Cognitive component of psychomotor retardation in unipolar and bipolar depression: Is verbal fluency a relevant marker? Impact of repetitive transcranial stimulation

Psychomotor retardation: What about the partial responders to magnetic transcranial stimulation in treatment resistant depression ?

OBJECTIVE

Psychomotor retardation is a core clinical component of Major Depressive Disorder responsible for disability and is known as a treatment response marker of biological treatments for depression. Our objective was to describe cognitive and motoric measures changes during a treatment by repetitive Transcranial Magnetic Stimulation (rTMS) within the THETAD-DEP trial for treatment-resistant depression (TRD), and compare those performances at the end of treatment and one month after between responders (>50% improvement on MADRS score), partial responders (25-50%) and non-reponders (no clinically relevant improvement). Our secondary aim was to investigate baseline psychomotor performances associated with non-response and response even partial.

METHODS

Fifty-four patients with treatment-resistant unipolar depression and treated by either high frequency 10 Hz rTMS or iTBS for 4 weeks (20 sessions) underwent assessment including French Retardation Rating Scale for Depression (ERD), Verbal Fluency test, and Trail Making Test A. before, just after treatment and one month later.

RESULTS

20 patients were responders (R, 21 partial responders (PR) and 13 non-responders (NR). rTMS treatment improved psychomotor performances in the R and PR groups unlike NR patients whose psychomotor performance was not enhanced by treatment. At baseline, participants, later identified as partial responders, showed significantly higher performances than non-responders.

CONCLUSION

Higher cognitivo-motor performances at baseline may be associated with clinical improvement after rTMS treatment. This work highlights the value of objective psychomotor testing for the identification of rTMS responders and partial responders, and thus may be useful for patient selection and protocol individualization such as treatment continuation for early partial responders.

Dynamics of Depressive and Psychomotor Symptoms During Electroconvulsive Therapy in Older Depressive Patients: A Case Series

OBJECTIVE

Electroconvulsive therapy (ECT) is an effective treatment for patients experiencing a major depressive episode, especially older ones. Identification of specific responses within early ECT sessions remains an issue of debate, however. Hence, this pilot study prospectively examined the outcome in terms of depressive signs, symptom by symptom, throughout a course of ECT, concentrating particularly on psychomotor retardation symptoms.

METHODS

Nine patients were clinically evaluated several times during the ECT course, before the first session and then weekly (over 3-6 weeks, according to their evolution), by completing the Montgomery-Åsberg Depression Rating Scale (MADRS), the Mini-Mental State Examination test, and the French Retardation Rating Scale for Depression for assessing the severity of psychomotor retardation.

RESULTS

Nonparametric Friedman tests showed significant positive changes in mood disorders during ECT in older depressive patients (mean, -27.3% of initial MADRS total score). Fast improvement in French Retardation Rating Scale for Depression score was observed at t1 (ie, after 3-4 ECT sessions), whereas a slightly delayed improvement in the MADRS scores was found at t2 (ie, after 5-6 ECT sessions). Moreover, the scores for items linked to the motor component of psychomotor retardation (eg, gait, postural control, fatigability) were the first to significantly decrease during the first 2 weeks of the ECT course compared with the cognitive component.

CONCLUSIONS

Interestingly, participants' concentration on daily functional activities, their interest and fatigability, and their reported state of sadness were the first to progress, representing possible precursor signs of positive patient outcomes after ECT.

Spontaneous beta power, motor-related beta power and cortical thickness in major depressive disorder with psychomotor disturbance

INTRODUCTION

The psychomotor disturbance is a common symptom in patients with major depressive disorder (MDD). The neurological mechanisms of psychomotor disturbance are intricate, involving alterations in the structure and function of motor-related regions. However, the relationship among changes in the spontaneous activity, motor-related activity, local cortical thickness, and psychomotor function remains unclear.

METHOD

A total of 140 patients with MDD and 68 healthy controls performed a simple right-hand visuomotor task during magnetoencephalography (MEG) scanning. All patients were divided into two groups according to the presence of psychomotor slowing. Spontaneous beta power, movement-related beta desynchronization (MRBD), absolute beta power during movement and cortical characteristics in the bilateral primary motor cortex were compared using general linear models with the group as a fixed effect and age as a covariate. Finally, the moderated mediation model was tested to examine the relationship between brain metrics with group differences and psychomotor performance.

