Regional cortical thinning of the orbitofrontal cortex in medication-naïve female patients with major depressive disorder is not associated with MAOA-uVNTR polymorphism

MAOA uVNTR Genetic Variant and Major Depressive Disorder: A Systematic Review

Major Depressive Disorder (MDD) is a highly prevalent multifactorial psychopathology affected by neurotransmitter levels. Monoamine Oxidase A (MAOA) influences several neural pathways by modulating these levels. This systematic review (per PRISMA protocol and PECOS strategy) endeavors to understand the MAOA uVNTR polymorphism influence on MDD and evaluate its 3R/3R and 3R* genotypic frequencies fluctuation in MDD patients from different populations. We searched the Web of Science, PubMed, Virtual Health Library, and EMBASE databases for eligible original articles that brought data on genotypic frequencies related to the MAOA uVNTR variant in patients with MDD. We excluded studies with incomplete data (including statistical data), reviews, meta-analyses, and abstracts. Initially, we found 43 articles. After removing duplicates and applying the inclusion/exclusion criteria, seven articles remained. The population samples studied were predominantly Asians, with high 3R and 4R allele frequencies. Notably, we observed higher 3R/3R (female) and 3R* (male) genotype frequencies in the healthy control groups and higher 4R/4R (female) and 4R* (male) genotype frequencies in the MDD groups in the majority of different populations. Despite some similarities in the articles analyzed, there is still no consensus on the MAOA uVNTR variant’s role in MDD pathogenesis.

Orbito-frontal thinning together with a somatoform dissociation might be the fingerprint of PNES

OBJECTIVE

To investigate neuroanatomical changes in patients with psychogenic nonepileptic seizures (PNES) compared to major depressive disorder (MDD) and healthy controls.

METHODS

Forty-two drug-naïve PNES subjects and 25 patients with MDD, matched for demographic characteristics and level of depression (as measured by Beck Depression Inventory-II, BDI-II), were consecutively recruited. Patients performed an extensive neuropsychiatric assessment including: Hamilton Anxiety Rating Scale, Traumatic Experience Checklist, Dissociative Experiences Scale, Toronto Alexithymia Scale and Somatoform Dissociation Questionnaire (SDQ-20). All patients, together with 78 healthy matched controls, underwent 3T brain MRI followed by surface-based morphometry.

RESULTS

Cortical thickness analysis revealed significant cortical thinning in bilateral medial orbitofrontal cortex (OFC) and left rostral anterior cingulate cortex (ACC) in patients with MDD compared to subjects with PNES and controls. Interestingly, increased thickness of the right pars triangularis was found in PNES subjects compared to controls. PNES showed higher scores in SDQ-20 (p < 0.001) compared to MDD, which was corroborated by neuroimaging data, where somatoform dissociation scores correlated with morphological changes in the left medial OFC.

CONCLUSION

Our results show selective cortical thinning over the medial OFC in patients with PNES compared to wider regions of thinning in patients with MDD. Somatoform dissociation was the only psychopathological assessment significantly different in PNES and MDD.

Structural brain measures linked to clinical phenotypes in major depression replicate across clinical centres

Abnormalities in brain structural measures, such as cortical thickness and subcortical volumes, are observed in patients with major depressive disorder (MDD) who also often show heterogeneous clinical features. This study seeks to identify the multivariate associations between structural phenotypes and specific clinical symptoms, a novel area of investigation. T1-weighted magnetic resonance imaging measures were obtained using 3 T scanners for 178 unmedicated depressed patients at four academic medical centres. Cortical thickness and subcortical volumes were determined for the depressed patients and patients' clinical presentation was characterized by 213 item-level clinical measures, which were grouped into several large, homogeneous categories by K-means clustering. The multivariate correlations between structural and cluster-level clinical-feature measures were examined using canonical correlation analysis (CCA) and confirmed with both 5-fold and leave-one-site-out cross-validation. Four broad types of clinical measures were detected based on clustering: an anxious misery composite (composed of item-level depression, anxiety, anhedonia, neuroticism and suicidality scores); positive personality traits (extraversion, openness, agreeableness and conscientiousness); reported history of physical/emotional trauma; and a reported history of sexual abuse. Responses on the item-level anxious misery measures were negatively associated with cortical thickness/subcortical volumes in the limbic system and frontal lobe; reported childhood history of physical/emotional trauma and sexual abuse measures were negatively correlated with entorhinal thickness and left hippocampal volume, respectively. In contrast, the positive traits measures were positively associated with hippocampal and amygdala volumes and cortical thickness of the highly-connected precuneus and cingulate cortex. Our findings suggest that structural brain measures may reflect neurobiological mechanisms underlying MDD features.

