[Early intervention in bipolar affective disorders: Why, when and how]. / Intervenir précocement dans les stades débutants du trouble bipolaire : pourquoi, quand et comment.

OBJECTIVES: Bipolar disorder (BD) is a chronic and severe psychiatric disease. There are often significant delays prior to diagnosis, and only 30 to 40 % of patients will experience complete remission. Since BD occurs most often at a young age, the disorder can seriously obstruct future socio-professional development and integration. Vulnerability-stress model of BD is considered to be the result of an interaction between vulnerability genes and environmental risk factors, which leads to the onset of the disorder most often in late adolescence or early adulthood. The clinical "staging" model of BD situates the subject in a clinical continuum of varying degrees of severity (at-risk status, first episode, full-blown BD). Given the demonstrated effectiveness of early intervention in the early stages of psychotic disorder, we posit that early intervention for early stages of BD (i.e. at-risk status and first episode mania or hypomania) would reduce the duration of untreated illness and optimize the chances of therapeutic response and recovery. METHODS: We conducted a narrative review of the literature to gather updated data on: (1) features of early stages: risk factors, at-risk symptoms, clinical specificities of the first manic episode; (2) early screening: targeted populations and psychometric tools; (3) early treatment: settings and therapeutic approaches for the early stages of BD. RESULTS: (1) Features of early stages: among genetic risk factors, we highlighted the diagnosis of BD in relatives and affective temperament including as cyclothymic, depressive, anxious and dysphoric. Regarding prenatal environmental risk, we identified peripartum factors such as maternal stress, smoking and viral infections, prematurity and cesarean delivery. Later in the neurodevelopmental course, stressful events and child psychiatric disorders are recognized as increasing the risk of developing BD in adolescence. At-risk symptoms could be classified as "distal" with early but aspecific expressions including anxiety, depression, sleep disturbance, decreased cognitive performance, and more specific "proximal" symptoms which correspond to subsyndromic hypomanic symptoms that increase in intensity as the first episode of BD approaches. Specific clinical expressions have been described to assess the risk of BD in individuals with depression. Irritability, mixed and psychotic features are often observed in the first manic episode. (2) Early screening: some individuals with higher risk need special attention for screening, such as children of people with BD. Indeed, it is shown that children with at least one parent with BD have around 50 % risk of developing BD during adolescence or early adulthood. Groups of individuals presenting other risk factors, experiencing an early stage of psychosis or depressive disorders should also be considered as targeted populations for BD screening. Three questionnaires have been validated to screen for the presence of at-risk symptoms of BD: the Hypomanic Personality Scale, the Child Behavior Checklist-Paediatric Bipolar Disorder, and the General Behavior Inventory. In parallel, ultra-high risk criteria for bipolar affective disorder ("bipolar at-risk") distinguishing three categories of at-risk states for BD have been developed. (3) Early treatment: clinical overlap between first psychotic and manic episode and the various trajectories of the at-risk status have led early intervention services (EIS) for psychosis to reach out for people with an early stage of BD. EIS offers complete biopsychosocial evaluations involving a psychiatric examination, semi-structured interviews, neuropsychological assessments and complementary biological and neuroimaging investigations. Key components of EIS are a youth-friendly approach, specialized and intensive care and client-centered case management model. Pharmaceutical treatments for at-risk individuals are essentially symptomatic, while guidelines recommend the use of a non-antipsychotic mood stabilizer as first-line monotherapy for the first manic or hypomanic episode. Non-pharmacological approaches including psychoeducation, psychotherapy and rehabilitation have proven efficacy and should be considered for both at-risk and first episode of BD. CONCLUSIONS: EIS for psychosis might consider developing and implementing screening and treatment approaches for individuals experiencing an early stage of BD. Several opportunities for progress on early intervention in the early stages of BD can be drawn. Training first-line practitioners to identify at-risk subjects would be relevant to optimize screening of this population. Biomarkers including functional and structural imaging measures of specific cortical regions and inflammation proteins including IL-6 rates constitute promising leads for predicting the risk of transition to full-blown BD. From a therapeutic perspective, the use of neuroprotective agents such as folic acid has shown particularly encouraging results in delaying the emergence of BD. Large-scale studies and long-term follow-up are still needed to achieve consensus in the use of screening and treatment tools. The development of specific recommendations for the early stages of BD is warranted.

