The gated cascade diffusion model: An integrated theory of decision making, motor preparation, and motor execution.

This article introduces an integrated and biologically inspired theory of decision making, motor preparation, and motor execution. The theory is formalized as an extension of the diffusion model, in which diffusive accumulated evidence from the decision-making process is continuously conveyed to motor areas of the brain that prepare the response, where it is smoothed by a mechanism that approximates a Kalman-Bucy filter. The resulting motor preparation variable is gated prior to reaching agonist muscles until it exceeds a particular level of activation. We tested this gated cascade diffusion model by continuously probing the electrical activity of the response agonists through electromyography in four choice tasks that span a variety of domains in cognitive sciences, namely motion perception, numerical cognition, recognition memory, and lexical knowledge. The model provided a good quantitative account of behavioral and electromyographic data and systematically outperformed previous models. This work represents an advance in the integration of processes involved in simple decisions and sheds new light on the interplay between decision and motor systems. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

French Society for Biological Psychiatry and Neuropsychopharmacology (AFPBN) guidelines for the management of patients with partially responsive depression and treatment-resistant depression: Update 2024.

INTRODUCTION: The purpose of this update is to add newly approved nomenclatures and treatments as well as treatments yet to be approved in major depressive disorder, thus expanding the discussions on the integration of resistance factors into the clinical approach. METHODS: Unlike the first consensus guidelines based on the RAND/UCLA Appropriateness Method, the French Association for Biological Psychiatry and Neuropsychopharmacology (AFPBN) developed an update of these guidelines for the management of partially responsive depression (PRD) and treatment-resistant depression (TRD). The expert guidelines combine scientific evidence and expert clinicians' opinions to produce recommendations for PRD and TRD. RESULTS: The recommendations addressed three areas judged as essential for updating the previous 2019 AFPBN guidelines for the management of patients with TRD: (1) the identification of risk factors associated with TRD, (2) the therapeutic management of patients with PRD and TRD, and (3) the indications, the modalities of use and the monitoring of recent glutamate receptor modulating agents (esketamine and ketamine). CONCLUSION: These consensus-based guidelines make it possible to build bridges between the available empirical literature and clinical practice, with a highlight on the 'real world' of the clinical practice, supported by a pragmatic approach centred on the experience of specialised prescribers in TRD.

Acute effect of transcranial direct current stimulation (tDCS) on postural control of trained athletes: A randomized controlled trial.

Transcranial direct current stimulation (tDCS) is used to modulate brain function, and can modulate motor and postural control. While the acute effect of tDCS is well documented on patients, little is still known whether tDCS can alter the motor control of healthy trained participants. This study aimed to assess the acute effect of tDCS on postural control of parkour practitioners, known for their good balance abilities and their neuromuscular specificities that make them good candidates for tDCS intervention. Eighteen parkour practitioners were tested on three occasions in the laboratory for each stimulation condition (2 mA; 20 minutes)-primary motor cortex (M1), dorsolateral prefrontal cortex (dlPFC) and sham (placebo). Postural control was evaluated PRE and POST each stimulation by measuring Center of Pressure (CoP) displacements on a force platform during static conditions (bipedal and unipedal stance). Following M1 stimulation, significant decreases were observed in CoP area in unipedal (from 607.1 ± 297.9 mm2 to 451.1 ± 173.9 mm2, P = 0.003) and bipedal (from 157.5 ± 74.1 mm2 to 117.6 ± 59.8 mm2 P<0.001) stances. As well, the CoP total length was significantly reduced in bipedal (from 3416.8 ± 295.4 mm to 3280.6 ± 306.2 mm, P = 0.005) as well as in unipedal stance (from 4259.6 ± 398.4 mm to 3846.5 ± 468.9 mm, P<0.001), only after M1 stimulation. Relative pre-post changes observed after M1 stimulation were negatively correlated to experience in parkour only after unipedal stance (r = 0.715, P<0.001), meaning that the more participants were trained the less tDCS was effective. No significant changes were noticed after sham and dlPFC stimulation. These results suggested that the modulation of gait performance in athletes following an acute intervention of tDCS is specific to the targeted brain region, and that postures with reduced base of support (such as unipedal stance) were more sensitive to tDCS.

