Jean-Louis Nandrino

Depression as a dynamical disease

Mathematical models are helpful in the understanding of diseases through the use of dynamical indicators. A previous study has shown that brain activity can be characterized by a decrease of dynamical complexity in depressive subjects. The present paper confirms and extends these conclusions through the use of recent methodological advances: first episode and recurrent patients strongly differ in their dynamical response to therapeutic interventions. These results emphasize the need for clinical follow-ups to avoid recurrence and the necessity of specific therapeutic intervention in the case of recurrent patients.

Decrease of complexity in EEG as a symptom of depression.

Nonlinear dynamic analysis provides new methods for the processing of the electroencephalogram (EEG). We demonstrate here that the EEG dynamics of major depressive subjects is more predictable, that is less complex, than that of control subjects. Moreover, the consequence of treatment upon the EEG dynamics seems to be dependent on the appearance of the illness. Although the specificity of this dynamic signature for different stages of depression is to be confirmed, the assumption of a strong link between a healthy system and a high level of complexity in dynamics is further supported.

Autobiographical Memory in Major Depression: A Comparison between First-Episode and Recurrent Patients

Autobiographical memory in depression is characterized by an increase in general memory evocation. The aim of this study is to compare autobiographical memory in patients with a first depressive episode and in recurrent patients before and after recovery, using Williams’ and Scott’s autobiographical memory test. Our results show an increase of the number of general memories only with positive cue words in both groups of patients during the depressive episode. After clinical improvement, this specificity remains in recurrent patients who, in addition, recall more general memories for negative words. By contrast, patients with a first depressive episode are no longer different from controls. These results show both an overgeneralization and a deficit in positive memory access during the depressive episode, whatever the number of previous episodes. Moreover, recurrence chronically modifies access to emotional memories.

Autobiographical memory decline in Alzheimer's disease, a theoretical and clinical overview.

Autobiographical memory, or memory for personal experiences, allows individuals to define themselves and construct a meaningful life story. Decline of this ability, as observed in Alzheimers disease (AD), results in an impaired sense of self and identity. In our model (AMAD: Autobiographical Memory in Alzheimers Disease), we present a critical review of theories and findings regarding cognitive and neuroanatomical underpinnings of autobiographical memory and its decline in AD and highlight studies on its clinical rehabilitation. We propose that autobiographical recall in AD is mainly characterized by loss of associated episodic information, which leads to de-contextualization of autobiographical memories and a shift from reliving past events to a general sense of familiarity. This decline refers to retrograde, but also anterograde amnesia that affects newly acquired memories besides remote ones. One consequence of autobiographical memory decline in AD is decreased access to memories that shape self-consciousness, self-knowledge, and self-images, leading to a diminished sense of self and identity. The link between autobiographical decline and compromised sense of self in AD can also manifest itself as low correspondence and coherence between past memories and current goals and beliefs. By linking cognitive, neuroanatomical, and clinical aspects of autobiographical decline in AD, our review provides a theoretical foundation, which may lead to better rehabilitation strategies.

Time for reorienting of attention: A premotor hypothesis of the underlying mechanism.

The paradigm of the covert orienting of attention (COA) has shown that the displacement of visual attention may be assessed even in the absence of eye movement. Stimuli correctly cued before their presentation are usually detected faster than uncued stimuli. However, miscued stimuli induce an increased detection time, which has been attributed to the time required for the reorientation of attention from the incorrect to the correct spatial location. Currently, the mechanism of such a displacement of visual attention remains unknown. Rizzolatti et al. Neuropsychologia 25, 31-40 (1987) have suggested a premotor hypothesis which suggests that an oculomotor disprogramming and reprogramming is necessary to reorient visual attention, even if the eye movement is inhibited. Since shifting of auditory attention from one ear to the other does not require any motor control, we further investigated the model of COA in 20 normal subjects who performed two tasks requiring a reorienting of auditory attention: (1) a choice RT task that requires a response readjustment during the auditory reorienting; (2) a simple RT task that does not require a response readjustment during the auditory reorienting; (2) a simple RT task that does not require a response readjustment during the auditory reorienting. Results indicate that correctly cued stimuli significantly reduce the RT in both tasks and that this reduction is greater in the choice than in the simple RT task. This suggests that a correct cue may produce a pre-programming of the response, in addition to the pre-engagement of the perceptual attention.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of emotion regulation difficulties on the tonic and phasic cardiac autonomic response.