Evolution and characteristics of the use of valproate in women of childbearing age with bipolar disorder: Results from the FACE-BD cohort.

BACKGROUND: Valproate is associated with teratogenic and neurodevelopmental effects. Several agencies have restricted the conditions of its prescription in bipolar disorders (BD). We aimed to assess the evolution of valproate prescription and the clinical profile of BD women of childbearing age receiving valproate. METHODS: Based on a large national cohort, we included all BD women 16-50 years old. Sociodemographic, clinical and pharmacological data were recorded. Logistic regression analyses were used to describe variables associated with valproate prescription. RESULTS: Of the 1018 included women 16-50 years old, 26.9% were treated with valproate with a mean daily dosage of 968 mg. The prevalence of BD women using valproate was 32.6% before May 2015 and 17.3% after May 2015 (p<0.001), the date of French regulatory publication of restriction of valproate prescription. The multivariate analysis revealed that the inclusion period after May 2015 (OR=0.54, CI 95% 0.37-0.78, p=0.001), the age lower than 40 years (OR=0.65, CI 95% 0.43-0.98, p=0.040) and the number of lifetime mood episodes (OR=0.98, CI 95% 0.95-0.99, p=0.040) were the variables negatively associated with the use of valproate. LIMITATIONS: Study could be underpowered to determine a clinical profile associated with valproate prescription. CONCLUSIONS: The regulatory change in BD women of childbearing age had a significant impact on valproate prescription, even if the prescription rate remains high. Important efforts are needed to help clinicians and patients to improve quality of care in BD women of childbearing age.

Minimum clinically important differences for the Functioning Assessment Short Test and a battery of neuropsychological tests in bipolar disorders: results from the FACE-BD cohort.

AIMS: Establishing the minimum clinically important difference (MCID) in functioning and cognition is essential to the interpretation of the research and clinical work conducted in bipolar disorders (BD). The present study aimed to estimate the MCID for the Functioning Assessment Short Test (FAST) and a battery of neuropsychological tests in BD. METHODS: Anchor-based and distributive methods were used to estimate the MCID for the FAST and cognition using data from a large, multicentre, observational cohort of individuals with BD. The FAST and cognition were linked with the Clinical Global Impressions Scale-Severity (CGI-S) and Global Assessment of Functioning (GAF) using an equipercentile method. The magnitude of the standard error measurement (s.e.m.) provided another estimate of the MCID. RESULTS: In total, 570 participants were followed for 2 years. Cross-sectional CGI-S and GAF scores were linked to a threshold ⩽7 on the FAST for functional remission. The MCID for the FAST equalled 8- or 9-points change from baseline using the CGI-S and GAF. One s.e.m. on the FAST corresponded to 7.6-points change from baseline. Cognitive variables insufficiently correlated with anchor variables (all ρ <0.3). One s.e.m. for cognitive variables corresponded to a range of 0.45 to 0.93-s.d. change from baseline. CONCLUSIONS: These findings support the value of the estimated MCID for the FAST and cognition and may be a useful tool to evaluate cognitive and functional remediation effects and improve patient functional outcomes in BD. The CGI-S and GAF were inappropriate anchors for cognition. Further studies may use performance-based measures of functioning instead.

Adherence to treatment guidelines in clinical practice for using electroconvulsive therapy in major depressive episode.