Indirect effect of impulsivity on suicide risk through self-esteem and depressive symptoms in a population with treatment-resistant depression: A FACE-DR study.

INTRODUCTION: Suicide is a major health issue. Its prevalence is particularly high in subjects presenting major depression disorder (MDD), making this a key suicide-related risk factor. Suicide attempts in severe forms of MDD were assumed to be linked to impulsivity and loss of control. Nevertheless, we failed to find data specifically investigating the link between impulsivity and suicide risk in treatment-resistant depression (TRD). This study seeks to review this relationship. METHOD: Patients were recruited for a prospective cohort. Suicide risk and impulsivity were assessed using the International Neuropsychiatric Interview and Barratt Impulsiveness Scale, Version 10, respectively, while the severity of depressive symptoms was assessed using the Montgomery-Asberg Depression Rating Scale, anxiety with the State-Trait Anxiety Inventory and childhood maltreatment using the Childhood Trauma Questionnaire. RESULTS: 220 TRD patients were enrolled in the study. The impulsivity score was correlated with self-esteem, marital status, professional status and anxiety. There was no direct link to suicide risk. However, impulsivity was associated with self-esteem (coefficient: -0.24; p value 0.043) and depressive symptom severity (coefficient: 0.; p value 0.045). The suicide risk was significantly correlated with depressive symptom severity (coefficient = 0.38, p < 0.001) and self-esteem (coefficient = -0.34, p = 0.01). Considering these correlations, we postulated that the effect of impulsivity on suicide risk could be mediated by self-esteem in terms of depressive symptom severity and we finally found a relevant mediation model within impulsivity having an indirect effect on suicide risk by impacting self-esteem and depressive symptoms with anxiety also playing a significant role as a covariable. CONCLUSION: We found that impulsivity could play an indirect role with the involvement of self-esteem and depressive symptoms and the contributing role of anxiety.

Adaptations of the balloon analog risk task for neuroimaging settings: a systematic review.

Introduction: The Balloon Analog Risk Task (BART), a computerized behavioral paradigm, is one of the most common tools used to assess the risk-taking propensity of an individual. Since its initial behavioral version, the BART has been adapted to neuroimaging technique to explore brain networks of risk-taking behavior. However, while there are a variety of paradigms adapted to neuroimaging to date, no consensus has been reached on the best paradigm with the appropriate parameters to study the brain during risk-taking assessed by the BART. In this review of the literature, we aimed to identify the most appropriate BART parameters to adapt the initial paradigm to neuroimaging and increase the reliability of this tool. Methods: A systematic review focused on the BART versions adapted to neuroimaging was performed in accordance with PRISMA guidelines. Results: A total of 105 articles with 6,879 subjects identified from the PubMed database met the inclusion criteria. The BART was adapted in four neuroimaging techniques, mostly in functional magnetic resonance imaging or electroencephalography settings. Discussion: First, to adapt the BART to neuroimaging, a delay was included between each trial, the total number of inflations was reduced between 12 and 30 pumps, and the number of trials was increased between 80 and 100 balloons, enabling us to respect the recording constraints of neuroimaging. Second, explicit feedback about the balloon burst limited the decisions under ambiguity associated with the first trials. Third, employing an outcome index that provides more informative measures than the standard average pump score, along with a model incorporating an exponential monotonic increase in explosion probability and a maximum explosion probability between 50 and 75%, can yield a reliable estimation of risk profile. Additionally, enhancing participant motivation can be achieved by increasing the reward in line with the risk level and implementing payment based on their performance in the BART. Although there is no universal adaptation of the BART to neuroimaging, and depending on the objectives of a study, an adjustment of parameters optimizes its evaluation and clinical utility in assessing risk-taking.