Background Emotion regulation theory aims to explain the interactions between individuals and the environment. In this context, Emotion Regulation Difficulties (ERD) disrupt the physiological component of emotions through the autonomic nervous system and are involved in several psychopathological states. Objective We were interested in comparing the influence of a film-elicited emotion procedure on the autonomic nervous system activity of two groups with different levels of emotion regulation difficulties. Methods A total of 63 women (undergraduate students) ranging from 18 to 27 (20.7±1.99) years old were included. Using the upper and lower quartile of a questionnaire assessing the daily difficulties in regulating emotions, two groups, one with low (LERD) and one with high (HERD) levels of emotion regulation difficulties, were constituted and studied during a film-elicited emotion procedure. Cardiac vagal activity (HF-HRV) was analyzed during three periods: baseline, film-elicited emotion, and recovery. Results The cardiovascular results showed a decrease in HF-HRV from baseline to elicitation for both groups. Then, from elicitation to recovery, HF-HRV increased for the LERD group, whereas a low HF-HRV level persisted for the HERD group. Conclusions The HERD group exhibited inappropriate cardiac vagal recovery after a negative emotion elicitation had ended. Cardiac vagal tone took longer to return to its initial state in the HERD group than in the LERD group. Prolonged cardiac vagal suppression might constitute an early marker of emotion regulation difficulties leading to lower cardiac vagal tone.

Self-defining memories during exposure to music in Alzheimer's disease

BACKGROUND Research suggests that exposure to music may enhance autobiographical recall in Alzheimers Disease (AD) patients. This study investigated whether exposure to music could enhance the production of self-defining memories, that is, memories that contribute to self-discovery, self-understanding, and identity in AD patients. METHODS Twenty-two mild-stage AD patients and 24 healthy controls were asked to produce autobiographical memories in silence, while listening to researcher-chosen music, and to their own-chosen music. RESULTS AD patients showed better autobiographical recall when listening to their own-chosen music than to researcher-chosen music or than in silence. More precisely, they produced more self-defining memories during exposure to their own-chosen music than to researcher-chosen music or during silence. Additionally, AD patients produced more self-defining memories than autobiographical episodes or personal-semantics during exposure to their own-chosen music. This pattern contrasted with the poor production of self-defining memories during silence or during exposure to researcher-chosen music. Healthy controls did not seem to enjoy the same autobiographical benefits nor the same self-defining memory enhancement in the self-chosen music condition. CONCLUSIONS Poor production of self-defining memories, as observed in AD, may somehow be alleviated by exposure to self-chosen music.

Development and validation of the Cognitive Inventory of subjective distress.

Objectives This study was aimed at exploring some of the facets of psychological distress during aging, and at validating an inventory, the Cognitive Inventory of Subjective Distress (CISD) for assessing this kind of distress.

Decrease of Mutual Information in Brain Electrical Activity of Patients with Relapsing-Remitting Multiple Sclerosis

The disturbance of cortical communication has been hypothesized as an important factor in the appearance of cognitive impairment in (MS). Cortical communication is quantified here in control subjects and patients with relapsing-remitting multiple sclerosis (RRMS) on the basis of mean coherence in the δ, θ, α, β and γ bands and using mutual information computed between pairs of bipolar EEG signals recorded during resting condition. Each patient received also a cognitive assessment using a battery of neuropsychological tests specific to cognitive deficits in MS. No difference was observed for the coherence indices whereas inter-hemispheric and right hemisphere mutual information is significantly lower in patients with MS than in control subjects. Moreover, inter-hemispheric mutual information decrease significantly with illness duration and right mutual information differentiate cognitively deficient and non-deficient patients. Mutual information allows to quantify the cortical communication in patients with RRMS and is related to clinical characteristics. Cortical communication quantified in a resting state might be a potential marker for the neurological damage induced by RRMS.

A case-comparison study of executive functions in alcohol-dependent adults with maternal history of alcoholism

INTRODUCTION As executive dysfunctions frequently accompany alcohol dependence, we suggest that reports of executive dysfunction in alcoholics are actually due, in some case to a maternal history of alcohol misuse (MHA+). A history of maternal alcohol dependence increases the risk for prenatal alcohol exposure to unborn children. These exposures likely contribute to executive dysfunction in adult alcoholics. To assess this problem, we propose a case-comparison study of alcohol-dependent subjects with and without a MHA. METHODS Ten alcohol-dependent subjects, with a maternal history of alcoholism (MHA) and paternal history of alcoholism (PHA), were matched with 10 alcohol-dependent people with only a paternal history of alcoholism (PHA). Executive functions (cancellation, Stroop, and trail-making A and B tests) and the presence of a history of three mental disorders (attention deficit hyperactivity disorder, violent behavior while intoxicated, and suicidal behavior) were evaluated in both populations. RESULTS Alcohol-dependent subjects with MHA showed a significant alteration in executive functions and significantly more disorders related to these functions than PHA subjects. The major measures of executive functioning deficit are duration on task accomplishment in all tests. Rates of ADHD and suicidality were found to be higher in MHA patients compared to the controls. CONCLUSION A history of MHA, because of the high risk of PAE (in spite of the potential confounding factors such as environment) must be scrupulously documented when evaluating mental and cognitive disorders in a general population of alcoholics to ensure a better identification of these disorders. It would be helpful to replicate the study with more subjects.