterior lobe of cerebellum in patients with longer disease duration (> 60 weeks); and MTR was higher in the left middle frontal gyrus, tempo ⁃ occipital boundary, bilateral anterior cingulate cortex and adjacent white matter in patients with shorter disease duration (≤ 60 weeks). Conclusion MDD presents cerebral MTR changes in different pattern along with disease progression, which may implicate the needs of longitudinal imaging study for MDD, and particularly the effect of long term antidepressant treatment exerting on brain structure and function should be emphasized.

DOI：10.3969/j.issn.1672-6731.2011.03.008