Evolution of Cognitive Impairments in Treatment-Resistant Depression: Results from the Longitudinal French Centers of Expertise for Treatment-Resistant Depression (FACE-DR) Cohort.

Previous studies set out profound cognitive impairments in subjects with treatment-resistant depression (TRD). However, little is known about the course of such alterations depending on levels of improvement in those patients followed longitudinally. The main objective of this study was to describe the course of cognitive impairments in responder versus non-responder TRD patients at one-year follow-up. The second aim was to evaluate the predictive aspect of cognitive impairments to treatment resistance in patients suffering from TRD. We included 131 patients from a longitudinal cohort (FACE-DR) of the French Network of Expert TRD Centers. They undertook comprehensive sociodemographic, clinical, global functioning, and neuropsychological testing (TMT, Baddeley task, verbal fluencies, WAIS-4 subtests, D2 and RLRI-16) at baseline (V0) and one-year follow-up (V1). Most patients (n = 83; 63.36%) did not respond (47 women, 49.47 ± 12.64 years old), while one-third of patients responded (n = 48, 30 women, 54.06 ± 12.03 years old). We compared the cognitive performances of participants to average theoretical performances in the general population. In addition, we compared the cognitive performances of patients between V1 and V0 and responder versus non-responder patients at V1. We observed cognitive impairments during the episode and after a therapeutic response. Overall, each of them tended to show an increase in their cognitive scores. Improvement was more prominent in responders at V1 compared to their non-responder counterparts. They experienced a more marked improvement in code, digit span, arithmetic, similarities, and D2 tasks. Patients suffering from TRD have significant cognitive impairments that persist but alleviate after therapeutic response. Cognitive remediation should be proposed after therapeutic response to improve efficiency and increase the daily functioning.

Long-term benzodiazepine prescription in treatment-resistant depression: A national FACE-TRD prospective study.

BACKGROUND: Benzodiazepine long-term use (BLTU) is a public health challenge. We lack data on the consequences of LBTU on the trajectory of treatment-resistant depression (TRD). OBJECTIVE: To determine the prevalence of BLTU in a nationwide non-selected population of patients with TRD, to determine the rate of patients succeeding at withdrawing benzodiazepines at one year and to determine if persistent BLTU is associated with poorer mental health outcomes. METHOD: The FACE-TRD cohort is a national cohort of TRD patients recruited in 13 resistant depression expert centers between 2014 and 2021 and followed-up at one year. A standardized one-day long comprehensive battery was carried out, including trained-clinician and patient-reported outcomes, and patients were reevaluated at one year. RESULTS: At baseline, 45.2% of the patients were classified in the BLTU group. In multivariate analysis, compared to patients without BLTU, patients with BLTU were more frequently classified in the "low physical activity" group (adjusted odds ratio (aOR) = 1.885, p = 0.036), and had higher primary healthcare consumption (B = 0.158, p = 0.031) independently of age, sex and antipsychotic consumption. We found no significant difference for personality traits, suicidal ideation, impulsivity, childhood trauma exposure, earlier age at first major depressive episode, anxiety and sleep disorders (all p > 0.05). Despite recommendations for withdrawal, <5% of BLTU patients withdraw benzodiazepines during the one-year follow-up. Persistent BLTU at one-year was associated with higher depression severity (B = 0.189, p = 0.029), higher clinical global severity (B = 0.210, p = 0.016), higher state-anxiety (B = 0.266, p = 0.003), impaired sleep quality (B = 0.249, p = 0.008), increased peripheral inflammation (B = 0.241, p = 0.027), lower functioning level (B = -0.240, p = 0.006), decreased processing speed (B = -0.195, p = 0.020) and verbal episodic memory (B = -0.178, p = 0.048), higher absenteeism and productivity loss (B = 0.595, p = 0.016) and lower subjective global health status (B = -0.198, p = 0.028). CONCLUSION: Benzodiazepines are over-prescribed in TRD (in almost a half of the patients). Despite recommendations for withdrawal and psychiatric follow-up, <5% of patients successfully stopped taking benzodiazepines at one-year. Maintaining BLTU may contribute to the worsening of clinical and cognitive symptoms and of daily functioning in TRD patients. Progressive and planed withdrawal of benzodiazepines seems therefore strongly recommended in TRD patients with BLTU. Pharmacological and non-pharmacological alternatives should be promoted when possible.