RESULTS

The patients with psychomotor slowing showed higher spontaneous beta power, movement-related beta desynchronization and absolute beta power during movement than patients without psychomotor slowing. Compared with the other two groups, significant decreases were found in cortical thickness of the left primary motor cortex in patients with psychomotor slowing. Our moderated mediation model showed that the increased spontaneous beta power indirectly affected impaired psychomotor performance by abnormal MRBD, and the indirect effects were moderated by cortical thickness.

CONCLUSION

These results suggest that patients with MDD have aberrant cortical beta activity at rest and during movement, combined with abnormal cortical thickness, contributing to the psychomotor disturbance observed in this patient population.

[Comorbidity patterns and structure of depressive episodes in patients with bipolar disorder and major depressive disorder]

OBJECTIVE

To conduct an exploratory analysis of comorbidity patterns and the structure of depressive episodes among Russian patients with bipolar disorder (BD) and major depressive disorder (MDD).

MATERIAL AND METHODS

This multicenter cross-sectional study included 178 patients with mood disorders, of which 78.1% (n=139) were women. The diagnosis of BD was made in 68.0% (n=121) patients, of them 37.1% (n=66) were diagnosed with BD type I. All study participants underwent a structured Mini International Neuropsychiatric Interview to verify the clinical diagnosis and identify concomitant mental disorders, and also filled out an electronic case report form. Statistical analysis was performed in RStudio v. 1.4.1717 using the standard R package and the «psych» package.

RESULTS

According to the results of stepwise regression, comorbid diagnoses of panic disorder (OR=5.3; 95% CI 1.9-19.1) and eating disorders (OR=7.7; 95% CI 2.8-27.4) were more associated with BD. In addition, depressive episodes in BD were more associated with symptoms of hypersomnia (OR=2.5; 95% CI 1.2-5.3) and psychomotor retardation (OR=3.2; 95% CI 1.5-7.6). Symptoms such as increased appetite (47.1% (n=57) vs 26.3% (n=15); p=0.009), ideas of guilt (92.6% (n=112) vs 7.2% (n=44); p=0.006) and thoughts of self-harm or death (70.2% (n=85) vs 45.6% (n=25); p=0.003) were also nominally more common in depressive episodes within the BD compared to MDD.

CONCLUSIONS

Mood disorders such as BD and MDD have significant differences in the patterns of comorbidity and the structure of depressive episodes, which is important to consider when conducting differential diagnosis of these disorders. The results also indicate the need for a comprehensive diagnostic interview with patients with mood disorders to assess the presence of comorbid mental disorders during life and the structure of depressive episodes throughout the clinical course from the moment of onset.

Cognitive functioning as predictor and marker of response to repetitive transcranial magnetic stimulation in depressive disorders: A systematic review

OBJECTIVE

Cognitive performance in Major Depressive Disorder (MDD) is frequently impaired and related to functional outcomes. Repetitive Transcranial Magnetic Stimulation (rTMS) may exert its effects on MDD acting both on depressive symptoms and neurocognition. Furthermore, cognitive status could predict the therapeutic response of depressive symptoms to rTMS. However, cognitive performances as a predictor of rTMS response in MDD has not been thoroughly investigated. This review aims to evaluate the role of pre-treatment cognitive performance as a predictor of clinical response to rTMS, and the effects of rTMS on neurocognition in MDD.

METHOD

A systematic review of studies evaluating neurocognition in MDD as an outcome and/or predictor of response to rTMS was conducted using PubMed/Medline and Embase.

RESULTS

Fifty-eight articles were identified: 25 studies included neurocognition as a predictor of response to rTMS; 56 used cognitive evaluation as an outcome of rTMS. Baseline cognitive performance and cognitive improvements after rTMS predicted clinical response to rTMS. Moreover, rTMS improved cognition in MDD.

CONCLUSIONS

Cognitive assessment could predict improvement of depression in MDD patients undergoing rTMS and help selecting patients that could have beneficial effects from rTMS. A routine cognitive assessment might stratify MDD patients and track rTMS related cognitive improvement.

