Frontostriatal deficits in unipolar major depression
ABSTRACT Recent accounts of major depression have tended to focus on dysfunction of frontothalamic-striatal reentrant circuits as a possible source of the disorder. Evidence of frontostriatal involvement in unipolar major depression from lesion and neuropsychological studies, and functional and structural imaging studies is examined. The high incidence of depressive symptomatology following left frontal and basal ganglia lesions implicate these as possible sites of dysfunction. Neuropsychological evidence indicates similar deficits in patients with major depression, perhaps with dorsolateral prefrontal deficits most prominent. Structural imaging studies report frontal and basal ganglia (BG) abnormalities particularly in cases of late-age onset depression. Resting state functional imaging studies show deficits in dorsolateral, anterior cingulate (medial frontal), and BG structures. Activation imaging studies show less consistent evidence of dorsolateral deficit, while anterior cingulate deficit is more consistently demonstrated. Variability in findings across studies may reflect differences between subtypes of depression and differences in methodology. Possible involvement of the BG in the psychomotor retardation of depression is examined. It is concluded that, while there is evidence of frontostriatal deficit in major depression, the exact nature of such deficits is uncertain. Issues such as component vs. system dysfunction need to be addressed.
- SourceAvailable from: Poppy L A Schoenberg
[Show abstract] [Hide abstract]
- "ence Increased left - intra - hemispheric coherence ( F3 – P3 ) was specific to the MBCT group , compared to right - hemi - spheric coherence ( F4 – P4 ) in the WL . These findings suggest MBCT enhanced fronto - parietal connectivity within the left - hemisphere , where left frontal hypoactivity is a consistent finding in MDD ( Ohta et al . 2008 ; Rogers et al . 1998 ( review ) ; Bajulaiye and Alexopoulos 1994 ) . Moreover , enhanced long - range fronto - parietal coherence was exclusive to the α - band , whereby increased α - coher - ence has been linked to fluid complex higher - order functions , such as central executive control ( Sauseng et al . 2005 : also specific to the fronto - parietal netw"
ABSTRACT: To illuminate candidate neural working mech-anisms of Mindfulness-Based Cognitive Therapy (MBCT) in the treatment of recurrent depressive disorder, parallel to the potential interplays between modulations in electro-cortical dynamics and depressive symptom severity and self-compassionate experience. Linear and nonlinear α and γ EEG oscillatory dynamics were examined concomitant to an affective Go/NoGo paradigm, pre-to-post MBCT or natural wait-list, in 51 recurrent depressive patients. Spe-cific EEG variables investigated were; (1) induced event-related (de-) synchronisation (ERD/ERS), (2) evoked power, and (3) inter-/intra-hemispheric coherence. Sec-ondary clinical measures included depressive severity and experiences of self-compassion. MBCT significantly downregulated α and γ power, reflecting increased cortical excitability. Enhanced α-desynchronisation/ERD was observed for negative material opposed to attenuated α-ERD towards positively valenced stimuli, suggesting acti-vation of neural networks usually hypoactive in depression, related to positive emotion regulation. MBCT-related increase in left-intra-hemispheric α-coherence of the fron-to-parietal circuit aligned with these synchronisation dynamics. Ameliorated depressive severity and increased self-compassionate experience pre-to-post MBCT corre-lated with α-ERD change. The multi-dimensional neural mechanisms of MBCT pertain to task-specific linear and non-linear neural synchronisation and connectivity network dynamics. We propose MBCT-related modulations in dif-fering cortical oscillatory bands have discrete excitatory (enacting positive emotionality) and inhibitory (disengag-ing from negative material) effects, where mediation in the α and γ bands relates to the former. Keywords Major Depressive Disorder (MDD) · Mindfulness-Based Cognitive Therapy (MBCT) · ERD/ERS · Oscillatory EEG · α-Band coherence · γ-Band · EEG power IntroductionCognitive Neurodynamics 02/2015; 9(1):13-29. DOI:10.1007/s11571-014-9308-y · 1.77 Impact Factor
- "This finding extends previous reports of cognitive differences between late-onset and early-onset MDD patients (Herrmann et al. 2007). These pronounced deficits might be related to progressive abnormalities in cortico-striatal-pallidal-thalamic circuits that have been identified in MDD (Rogers et al. 1998 ; Marchand & Yurgelun-Todd, 2010 ; Bora et al. 2012 b) as well as vascular changes in white matter (Herrmann et al. 2008). Verbal memory problems might be related to a risk of future neurodegenerative disorders in some of these patients (Yeh et al. 2011 ; Vilalta-Franch et al. 2012). "
Dataset: MDD cog
[Show abstract] [Hide abstract]
- "Several papers demonstrated that striatal dopamine may also play an important role in the pathophysiology of depression by modulating emotional and motor symptoms (Byrum et al., 1999; Newberg et al., 2007; Rogers et al., 1998). Some researchers have suggested that psychomotor disturbance may be a cardinal marker of endogenous depression (Rogers et al., 1998). Mann and Kapur, (1995) reported dopaminergic drugs to be therapeutic for major depression, particularly where psychomotor disturbance was involved. "
ABSTRACT: Disturbances in noradrenergic and serotonergic transmissions have been postulated to form neurochemical background of depression. 1-Methyl-1,2,3,4-tetrahydroisoquinoline (1MeTIQ) is an endogenous substance which exhibits neuroprotective, antiaddictive and monoamine oxidase (MAO)-inhibiting properties. In the present study, we tested antidepressant-like effects of 1MeTIQ in comparison with the tricyclic antidepressant, imipramine in the forced swimming test in the rat. Additionally, in neurochemical studies, we estimated the rate of monoamine (dopamine, noradrenaline and serotonin) metabolism in the rat brain structures. The findings have shown that 1MeTIQ similarly to imipramine produced a dose-dependent antidepressant-like effect in the forced swimming test. The neurochemical data showed that 1MeTIQ produced a significant elevation of serotonin concentration in the brain structures with simultaneous reduction of its metabolite, 5-hydroxyindoleacetic acid (5-HIAA). Moreover, 1MeTIQ slightly increased noradrenaline level but induced a significant elevation of its metabolite, 3-metoxy-4-hydroxyphenylglycol (MHPG). Furthermore, 1MeTIQ affected also dopamine metabolism, and decreased the level of 3,4-dihydroxyphenylacetic acid (DOPAC) with a simultaneous significant increase in the concentration of 3-methoxytyramine (3-MT) in all investigated structures. Such mechanism of action leads to a decrease in the production of free radicals during MAO-dependent dopamine oxidation in the brain. In conclusion, we suggest that antidepressant-like activity of 1MeTIQ is based on the unique and complex mechanism of action in which the activation of monoaminergic systems and scavenging of free radicals plays a crucial role. 1MeTIQ as an endogenous compound may be beneficial from the clinical point of view as a new safer and more efficient antidepressant.European journal of pharmacology 12/2012; 700(1-3). DOI:10.1016/j.ejphar.2012.11.063 · 2.68 Impact Factor