Time-course of the tDCS antidepressant effect: An individual participant data meta-analysis.

INTRODUCTION: Prefrontal transcranial direct current stimulation (tDCS) shows promise as an effective treatment for depression. However, factors influencing treatment and the time-course of symptom improvements remain to be elucidated. METHODS: Individual participant data was collected from ten randomised controlled trials of tDCS in depression. Depressive symptom scores were converted to a common scale, and a linear mixed effects individual growth curve model was fit to the data using k-fold cross-validation to prevent overfitting. RESULTS: Data from 576 participants were analysed (tDCS: n = 311; sham: n = 265), of which 468 were unipolar and 108 had bipolar disorder. tDCS effect sizes reached a peak at approximately 6 weeks, and continued to diverge from sham up to 10 weeks. Significant predictors associated with worse response included higher baseline depression severity, treatment resistance, and those associated with better response included bipolar disorder and anxiety disorder. CONCLUSIONS: Our findings suggest that longer treatment courses, lasting at least 6 weeks in duration, may be indicated. Further, our results show that tDCS is effective for depressive symptoms in bipolar disorder. Compared to unipolar depression, participants with bipolar disorder may require additional maintenance sessions to prevent rapid relapse.

Diurnal symptoms of sleepiness and dysfunction predict future suicidal ideation in a French cohort of outpatients (FACE-DR) with treatment resistant depression: A 1-year prospective study about sleep markers.

BACKGROUND: Patients suffering from treatment-resistant depression (TRD) are at risk of suicide. Sleep and circadian rhythm alterations are widely recognized as core symptoms of major depressive disorder and are associated with suicidal ideation. Thus, sleep and circadian rhythm alterations may be targeted to prevent suicide. METHODS: Patients were recruited from a prospective cohort of the French network of TRD expert centers. Mood, sleep and circadian rhythms were assessed at baseline; suicidal risk was assessed both at baseline and during a one-year follow-up with standardized subjective questionnaires. RESULTS: Excessive daytime sleepiness (adjusted odds ratio aOR = 1.7(1-3.3), p = 0.04) and daytime dysfunction (aOR = 1.81(1.16-2.81), p = 0.0085) increased the risk of suicidal thoughts over the one-year follow-up period in patients with TRD after adjustment on age, gender, depression, trauma, anxiety, impulsivity, current daily tobacco smoking and body mass index. Hypnotics intake is associated with a reduced risk of suicidal ideation at one-year follow-up after the same adjustments (OR = 0.73(0.56-0.95), p = 0.019). Other associations between sleep quality or circadian rhythms and suicidal ideations at either baseline or one year did not remain significant in multivariate analyses after the same adjustments. LIMITATIONS: Sleep assessments were based on self-reported questionnaires rather than objective measures. CONCLUSIONS: Daytime sleepiness and dysfunction are predictors of suicidal ideations, whereas hypnotics intake is associated with a reduced risk of suicidal ideations. Diurnal symptoms of sleep disturbances are therefore red flags to target for preventing suicide in depressed patients, and hypnotics seem efficient in preventing suicide for patients with TRD.

Clinical features and outcomes of COVID-19 patients hospitalized for psychiatric disorders: a French multi-centered prospective observational study.

