Subtypes of depression characterized by different cognitive decline and brain activity alterations
- “Depression is characterized by the heterogeneity in anti-depressant treatment response and clinical outcomes. Cognitive impairment may be one of the more practically important aspects of depression.”
- “A new approach was to identify neuropsychologically derived depression subtypes based on the trajectory of neuro-cognition such as intelligence quotient (IQ) change.
- “IQ change was used to delineate the patterns of neuropsychological heterogeneity within a large dataset consisting of 131 patients with major depressive disorder (MDD) and 165 healthy controls (HCs).”
- “Neurocognitive results from CANTAB and 3 T resting-state fMRI data were compared among the subgroups identified. IQ change heterogeneity identified two subgroups within the MDD group: preserved IQ (PIQ) and deteriorated IQ (DIQ) in MDD. The DIQ subgroup was marked by poorer functioning across multiple cognition domains, including increased impairments in motor speed, cognitive flexibility, and catastrophic thinking when compared to PIQ and HCs. Moreover, cognitive performance of patients with DIQ was correlated with IQ decline. Also, increased brain activity of anterior cingulate cortex and medial prefrontal cortex was found in DIQ but not in PIQ and HCs.”
- “IQ-based subgroups of depression may be differentially associated with the extent of neurocognitive impairment and brain activities, which suggests that classifying the cognitive heterogeneity associated with depression may provide a platform to better characterize the neurobiological underpinnings of the disease.”
Characterization of brain functional connectivity in treatment-resistant depression
- “Objective: To characterize the functional connectivity (FC) of target brain regions for deep brain stimulation (DBS) in patients with treatment-resistant depression (TRD), and to evaluate its gender and brain lateralization dependence.”
- “Methods: Thirty-one TRD patients and twenty-nine healthy control (HC) subjects participated. FC of subcallosal cingulate gyrus (SCG), ventral caudate (VCa), nucleus accumbens (NAc), lateral habenula (LHb), and inferior thalamic peduncle (ITP) were evaluated using resting-state fMRI. FC was characterized by calculating the nodal ‘degree’, a major feature of the graph theory.”
- “Conclusion: Our findings demonstrate the ability of degree to characterize brain FC and identify the regions with abnormal activities in TRD patients. This implies that the degree may have the potential to be used as an important graph-theoretical feature to further investigate the mechanisms underlying TRD, and consequently along with other diagnostic markers, to assist in the determination of the appropriate target region for DBS treatment in TRD patients”
Neuronal underpinnings of cognitive impairment in bipolar disorder: A large data-driven functional magnetic resonance imaging study
- “Objectives: Cognitive impairment occurs in approximately 50% of remitted patients with bipolar disorder (BD). However, there exists no treatment with replicated and robust efficacy on cognition in BD. This is partially due to limited insight into the neuronal underpinnings of cognitive impairment in these patients.”
- “This is the first study to investigate neuronal underpinnings of cognitive impairment in a large functional magnetic resonance imaging (fMRI) dataset comparing neural activity patterns between distinct neurocognitive subgroups of partially or fully remitted patients with BD.”
- Methods: Patients (n=153) and healthy controls (HC) (n=52) underwent neuropsychological assessment and fMRI, during which they performed a verbal N-back working memory (WM) task.
- Results: Cognitively impaired patients displayed WM-related hypo-activity in left dorsolateral prefrontal cortex and frontal and parietal regions within a cognitive control network (CCN) as well as hyper-activity in the default mode network (DMN) compared to cognitively normal patients. In contrast, cognitively normal patients only exhibited hypo-activity within a small cluster in the superior frontal gyrus relative to HC.
- “Conclusions: Cognitive impairment in BD seems to originate from a failure to recruit key regions in the CCN and to suppress task-irrelevant DMN activity during cognitive performance. These results highlight modulation of aberrant dorsal prefrontal and DMN activity as a putative target for pro-cognitive treatment in BD.”
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The Treatment Scout website helps people find effective inpatient and residential care. It can also help you explore other intensive care options for mental health, addiction, etc. Find out more at http://www.treatmentscout.com/
NAMI Montana’s has a resource guide for every county in Montana. Check it out at https://namimt.org/montana-county-mental-health-resource-guides/