BACKGROUND: ECT is the most effective treatment of major depressive episode (MDE) but remains a neglected treatment. The French Society for Biological Psychiatry and Neuropsychopharmacology aimed to determine whether prescribing practice of ECT followed guidelines recommendations. METHODS: This multicenter, retrospective study included adult patients with major depressive disorder (MDD) or bipolar disorder (BD), who have been treated with ECT for MDE. Duration of MDE and number of lines of treatment received before ECT were collected. The reasons for using ECT, specifically first-line indications (suicidality, urgency, presence of catatonic and psychotic features, previous ECT response, patient preference) were recorded. Statistical comparisons between groups used standard statistical tests. RESULTS: Seven hundred and forty-five individuals were included. The mean duration of MDE before ECT was 10.1 months and the mean number of lines of treatment before ECT was 3.4. It was significantly longer for MDD single episode than recurrent MDD and BD. The presence of first-line indications for using ECT was significantly associated to shorter duration of MDE (9.1 vs 13.1 months, p<0.001) and lower number of lines of treatment before ECT (3.3 vs 4.1, p<0.001). LIMITATIONS: This is a retrospective study and not all facilities practicing ECT participated that could limit the extrapolation of the results. CONCLUSION: Compared to guidelines, ECT was not used as first-line strategy in clinical practice. The presence of first-line indications seemed to reduce the delay before ECT initiation. The improvements of knowledge and access of ECT are needed to decrease the gap between guidelines and clinical practice.

Clinical guidelines for the management of treatment-resistant depression: French recommendations from experts, the French Association for Biological Psychiatry and Neuropsychopharmacology and the fondation FondaMental.

BACKGROUND: Clear guidance for successive antidepressant pharmacological treatments for non-responders in major depression is not well established. METHOD: Based on the RAND/UCLA Appropriateness Method, the French Association for Biological Psychiatry and Neuropsychopharmacology and the fondation FondaMental developed expert consensus guidelines for the management of treatment-resistant depression. The expert guidelines combine scientific evidence and expert clinicians' opinions to produce recommendations for treatment-resistant depression. A written survey comprising 118 questions related to highly-detailed clinical presentations was completed on a risk-benefit scale ranging from 0 to 9 by 36 psychiatrist experts in the field of major depression and its treatments. Key-recommendations are provided by the scientific committee after data analysis and interpretation of the results of the survey. RESULTS: The scope of these guidelines encompasses the assessment of pharmacological resistance and situations at risk of resistance, as well as the pharmacological and psychological strategies in major depression. CONCLUSION: The expert consensus guidelines will contribute to facilitate treatment decisions for clinicians involved in the daily assessment and management of treatment-resistant depression across a number of common and complex clinical situations.

Clinical guidelines for the management of depression with specific comorbid psychiatric conditions French recommendations from experts (the French Association for Biological Psychiatry and Neuropsychopharmacology and the fondation FondaMental).

BACKGROUND: Recommendations for pharmacological treatments of major depression with specific comorbid psychiatric conditions are lacking. METHOD: The French Association for Biological Psychiatry and Neuropsychopharmacology and the fondation FondaMental developed expert consensus guidelines for the management of depression based on the RAND/UCLA Appropriatneness Method. Recommendations for lines of treatment are provided by the scientific committee after data analysis and interpretation of the results of a survey of 36 psychiatrist experts in the field of major depression and its treatments. RESULTS: The expert guidelines combine scientific evidence and expert clinician's opinion to produce recommendations for major depression with comorbid anxiety disorders, personality disorders or substance use disorders and in geriatric depression. CONCLUSION: These guidelines provide direction addressing common clinical dilemmas that arise in the pharmacologic treatment of major depression with comorbid psychiatric conditions.

Emotional hyper-reactivity and cardiometabolic risk in remitted bipolar patients: a machine learning approach.