Anxiolytic Effect of Carvedilol in Chronic Unpredictable Stress Model

Anxiety disorders are the most prevalent psychiatric disorders being also a comorbid state of other diseases. We aimed to evaluate the anxiolytic-like effects of carvedilol (CVD), a drug used to treat high blood pressure and heart failure with potent antioxidant effects, in animals exposed to chronic unpredictable stress (CUS). To do this, female Swiss mice were exposed to different stressors for 21 days. Between days 15 and 21, the animals received oral CVD (5 or 10 mg/kg) or the antidepressant desvenlafaxine (DVS 10 mg/kg). On the 22^nd day, behavioral tests were conducted to evaluate locomotor activity (open field) and anxiety-like alterations (elevated plus-maze—EPM and hole board—HB tests). After behavioral determinations, the animals were euthanized, and the adrenal gland, blood and brain areas, prefrontal cortex (PFC), and hippocampus were removed for biochemical analysis. CUS reduced the crossings while increased rearing and grooming, an effect reversed by both doses of CVD and DVS. CUS decreased the number of entries and permanence time in the open arms of the EPM, while all treatments reversed this effect. CUS reduced the number of head dips in the HB, an effect reversed by CVD. The CUS reduced weight gain, while only CVD5 reversed this effect. A reduction in the cortical layer size of the adrenal gland was observed in stressed animals, which CVD reversed. Increased myeloperoxidase activity (MPO) and interferon-γ (IFN-γ), as well as reduction of interleukin-4 (IL-4) induced by CUS, were reversed by CVD. DVS and CVD increased IL-6 in both brain areas. In the hippocampus, DVS caused an increase in IFN-γ. Our data show that CVD presents an anxiolytic effect partially associated with immune-inflammatory mechanism regulation.

Involvement of oxidative pathways and BDNF in the antidepressant effect of carvedilol in a depression model induced by chronic unpredictable stress

RATIONALE

Depression is a severe psychiatric disorder with oxidative imbalance and neurotrophic deficits as underlying mechanisms.

OBJECTIVES

Based on the antioxidant effects of carvedilol (CARV), here, we aimed to evaluate CARV's effects against depression induced by the chronic unpredictable stress (CUS) model.

METHODS

Female Swiss mice were submitted to the CUS protocol for 21 days. Between days 15 and 22, the animals received CARV (5 or 10 mg/kg) or desvenlafaxine (DVS 10 mg/kg) orally. On the 22nd day, mice were subjected to behavioral tests to evaluate locomotion, depressive-like behavior (tail suspension test), motivation/self-care with the splash test (ST), social interaction, and working memory Y-maze test. The prefrontal cortex (PFC) and hippocampus were dissected to evaluate alterations of oxidative and brain-derived neurotrophic factor (BDNF).

RESULTS

The CUS model reduced locomotion and increased grooming latency, while it reduced the number of groomings in the ST. Both doses of CARV and DVS reverted these alterations. In addition, DVS and CARV reversed CUS model-induced working memory and social interaction deficits. The CUS model decreased hippocampal reduced glutathione (GSH), while DVS and CARV increased GSH in the PFC (CARV5) and hippocampus (CARV5 and 10). The CUS model increased nitrite and malondialdehyde (MDA) concentrations in both areas. All treatments reversed nitrite alterations, while CARV10 changed MDA levels in PFC and all treatments in the hippocampus. The CUS model reduced BDNF levels. CARV10 increased BDNF in the PFC, while both doses of CARV increased hippocampal levels of this neurotrophin.

CONCLUSIONS

CARV presents antidepressant-like effects comparable to those observed with DVS. In addition, it has an antioxidant effect and is capable of increasing BDNF brain concentrations. Further studies are needed to elucidate the mechanisms involved in the antidepressant effect of CARV.

Network reorganization during verbal fluency task in fronto-temporal epilepsy: A functional near-infrared spectroscopy study

This is the first study to use functional near-infrared spectroscopy (fNIRS) to investigate how the lateralization of the epileptogenic zone affects the reconfiguration of task-related network patterns. Eleven left fronto-temporal epilepsy (L-FTE) and 11 right fronto-temporal epilepsy (R-FTE), as well as 22 age- and gender-matched controls, were enrolled. Signals from 52-channel fNIRS were recorded while the subject was undertaking verbal fluency tasks (VFTs), which included categorical (CFT) and letter (LFT) fluency tasks. Three analytic methods were used to study the network topology: network-based analysis, hub identification, and proportional threshold to select the top 20% strongest connections for both graph theory parameters and clinical correlation. Performance of CFT is accomplished primarily using the ventral pathway, and bilateral ventral pathways are augmented in fronto-temporal epilepsy patients by strengthening the inter-hemispheric connections, especially for R-FTE. LFT mainly employed the dorsal pathway, and further prioritized the left dorsal pathway in strengthening intra-hemispheric connections in fronto-temporal epilepsy, especially L-FTE. The top 20% of the strongest connections only present differences in CFT network compared with the controls. R-FTE increased inter-hemispheric network density, while L-FTE decreased inter-hemispheric average characteristic path length. Accumulative seizure burden only affects L-FTE network. Better LFT performance and longer educational years seem to promote left fronto-temporal networks, and decreased the demand from RR intra-hemispheric connectivity in L-FTE. LFT scores in R-FTE are maintained by preserved RR intra-hemispheric networks. However, CFT scores and educational years seem to have no effect on the CFT network topology in both FTE.