BACKGROUND: Patients with psychiatric disorders are exposed to high risk of COVID-19 and increased mortality. In this study, we set out to assess the clinical features and outcomes of patients with current psychiatric disorders exposed to COVID-19. METHODS: This multi-center prospective study was conducted in 22 psychiatric wards dedicated to COVID-19 inpatients between 28 February and 30 May 2020. The main outcomes were the number of patients transferred to somatic care units, the number of deaths, and the number of patients developing a confusional state. The risk factors of confusional state and transfer to somatic care units were assessed by a multivariate logistic model. The risk of death was analyzed by a univariate analysis. RESULTS: In total, 350 patients were included in the study. Overall, 24 (7%) were transferred to medicine units, 7 (2%) died, and 51 (15%) patients presented a confusional state. Severe respiratory symptoms predicted the transfer to a medicine unit [odds ratio (OR) 17.1; confidence interval (CI) 4.9-59.3]. Older age, an organic mental disorder, a confusional state, and severe respiratory symptoms predicted mortality in univariate analysis. Age >55 (OR 4.9; CI 2.1-11.4), an affective disorder (OR 4.1; CI 1.6-10.9), and severe respiratory symptoms (OR 4.6; CI 2.2-9.7) predicted a higher risk, whereas smoking (OR 0.3; CI 0.1-0.9) predicted a lower risk of a confusional state. CONCLUSION: COVID-19 patients with severe psychiatric disorders have multiple somatic comorbidities and have a risk of developing a confusional state. These data underline the need for extreme caution given the risks of COVID-19 in patients hospitalized for psychiatric disorders.

Do Individuals with Internet Gaming Disorder Share Personality Traits with Substance-Dependent Individuals?

(1) Background: Internet gaming disorder (IGD) shares many similarities with substance use disorder (SUD), contributing to its recognition as an addictive disorder. Nevertheless, no study has compared IGD to other addictive disorders in terms of personality traits established as highly co-occurring with SUDs. (2) Methods: We recruited a sample of gamers (massively multiplayer online role-playing games) (MMORPGs) via online in-game forums. We compared 83 individuals with IGD (MMORPG-IGD group) to 47 former heroin addicts under methadone maintenance treatment (MMT; MMT group) with regard to alexithymia, impulsivity, sensation seeking and aggressiveness assessed through self-administered scales, being TAS-20, BIS-10, Z-SSS and BDHI, respectively. (3) Results: Our results draw a relatively similar personality profile between groups but indicate that the subject traits are generally more pronounced in the MMT cohort. The overall lesser intensity of these traits in the MMORPG-IGD group might reflect the greater variability in the severity of the IGD. (4) Conclusions: IGD shares personality traits with MMT, and intensity may be influenced by the severity of the addiction or by certain direct environmental factors, and might also influence the propensity towards one behavior rather than another.

Cognitive functions in late-life depression.

Cognitive disorders are frequently found during late-life depression (LLD). Many cognitive functions may be concerned and can be explained by frontostriatal brain circuits and hippocampus dysfunctions partly through abnormalities related to cerebrovascular diseases. It seems important to distinguish between early and late onset depression, the cognitive characterisation and aetiopathogenesis of which differ in some respects. Cognitive impairment may represent markers of depression, but it is still unclear whether potential biomarkers of disease should be considered as markers of condition, trait or risk factors. These disorders may precede depression and persist despite symptomatic remission. Moreover, the interest of specifying these disorders is multiple because they can have pejorative consequences, such as by modifying emotional content, encouraging suicidal acts, limiting the effectiveness of psychotherapy, being a risk factor for a poor response to antidepressants, or being a potential risk factor for progression to a minor or major neurocognitive disorder, especially Alzheimer disease.

Recommendations of the treatment-resistant depression expert center network for promoting tobacco smoking cessation based on the results from the real-world FACE-TRD national cohort.