OBJECTIVE: Remitted bipolar disorder (BD) patients frequently present with chronic mood instability and emotional hyper-reactivity, associated with poor psychosocial functioning and low-grade inflammation. We investigated emotional hyper-reactivity as a dimension for characterization of remitted BD patients, and clinical and biological factors for identifying those with and without emotional hyper-reactivity. METHOD: A total of 635 adult remitted BD patients, evaluated in the French Network of Bipolar Expert Centers from 2010-2015, were assessed for emotional reactivity using the Multidimensional Assessment of Thymic States. Machine learning algorithms were used on clinical and biological variables to enhance characterization of patients. RESULTS: After adjustment, patients with emotional hyper-reactivity (n = 306) had significantly higher levels of systolic and diastolic blood pressure (P < 1.0 × 10-8 ), high-sensitivity C-reactive protein (P < 1.0 × 10-8 ), fasting glucose (P < 2.23 × 10-6 ), glycated hemoglobin (P = 0.0008) and suicide attempts (P = 1.4 × 10-8 ). Using models of combined clinical and biological factors for distinguishing BD patients with and without emotional hyper-reactivity, the strongest predictors were: systolic and diastolic blood pressure, fasting glucose, C-reactive protein and number of suicide attempts. This predictive model identified patients with emotional hyper-reactivity with 84.9% accuracy. CONCLUSION: The assessment of emotional hyper-reactivity in remitted BD patients is clinically relevant, particularly for identifying those at higher risk of cardiometabolic dysfunction, chronic inflammation, and suicide.

Sleep quality and emotional reactivity cluster in bipolar disorders and impact on functioning.

OBJECTIVE: Bipolar disorders (BD) are characterized by sleep disturbances and emotional dysregulation both during acute episodes and remission periods. We hypothesized that sleep quality (SQ) and emotional reactivity (ER) defined clusters of patients with no or abnormal SQ and ER and we studied the association with functioning. METHOD: We performed a bi-dimensional cluster analysis using SQ and ER measures in a sample of 533 outpatients patients with BD (in remission or with subsyndromal mood symptoms). Clusters were compared for mood symptoms, sleep profile and functioning. RESULTS: We identified three clusters of patients: C1 (normal ER and SQ, 54%), C2 (hypo-ER and low SQ, 22%) and C3 (hyper-ER and low SQ, 24%). C1 was characterized by minimal mood symptoms, better sleep profile and higher functioning than other clusters. Although highly different for ER, C2 and C3 had similar levels of subsyndromal mood symptoms as assessed using classical mood scales. When exploring sleep domains, C2 showed poor sleep efficiency and a trend for longer sleep latency as compared to C3. Interestingly, alterations in functioning were similar in C2 and C3, with no difference in any of the sub-domains. CONCLUSION: Abnormalities in ER and SQ delineated three clusters of patients with BD and significantly impacted on functioning.

Childhood trauma, dimensions of psychopathology and the clinical expression of bipolar disorders: A pathway analysis.

BACKGROUND: This study aims at testing for paths from childhood abuse to clinical indicators of complexity in bipolar disorder (BD), through dimensions of affective dysregulation, impulsivity and hostility. METHOD: 485 euthymic patients with BD from the FACE-BD cohort were included from 2009 to 2014. We collect clinical indicators of complexity/severity: age and polarity at onset, suicide attempt, rapid cycling and substance misuse. Patients completed questionnaires to assess childhood emotional, sexual and physical abuses, affective lability, affect intensity, impulsivity, motor and attitudinal hostility. RESULTS: The path-analysis demonstrated significant associations between emotional abuse and all the affective/impulsive dimensions (p < 0.001). Sexual abuse was moderately associated with emotion-related dimensions but not with impulsivity nor motor hostility. In turn, affect intensity and attitudinal hostility were associated with high risk for lifetime presence of suicide attempts (p < 0.001), whereas impulsivity was associated with a higher risk of lifetime presence of substance misuse (p < 0.001). No major additional paths were identified when including Emotional and Physical Neglect in the model. CONCLUSIONS: This study provides refinement of the links between early adversity, dimensions of psychopathology and the complexity/severity of BD. Mainly, dimensions of affective dysregulation, impulsivity/hostility partially mediate the links between childhood emotional to suicide attempts and substance misuse in BD.

[French Society for Biological Psychiatry and Neuropsychopharmacology and Fondation FondaMental task force: Formal Consensus for the management of treatment-resistant depression]. / Prise en charge des troubles dépressifs résistants : recommandations françaises formalisées par des experts de l'AFPBN et de la fondation FondaMental.