Two Methods for Calculating Symptom Cluster Scores

BACKGROUND

Symptom clusters are conventionally distilled into a single score using composite scoring, which is based on the mathematical assumption that all symptoms are equivalently related to outcomes of interest; this may lead to a loss of important variation in the data.

OBJECTIVES

This article compares two ways of calculating a single score for a symptom cluster: a conventional, hypothesis-driven composite score versus a data-driven, reduced rank regression score that weights the symptoms based on their individual relationships with key outcomes.

METHODS

We conducted a secondary analysis of psychoneurological symptoms from a sample of 356 low-income mothers. Four of the psychoneurological symptoms (fatigue, cognitive dysfunction, sleep disturbance, and depressed mood) were measured with the Center for Epidemiological Studies Depression Scale; the fifth (pain) was measured using an item from the Medical Outcomes Study 12-item Short Form Health Survey (SF-12). Mothers' function was measured using the 12-item Short Form Health Survey. The composite score was calculated by summing standardized scores for each individual psychoneurological symptom. In contrast, reduced rank regression weighted the individual symptoms using their respective associations with mothers' function; the weighted individual symptom scores were summed into the reduced rank regression symptom score.

RESULTS

The composite score and reduced rank regression score were highly correlated at .93. The cluster of psychoneurological symptoms accounted for 53.7% of the variation in the mothers' function. Depressed mood and pain accounted for almost all the explained variation in mothers' function at 37.2% and 15.0%, respectively.

DISCUSSION

The composite score approach was simpler to calculate, and the high correlation with the reduced rank regression score indicates that the composite score reflected most of the variation explained by the reduced rank regression approach in this data set. However, the reduced rank regression analysis provided additional information by identifying pain and depressed mood as having the strongest association with a mother's function, which has implications for understanding which symptoms to target in future interventions. Future studies should also explore composite versus reduced rank regression approaches given that reduced rank regression may yield different insights in other data sets.

Cognitive changes after tDCS and escitalopram treatment in major depressive disorder: Results from the placebo-controlled ELECT-TDCS trial

BACKGROUND

Cognitive deficits in major depressive disorder (MDD) are associated with low quality of life and higher suicide risk. Antidepressant drugs have modest to null effects in improving such deficits. Therefore, we investigated the cognitive effects of transcranial direct current stimulation (tDCS), which is a promising antidepressant non-pharmacological intervention, in MDD.

METHODS

An exploratory analysis on cognitive performance was conducted in 243 depressed patients from the Escitalopram vs. Electric Current Therapy for Treating Depression Clinical Study (ELECT-TDCS), a sham-controlled study comparing the efficacy of tDCS vs. escitalopram. A neuropsychological battery was applied at baseline and endpoint (10 weeks of treatment) to create composite cognitive scores (processing speed, working memory, and verbal fluency). Linear mixed regression models were used to evaluate changes according to intervention groups, adjusted for confounding variables (age, years of schooling, gender, and benzodiazepine use) and depression improvement.

RESULTS

No cognitive deterioration was observed in any group. Patients receiving tDCS presented reduced practice gains compared to placebo in processing speed. In patients receiving escitalopram vs. placebo and in the subgroup of clinical responders (>50% depression improvement from baseline), those receiving tDCS vs. placebo presented increased performance in verbal fluency. No significant differences between tDCS and escitalopram groups were detected.

LIMITATIONS

Absence of healthy controls.

CONCLUSION

Prefrontal tDCS did not lead to cognitive deficits in depressed patients, although it reduced practice effects in processing speed. tDCS responders presented increased performance in verbal fluency. Further investigation of tDCS cognitive effects in depression is warranted.

Combined Measures of Psychomotor and Cognitive Alterations as a Potential Hallmark for Bipolar Depression

OBJECTIVE

The current study aimed to examine whether specific features of psychomotor retardation (PMR) and cognitive functioning established different profiles in unipolar (UD) and bipolar depression (BD).