BACKGROUND: Tobacco smoking has been associated with suicide, impulsivity and depression in non-clinical populations with differences across sexes. OBJECTIVE: To determine the role of tobacco smoking in Treatment-Resistant Depression (TRD) according to sex in a precision-medicine approach. METHOD: The FACE-TRD cohort is a national cohort of TRD patients recruited in 13 resistant depression expert centers between 2014 and 2021 and followed-up at 6 months. A standardized one-day long comprehensive battery was carried out, including trained-clinician and patient-reported outcomes, and patients were reevaluated at 6 months on their smoking and psychiatric hospitalization outcomes. RESULTS: 355 TRD participants were included (222 women). The smoking rate was much higher in TRD women compared to the French general population (34% vs 24%) while it was comparable for men (approximately 29%). In multivariate analyses, compared to non-smoking women, female smokers had significantly increased number of lifetime psychiatric hospitalizations (standardized beta B = 0.232, p = 0.014) and electro-convulsive therapy (adjusted odds ratio (aOR) = 2.748, p = 0.005), increased suicidal ideations (aOR = 4.047, p = 0.031), history of suicide attempt (aOR = 1.994, p = 0.033), and increased impulsivity (B = 0.210, p = 0.006) and were more frequently treated by benzodiazepines (aOR = 1.848, p = 0.035) and third- or fourth-line TRD treatments (antipsychotics aOR = 2.270, p = 0.006, mood stabilizers aOR = 2.067 p = 0.044). Tobacco smoking at baseline was predictive of psychiatric hospitalization within 6 months in persistent smoking women (aOR = 2.636, p = 0.031). These results were not replicated in men, for whom tobacco smoking was only associated with increased clinician-rated and self-reported depressive symptoms (respectively B = 0.207, p = 0.022 and B = 0.184, p = 0.048). The smoking cessation rate at 6 months was higher in women than in men (12% vs. 7%). No patient was administered nicotine substitute or varenicline at the two timepoints. INTERPRETATION: Combining these results and those of the literature, we recommend that active tobacco cessation should be promoted in TRD to improve depression, suicide and impulsivity especially in women. Female smokers appear as a specific population with heavier mental health outcomes that should be specifically addressed.

Saccadic Eye Movements in Elderly Depressed Patients With Suicidal Behaviors: An Exploratory Eye-Tracking Study.

Suicidal behaviors (SBs) are often associated with impaired performance on neuropsychological executive functioning (EF) measures that encourage the development of more specific and reliable tools. Recent evidence could suggest that saccadic movement using eye tracking can provide reliable information on EF in depressive elderly. The aim of this study was to describe oculomotor performances in elderly depressed patients with SB. To achieve this aim, we compared saccadic eye movement (SEM) performances in elderly depressed patients (N = 24) with SB and with no SB in prosaccade (PS) and antisaccade (AS) tasks under the gap, step, and overlap conditions. All participants also underwent a complete neuropsychological battery. Performances were impaired in patients with SB who exhibited less corrected AS errors and longer time to correct them than patients with no SB. Moreover, both groups had a similar performance for PS latencies and correct AS. These preliminary results suggested higher cognitive inflexibility in suicidal patients compared to non-suicidal. This inflexibility may explain the difficulty of the depressed elderly in generating solutions to the resurgence of suicidal ideation (SI) to respond adequately to stressful environments. The assessment of eye movement parameters in depressed elderly patients may be a first step in identifying high-risk patients for suicide.

Occurrence of Side Effects in Treatment-Resistant Depression: Role of Clinical, Socio-Demographic and Environmental Characteristics.