Major depression represents among the most frequent psychiatric disorders in the general population with an estimated lifetime prevalence of 16-17%. It is characterized by high levels of comorbidities with other psychiatric conditions or somatic diseases as well as a recurrent or chronic course in 50 to 80% of the cases leading to negative repercussions on the daily functioning, with an impaired quality of life, and to severe direct/indirect costs. Large cohort studies have supported that failure of a first-line antidepressant treatment is observed in more than 60% of patients. In this case, several treatment strategies have been proposed by classical evidence-based guidelines from internationally recognized scientific societies, referring primarily on: I) the switch to another antidepressant of the same or different class; II) the combination with another antidepressant of complementary pharmacological profile; III) the addition of a wide range of pharmacological agents intending to potentiate the therapeutic effects of the ongoing antidepressant medication; IV) the association with appropriate psychological therapies; and, V) the use of non-invasive brain stimulation techniques. However, although based on the most recently available data and rigorous methodology, standard guidelines have the significant disadvantage of not covering a large variety of clinical conditions, while currently observed in everyday clinical practice. From these considerations, formalized recommendations by a large panel of French experts in the management of depressed patients have been developed under the shared sponsorship of the French Association of Biological Psychiatry and Neuropsychopharmacology (AFPBN) and the Fondation FondaMental. These French recommendations are presented in this special issue in order to provide relevant information about the treatment choices to make, depending particularly on the clinical response to previous treatment lines or the complexity of clinical situations (clinical features, specific populations, psychiatric comorbidities, etc.). Thus, the present approach will be especially helpful for the clinicians enabling to substantially facilitate and guide their clinical decision when confronted to difficult-to-treat forms of major depression in the daily clinical practice. This will be expected to significantly improve the poor prognosis of the treatment-resistant depression thereby lowering the clinical, functional and costly impact owing directly to the disease.

Affect lability predicts occurrence of suicidal ideation in bipolar patients: a two-year prospective study.

OBJECTIVE: The aim of our study was to investigate, in bipolar patients, whether affect lability was associated with suicidal ideation incidence during 2-year follow-up, and which subtype of affect lability was associated with suicidal ideation. METHOD: A total of 319 euthymic or mildly depressed bipolar outpatients recruited in the French FondaMental Advanced Centres of Expertise for Bipolar Disorder were divided into two subgroups according to the occurrence of suicidal ideation during a 2-year follow-up. Affect lability was assessed by the French version of the Affect Lability Scale. RESULTS: Bipolar patients with high affect lability were more likely to report suicidal ideation during follow-up, even after adjustment for age, study level, rapid cycling, current depression level, anxiety disorder, and lifetime history SA (OR = 2.47; 95% CI [1.15-5.30], P = 0.01). The risk of suicidal ideation increased with the level of affect lability. More specifically, the propensity to switch from neutral to elation affect, from anxious to depressive affect (or inversely), and from neutral to anger affect predicted suicidal ideation. CONCLUSION: Reducing affective lability could become a new therapeutic target of suicidal prevention in bipolar disorder.

Modulation of motor inhibition by subthalamic stimulation in obsessive-compulsive disorder.

High-frequency deep brain stimulation of the subthalamic nucleus can be used to treat severe obsessive-compulsive disorders that are refractory to conventional treatments. The mechanisms of action of this approach possibly rely on the modulation of associative-limbic subcortical-cortical loops, but remain to be fully elucidated. Here in 12 patients, we report the effects of high-frequency stimulation of the subthalamic nucleus on behavior, and on electroencephalographic responses and inferred effective connectivity during motor inhibition processes involved in the stop signal task. First, we found that patients were faster to respond and had slower motor inhibition processes when stimulated. Second, the subthalamic stimulation modulated the amplitude and delayed inhibition-related electroencephalographic responses. The power of reconstructed cortical current densities decreased in the stimulation condition in a parietal-frontal network including cortical regions of the inhibition network such as the superior parts of the inferior frontal gyri and the dorsolateral prefrontal cortex. Finally, dynamic causal modeling revealed that the subthalamic stimulation was more likely to modulate efferent connections from the basal ganglia, modeled as a hidden source, to the cortex. The connection from the basal ganglia to the right inferior frontal gyrus was significantly decreased by subthalamic stimulation. Beyond motor inhibition, our study thus strongly suggests that the mechanisms of action of high-frequency subthalamic stimulation are not restricted to the subthalamic nucleus, but also involve the modulation of distributed subcortical-cortical networks.