Marijuana use and major depressive disorder are additively associated with reduced verbal learning and altered cortical thickness

Marijuana (MJ) use and major depressive disorder (MDD) have both been associated with deficits in verbal learning and memory as well as structural brain abnormalities. It is not known if MJ use by those with MDD confers additional impairment. The goal of this study was to examine unique and combined effects of MDD and MJ use on verbal memory and brain structure. Young adults (n=141) aged 18-25 years with MJ use and no lifetime MDD (MJ, n=46), MDD and no MJ use (MDD, n=23), MJ use and lifetime MDD (MDD+MJ, n=24), and healthy controls without MDD or MJ use (CON, n=48) were enrolled. Participants completed the California Verbal Learning Test, Second Edition (CVLT-II), a measure of verbal learning and memory. A sub-sample of 82 participants also underwent a structural magnetic resonance imaging (MRI) scan. Group differences in CVLT-II performance, cortical thickness, and hippocampal volume were assessed. We found an additive effect of MDD and MJ on memory recall. Only MDD, but not MJ, was associated with poorer initial learning, fewer words recalled, more intrusion errors, and lower percent retention. There was also an additive effect of MDD and MJ use on reduced cortical thickness in the middle temporal gyrus. Findings indicate that MJ use and MDD have additive adverse associations with verbal recall and cortical thickness in the middle temporal gyrus, suggesting that MJ use among those with MDD may be contraindicated. Prospective studies are warranted to determine whether this association may be causal.

Association of cortical thickness with age of onset in first-episode, drug-naïve major depression

OBJECTIVE

We previously showed differences in brain grey matter volume changes between patients with early-onset adult depression (EOD) and late-onset adult depression (LOD). Here, we aim to identify whether cortical thickness (CT) is affected by the age of onset in patients with depression.

METHODS

High-resolution MRI images were obtained for 54 major depressive disorder (MDD) patients with EOD, 58 patients with LOD, 57 young healthy controls (HCs), and 58 aged HCs. Depression severity was assessed using the Hamilton Depression Rating Scale 17-item (HDRS17). Associations between CT of patients and clinical scores were analyzed.

RESULTS

There was a significant main effect of diagnosis for the left rostal anterior cingulate (rACC), right inferior temporal, right lateral orbitofrontal cortex (lOFC), and bilateral pericalcarine. A remarkable onset age-group effect on CT was observed in the rACC and bilateral caudal anterior cingulate (cACC). The diagnosis-by-onset age interaction effect was found in bilateral rACC and right lOFC. Thinning CT in bilateral rACC was observed in EOD patients compared to young HCs. Compared to older HCs, thicker CT in lOFC was seen in the LOD patient group. Compared with the LOD group, the EOD group showed cortical thinning of the right cACC and posterior cingulate cortex (PCC). There were no significant associations between CT in right cACC or PCC with symptom severity or illness duration.

CONCLUSIONS

MDD patients with different age at onset show distinct CT alterations, suggesting potentially divergent pathological mechanisms of EOD and LOD.

Increased Cortical Thickness in Patients With Major Depressive Disorder Following Antidepressant Treatment

Background

Considering the slow-acting properties of traditional antidepressants, an important challenge in the field is the identification of early treatment response biomarkers. Reduced cortical thickness has been reported in neuroimaging studies of depression. However, little is known whether antidepressants reverse this abnormality. In this brief report, we investigated early cortical thickness changes following treatment with sertraline compared to placebo.

Methods

Participants (n = 215) with major depressive disorder were randomized to a selective serotonin reuptake inhibitor, sertraline, or to placebo. Structural magnetic resonance imaging scans were acquired at baseline and one week following treatment. Response was defined as at least 50% improvement in Hamilton rating scale for depression score at week 8. In a vertex-wise approach, we examined the effects of treatment, response, and treatment × response.

Results

Following correction for multiple comparisons, we found a significant effect of treatment, with widespread increase in cortical thickness following sertraline compared to placebo. Clusters with increased thickness were found in the left medial prefrontal cortex, right medial and lateral prefrontal cortex, and within the right parieto-temporal lobes. There were no sertraline-induced cortical thinning, and no significant response effects or treatment × response interactions.

Conclusion

Our findings suggest that cortical thickness abnormalities may be responsive to antidepressant treatment. However, a relationship between these early cortical changes and later treatment response was not demonstrated. Future studies would be needed to investigate whether those early effects are maintained at eight weeks and are associated with enhanced response.

Cortical thickness in major depressive disorder: A systematic review and meta-analysis

Neuroimaging studies assessing neurobiological differences between patients with major depressive disorder (MDD) and healthy controls (HC) are often hindered by small sample sizes and heterogeneity of the patient sample. We performed a comprehensive literature search for studies assessing cortical thickness between patient and control groups, including studies investigating treatment effects on cortical thickness. We identified 34 studies meeting criteria for the systematic review and used Seed-based d Mapping to meta-analyze 24 of those that met additional criteria. Analysis of the full sample of subjects (MDD = 1073; HC = 936) revealed significant thinning in the MDD group in the bilateral orbitofrontal gyrus (BA 11), left pars opercularis (BA 45) and left calcarine fissure/lingual gyrus (BA 17), as well as an area of significant thickening in the left supramarginal gyrus (BA 40). These results support other imaging modalities that report disruptions in various frontal and temporal areas in MDD and identify additional areas in all major cerebral lobes likely to be significant when parsing for biomarkers of treatment or relapse.