METHODS

Two groups of age-matched patients with UD (n=54) and BD (n=20) completed the Montgomery-Asberg Depression Rating Scale (MADRS/60), the Montreal Cognitive Assessment (MoCA/30), and the Salpêtrière Retardation Rating Scale (SRRS/60). We analyzed the group effect and then performed intra-group analyses.

RESULTS

The BD patients have higher SRRS score, and lower MoCA score than UD despite no difference on the level of depression between UD and BD. Our results show that PMR can be predicted by the level of depression in UD and by the cognitive alteration and onset of disease in BD.

CONCLUSION

PMR is a relevant marker of depression. Our results highlight the importance of concomitant evaluation of psychomotor and cognitive functions in the distinction of UD and BD symptoms.

Clinical applications of transcranial magnetic stimulation in bipolar disorder

BACKGROUND

Many patients with bipolar disorder (BD) fail to experience benefit following traditional pharmacotherapy, necessitating alternative treatment options that will enable such patients to achieve remission. Transcranial magnetic stimulation (TMS) is a relatively new, noninvasive neuromodulation technique that involves the application of magnetic pulses on hyperactive or hypoactive cortical brain areas. We evaluated the existing literature on TMS as a treatment for BD across varied mood states.

METHODS

We searched PubMed up to October 2018 for original data articles published in English that evaluated outcomes in a bipolar sample across depressive, manic, mixed, and maintenance phases of BD.

RESULTS

Clinical trials of TMS for BD particularly suggest the potential of repetitive TMS for reducing depressive symptoms. Studies of TMS for mania have yielded more mixed findings. Few studies have evaluated TMS in other phases of the bipolar illness. TMS is generally associated with mild side effects though, in a few studies, it has been shown to contribute to a manic switch in previously depressed bipolar patients.

CONCLUSIONS

Transcranial magnetic stimulation is a promising approach for treating patients with BD who have failed to respond to pharmacological or psychosocial treatment. Future research should more clearly elucidate which TMS protocols may be most effective for a given bipolar patient.

Posture-Motor and Posture-Ideomotor Dual-Tasking: A Putative Marker of Psychomotor Retardation and Depressive Rumination in Patients With Major Depressive Disorder

Background: Recent studies have demonstrated that the assessment of postural performance may be a potentially reliable and objective marker of the psychomotor retardation (PMR) in the major depressive disorder (MDD). One of the important facets of MDD-related PMR is reflected in disrupted central mechanisms of psychomotor control, heavily influenced by compelling maladaptive depressive rumination. In view of this we designed a research paradigm that included sequential execution of simple single-posture task followed by more challenging divided attention posture tasks, involving concurring motor and ideomotor workloads. Another difficulty dimension assumed executing of all the tasks with eyes open (EO) (easy) and closed (EC) (difficult) conditions. We aimed at investigating the interplay between the severity of MDD, depressive rumination, and efficiency of postural performance.

Methods: Compared with 24 age- and body mass index-matched healthy controls (HCs), 26 patients with MDD sequentially executed three experimental tasks: (1) single-posture task of maintaining a quiet stance (ST), (2) actual posture-motor dual task (AMT); and (3) mental/imaginary posture-motor dual task (MMT). All the tasks were performed in the EO and the EC conditions. The primary dependent variable was the amount of kinetic energy (E) expended for the center of pressure deviations (CoPDs), whereas the absolute divided attention cost index showed energy cost to the dual-tasking vs. the single-posture task according to the formula: ΔE = (E_Dual-task - E_Single-task).

Results: The signs of PMR in the MDD group were objectively indexed by deficient posture control in the EC condition along with overall slowness of fine motor and ideomotor activity. Another important and probably more challenging feature of the findings was that the posture deficit manifested in the ST condition was substantially and significantly attenuated in the MMT and AMT performance dual-tasking activity. A multiple linear regression analysis evidenced further that the dual-tasking energy cost (i.e., ΔE) significantly predicted clinical scores of severity of MDD and depressive rumination.

Conclusion: The findings allow to suggest that execution of concurrent actual or imaginary fine motor task with closed visual input deallocates attentional resources from compelling maladaptive depressive rumination thereby attenuating severity of absolute dual-tasking energy costs for balance maintenance in patients with MDD.

Significance: Quantitative assessment of PMR through measures of the postural performance in dual-tasking may be useful to capture the negative impact of past depressive episodes, optimize the personalized treatment selection, and improve the understanding of the pathophysiological mechanisms underlying MDD.