Effect of early trauma on the sleep quality of euthymic bipolar patients.

OBJECTIVE: Poor quality of sleep is frequent in euthymic bipolar patients and conveys worse clinical outcomes. We investigated the features of euthymic bipolar patients associated with poor sleep quality, with a focus on the effect of childhood trauma. METHOD: 493 euthymic patients with DSM-IV-defined bipolar disorders were recruited in FondaMental Advanced Centers of Expertize for Bipolar Disorders (FACE-BD) between 2009 and 2014. Clinical variables were recorded. Subjective sleep quality and history of childhood trauma were respectively measured by the Pittsburgh Sleep Quality Index (PSQI) and the Childhood Trauma Questionnaire (CTQ). RESULTS: Poor sleepers were older, less professionally active, had significantly higher anxiety levels, took more anxiolytic drugs and did endorse more suicide attempts and suicidal ideas than good sleepers after adjusting for anxiety levels and age. Emotional abuse was associated with poor sleep quality after adjustment for BMI, age, professional activity, and bipolar disorders (BD) type (OR=1.83; 95% CI [1.30; 3.10]; p=0.02). However, this association was lost after adjustment for anxiety levels, anxiolytic treatment and suicide ideation/attempts. LIMITATIONS: The main limitation was the type of sleep assessment, which only measured the subjective part of sleep complaints. CONCLUSION: A history of emotional abuse might underlie sleep problems in many bipolar patients but anxiety seems to act as a confounding factor in this relationship. New studies are needed to elucidate the role of childhood maltreatment on poor sleep among bipolar patients.

Increased risk of suicide attempt in bipolar patients with severe tobacco dependence.

BACKGROUND: The aim of our study was to investigate, in bipolar patients, the association between tobacco status (use and dependence) and history of suicide attempt, and to assess the possible role of inflammation as a missing link in the association between smoking status and history of suicide attempt. METHODS: A total of 453 adult bipolar out-patients recruited in the French FondaMental Advanced Centres of Expertise for Bipolar Disorder were divided into two subgroups: 274 patients without past history of suicide attempt (non-SA), and 179 patients with a past history of suicide attempt (SA). Tobacco use and dependence, psychiatric and somatic comorbidities, history of childhood abuse, family history of suicide were assessed. Fasting blood tests yielded samples collected for the measurement of high sensitivity (hs-)CRP. RESULTS: The risk of suicide attempt increased with smoking dependence. Notably, bipolar patients with a history of suicide attempt were three times more likely to have severe tobacco dependence, independently of confounding factors. However, we failed to find arguments promoting the hypothesis of inflammatory markers (through hs-CRP measure) in the link between tobacco dependence and suicidal behavior. CONCLUSIONS: We found a significant association between severe tobacco dependence and history of suicide attempt, but not with level of CRP, independently of confusing factors. Longitudinal studies taken into account all these potential confusing factors are needed to confirm our results.

Clinical and neuropsychological characteristics of euthymic bipolar patients having a history of severe suicide attempt.