Introduction: Treatment-resistant depression (TRD) is a disabling psychiatric condition characterized by the failure of two antidepressants (ADs). Since the occurrence of side effects (SEs) appears to be one of the main determinants of early discontinuation of pharmacological treatments contributing to a pseudo-resistance, the purpose of this study was to determine the parameters associated with the occurrence of SEs under ADs in a cohort of patients with TRD. Methods: An observational, cross-sectional, multicentre study was carried out using data from the French network of Expert Centers for TRD. For the 108 patients enrolled in the study, the statistical analyses focused on the overall occurrence and on the profile of the SEs (9 categories, 32 items). Results: SEs were influenced by age and sex and were positively associated with the intensity of anxious, depressive and suicidal symptoms, a history of childhood trauma (sexual abuse, emotional abuse and neglect), and negatively associated with self-esteem, and assessment of overall functioning. Conclusion: Using variables accessible in common practice, these results fall within the dynamic of a more tailored approach to medicine that could allow, through integrated pharmacological management, the continuation of antidepressant treatments, and therefore limit the risk of therapeutic failure.

Characteristics of Bipolar Patients with Cognitive Impairment of Suspected Neurodegenerative Origin: A Multicenter Cohort.

Bipolar disorder is associated with an increased risk of dementia with aging. Little is known regarding this association, limiting appropriate diagnosis and management. We aimed to describe the characteristics of bipolar patients with late cognitive impairment for whom the hypothesis of an underlying neurodegenerative disease had been raised. We performed a retrospective multicenter study, recruiting bipolar patients over 50 years old from five French tertiary memory centers who had undergone cerebrospinal fluid (CSF) biomarker assessment for Alzheimer's disease (AD). Clinical, neuropsychological, and paraclinical characteristics were analyzed and 78 patients were included. The mean age at the onset of cognitive impairment was 62.4 years (±9.2). The mean MMSE score was 22.8 (±4.5), the mean FAB was 11.7 (±3.9), and the mean FCRST was 15.8 (±7.4)/36.8 (±9.7) (free/total recall). A total of 48.6% of the patients displayed cognitive fluctuations, and 38.2% showed cognitive improvement during follow-ups; and 56.3% of the patients showed Parkinsonism, of which 12.7% had never received antipsychotics. Among patients who underwent DAT-scans, 35.3% displayed dopaminergic denervation; 10.3% of patients had CSF AD biological signature ("A+ T+" profile), while 56.4% had other abnormal CSF profiles. Thus, clinical presentation was dominated by executive dysfunction, episodic memory impairment, fluctuating cognition, and a high frequency of Parkinsonism. Specifically, high frequency of delusional episodes suggests limited tolerance of psychotropic drugs. Most patients had abnormal CSF biomarker profiles, but only a minority displayed AD's specific biomarker signature. Therefore, while our results unveil shared common neurocognitive features in bipolar patients with cognitive impairment of suspected neurodegenerative origin they suggest a participation of various underlying pathologies rather than a common degenerative mechanism in the pathophysiology of this condition.

Cognitive Impairment in Late-Life Depression: A Comparative Study of Healthy Older People, Late-Life Depression, and Mild Alzheimer's Disease Using Multivariate Base Rates of Low Scores.

Late-Life Depression (LLD) is often associated with cognitive impairment. However, distinction between cognitive impairment due to LLD and those due to normal aging or mild Alzheimer's Disease (AD) remain difficult. The aim of this study was to present and compare the multivariate base rates of low scores in LLD, mild AD, and healthy control groups on a battery of neuropsychological tests. Participants (ages 60-89) were 352 older healthy adults, 390 patients with LLD, and 234 patients with mild AD (i.e., MMSE ≥ 20). Multivariate base rates of low scores (i.e., ≤ 5th percentile) were calculated for each participant group within different cognitive domains (verbal episodic memory, executive skills, mental processing speed, constructional praxis, and language/semantic memory). Obtaining at least one low score was relatively common in healthy older people controls (from 9.4 to 17.6%), and may thus result in a large number of false positives. By contrast, having at least two low scores was unusual (from 0.3 to 4.6%) and seems to be a more reliable criterion for identifying cognitive impairment in LLD. Having at least three low memory scores was poorly associated with LLD (5.9%) compared to mild AD (76.1%) and may provide a useful way to differentiate between these two conditions [ χ ( 1 ) 2 = 329.8, p < 0.001; Odds Ratio = 50.7, 95% CI = 38.2-77.5]. The multivariate base rate information about low scores in healthy older people and mild AD may help clinicians to identify cognitive impairments in LLD patients, improve the clinical decision-making, and target those who require regular cognitive and clinical follow-up.