OBJECTIVE: Identifying bipolar patients at high-suicide risk is a major health issue. To improve their identification, we compared dimensional and neuropsychological profile of bipolar patients with or without history of suicide attempt, taking into account suicidal severity (i.e. admission to intensive ward). METHOD: A total of 343 adult euthymic bipolar out-patients recruited in the French FondaMental Advanced Centres of Expertise for Bipolar Disorder were divided into three subgroups: 214 patients without history of suicide attempt, 88 patients with past history of non-severe suicide attempt and 41 patients with past history of severe suicide attempt. General intellectual functioning, speed of information processing, verbal learning and memory, verbal fluency and executive functioning were assessed. RESULTS: Severe suicide attempters had lower affective intensity and lability than non-severe attempters. Severe suicide attempters outperformed non-severe attempters for verbal learning and non-attempters for Stroop word reading part after adjustment for study centre, age, gender, educational level, antipsychotics use, depression score, anxious and addictive comorbidities. CONCLUSION: Neuropsychological tasks commonly used to assess bipolar patients do not seem accurate to identify suicide attempters in euthymic patients. In the future, decision-making and emotional recognition tasks should be assessed. Moreover, clinical and neuropsychological profiles should be considered together to better define suicidal risk.

Risk factors for treatment resistance in unipolar depression: a systematic review.

BACKGROUND: Treatment resistant depression is a complex disorder and an important source of morbidity and mortality. Identification of risk factors of resistance may be useful to improve early recognition as well as treatment selection and prediction of outcome in patients with depression. METHODS: The aim of this paper was to review the current status of knowledge regarding risk factors of treatment resistance in unipolar depression, in patients who failed to respond to at least two successive and adequate antidepressant treatments. RESULTS: Systematic literature search yielded 8 publications exploring clinical and biological factors. Specific psychiatric comorbidities, psychosocial factors, clinical characteristics of the depressive episode and biological markers emerge as possible risk factor for treatment resistant depression. LIMITATIONS: Due to the lack of objective definition and diagnostic criteria for treatment resistant depression, and the paucity of reports on risk factors, our review only summarized a small number of studies. CONCLUSION: Future investigations of risk factors should help to improve the understanding of the mechanisms underlying resistance in mood disorders and contribute to improve their therapeutic management.

Inhibitory control and error monitoring by human subthalamic neurons.

The subthalamic nucleus (STN) has been shown to be implicated in the control of voluntary action, especially during tasks involving conflicting choice alternatives or rapid response suppression. However, the precise role of the STN during nonmotor functions remains controversial. First, we tested whether functionally distinct neuronal populations support different executive control functions (such as inhibitory control or error monitoring) even within a single subterritory of the STN. We used microelectrode recordings during deep brain stimulation surgery to study extracellular activity of the putative associative-limbic part of the STN while patients with severe obsessive-compulsive disorder performed a stop-signal task. Second, 2-4 days after the surgery, local field potential recordings of STN were used to test the hypothesis that STN oscillations may also reflect executive control signals. Extracellular recordings revealed three functionally distinct neuronal populations: the first one fired selectively before and during motor responses, the second one selectively increased their firing rate during successful inhibitory control, and the last one fired selectively during error monitoring. Furthermore, we found that beta band activity (15-35 Hz) rapidly increased during correct and incorrect behavioral stopping. Taken together, our results provide critical electrophysiological support for the hypothesized role of the STN in the integration of motor and cognitive-executive control functions.

Chronotypes of bipolar patients in remission: validation of the French version of the circadian type inventory in the FACE-BD sample.

Circadian rhythm disturbances have been associated with bipolar disorder (BD) during both the mood episodes and the periods of remission. Circadian phase preferences for the evening have been reported for remitted patients, whereas the amplitude and stability of their rhythms have never been assessed using questionnaires. The primary aim of our study was the validation of a French version of the Circadian Type Inventory (CTI), whereas its secondary aim was the comparison between remitted patients with BD and healthy controls for rhythm stability and amplitude and for phase preference. For this purpose, we used the CTI and the Composite Scale of Morningness (CSM) that assesses phase preference ("morning" or "evening" type). First, we report here on the validation of the French version of the 11-item Circadian Type Inventory in a sample of 140 remitted patients with BD and 156 healthy controls. Principal components analysis revealed a two-factor structure (FR: flexibility/rigidity scale corresponding to rhythm stability; LV: languid/vigorous scale corresponding to rhythm amplitude) explaining 52% of the variance in the control group and 47% in the bipolar group. Cronbach's alpha was 0.75 for FR and 0.73 for LV. The test-retest reliability was 0.74 for FR and 0.86 for LV (3 wks) and 0.62 for FR and 0.72 for LV (6 mos). LV and FR scores correlated with the Composite Scale of Morningness score (p < 0.00001 and p = 0.0002, respectively). Second, as compared with controls, patients with BD were more languid (p < 0.00001) and showed an evening preference (p = 0.0003), but they did not differ from the controls with regard to flexibility/rigidity. The French version of the CTI appeared to have satisfactory psychometrics characteristics. Bipolar patients exhibited not only abnormalities in phase preference but also in amplitude as measured by languidity. Since circadian rhythm dysfunction has been shown to predict poor functioning and mood relapses in interepisodic patients with BD, this tool would appear to be a promising, easy-to-use, measure of the amplitude and flexibility of circadian rhythms that could enrich the arsenal of assessments used in clinical settings.

Clinical features associated with trait-impulsiveness in euthymic bipolar disorder patients.

BACKGROUND: A strong association has been reported between trait-impulsiveness and bipolar disorder (BD). Much attention has been focused on this association, but subgroup analysis has generated conflicting results, raising questions about the role of trait-impulsiveness in suicidal behavior and substance misuse in bipolar patients. METHOD: We compared Barratt Impulsiveness Scale-10 scores between 385 euthymic bipolar patients and 185 healthy controls. We then investigated possible association between impulsiveness scores and the following clinical characteristics: suicide attempt (SA), lifetime alcohol/cannabis misuse, rapid cycling and mixed episodes. RESULTS: Bipolar patients and healthy controls had significantly different BIS-10 total score and subscores (motor, attentional and nonplanning impulsiveness) (all p values <0.0001). No association was observed between BIS-10 total score, personal history of SA, number of SA, age at first SA and history of violent SA. Higher BIS-10 total scores were associated with alcohol misuse (p=0.005), cannabis misuse (p<0.0001), with an additive effect for these two substances (p=0.005). Higher BIS-10 total scores were also associated with rapid cycling (p=0.006) and history of mixed episodes (p=0.002), with an additive effect of these two variables (p=0.0006). LIMITATIONS: We used only one clinical measurement of impulsiveness and did not carry out cognitive assessment. CONCLUSION: This study demonstrates that trait-impulsiveness may be considered as a dimensional feature associated with BD and with a more severe clinical expression of the disease, characterized by a history of substance misuse, rapid cycling and mixed episodes. We found no association between impulsiveness and SA characteristics in bipolar patients, confirming some previous negative results.

An fMRI study of the social competition in healthy subjects.

Social interaction requires the ability to infer another person's mental state (Theory of Mind, ToM) and also executive functions. This fMRI study aimed to identify the cerebral correlates activated by ToM during a specific social interaction, the human-human competition. In this framework, we tested a conflict resolution task (Stroop) adapted to a virtual situation of competition. The participants were instructed to play in order to win either against a human-like competitor (human-human competition) or against a non-human competitor (human-machine competition). Only the human-human competition requires ToM as this type of competition is performed under social interaction. We identified first the classical network of executive regions activated by Stroop. Secondly, we identified the social (human-human) competition regions, represented by the bilateral superior and inferior frontal gyri, the anterior cingulate, the insula, the superior and anterior temporal, the hippocampus, the fusiform gyrus, the cuneus and the precuneus. Finally, we identified the executive regions that were modulated by the human-human competition, i.e., the executive control regions additionally activated when mentalizing in the context of social competition. They constituted a network predominant to the right and composed of the superior and middle frontal, anterior cingulate, insula and fusiform gyrus. We suggest that our experimental paradigm may be useful in exploration of the cerebral correlates of social adjustments in several situations such as psychiatric disorders presenting executive and social dysfunctions.