Repetitive Transcranial Magnetic Stimulation as an Add-On Treatment for Cognitive Impairment in Alzheimer's Disease and Its Impact on Self-Rated Quality of Life and Caregiver's Burden.

Alzheimer's disease (AD) is associated with progressive memory loss and decline in executive functions, as well as neuropsychiatric symptoms. Patients usually consider quality of life (QoL) and mood as more important for their health status than disease-specific physical and mental symptoms. In this open-label uncontrolled trial, 12 subjects diagnosed with AD underwent 10 sessions of repetitive transcranial magnetic stimulation (rTMS) over the left dorsolateral prefrontal cortex (10 Hz, 20 min, 2000 pulses/day, 110% MT). Outcomes were measured before and 30 days after treatment. Our primary objective was to test the efficacy of rTMS as an add-on treatment for AD on the global cognitive function, assessed through the Mini-Mental State Examination (MMSE) and the Mattis Dementia Rating Scale (MDRS). As secondary objectives, the detailed effect on cognitive functions, depression and anxiety symptoms, QoL, and functionality in daily life activities were evaluated, as well as correlations between QoL and cognition, depression and anxiety scores. The treatment significantly enhanced semantic memory and reduced anxiety. Improvement of these features in AD could become an important target for treatment strategies. Although limited by its design, this trial may contribute with another perspective on the analysis and the impact of rTMS on AD.

Towards a Functional Neuromarker of Impulsivity: Feedback-Related Brain Potential during Risky Decision-Making Associated with Self-Reported Impulsivity in a Non-Clinical Sample.

Risk-taking is part of the multidimensional nature of impulsivity, consisting of an active engagement in behaviors or choices with potentially undesirable results, with probability as the cost for an expected reward. In order to understand the neurophysiological activity during risky behavior and its relationship with other dimensions of impulsivity, we have acquired event-related-potential (ERP) data and self-reported impulsivity scores from 17 non-clinical volunteers. They underwent high-resolution electroencephalography (HR-EEG) combined with an adapted version of the Balloon Analogue Risk Task (BART), and completed the Barratt Impulsiveness Scale (BIS-10) and the Urgency, Premeditation, Perseverance, Sensation Seeking, Impulsive Behavior Scale (UPPS). The ERP components were sensitive to valence (FRN, P300) and risk/reward magnitude (SPN, RewP). Our main finding evidenced a positive correlation between the amplitude of the P300 component following positive feedback and both the global UPPS score and the (lack of) perseverance UPPS subscale, significant for several adjacent electrodes. This finding might suggest an adaptive form of impulsive behavior, which could be associated to the reduction on the difference of the P300 amplitude following negative and positive feedback. However, further investigation with both larger clinical and non-clinical samples is required.

[Cognitive functions in late life depression]. / Troubles cognitifs au cours de la dépression du sujet âgé.

Cognitive disorders are frequently found during late-life depression. Many cognitive functions may be concerned and can be explained by fronto-striatal brain circuits and hippocampus dysfunctions partly through abnormalities related to cerebrovascular diseases. It seems important to distinguish between early and late onset depression whose cognitive characterisation and etiopathogenia differ in some aspects. Cognitive impairment may represent markers of depression but it is still unclear whether one should consider potential biomarkers of disease state or trait or risk factor. These disorders may precede depression and persist despite symptomatic remission. Moreover, the interest of specifying these disorders is multiple because they can have pejorative consequences such as the modification of emotional content, promote suicidal act, limit the effectiveness of psychotherapy, be a risk factor for poor response to antidepressants. or be a potential risk factor for progression to a minor or major neurocognitive disorder, especially Alzheimer's disease.