La contribution de la réactivité comportementale, de la sensibilité maternelle et du contrôle parental à la prédiction de l'anxiété à la petite enfance chez les enfants de mères adolescentes

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

De la maltraitance à l’enfance aux comportements d’agression à l’âge adulte : quel est le rôle de la réactivité émotionnelle et comportementale?

En dépit des efforts déployés pour diminuer la prévalence de la maltraitance à l’enfance, celle-ci serait associée à des difficultés non négligeables, dont la manifestation d’agression. La réactivité émotionnelle et comportementale, incluant la colère, la peur et l’évitement, est proposée comme mécanisme expliquant la relation unissant la maltraitance à l’agression. Quatre objectifs sont poursuivis à cette fin, soit d’examiner la relation notée entre: (1) la maltraitance et l’agression, (2) la maltraitance et la colère, la peur, ainsi que l’évitement, (3) la colère, la peur, ainsi que l’évitement et l’agression et (4) tester formellement le rôle médiateur et modérateur de la colère, la peur et l’évitement à cette relation. Les données de 160 hommes âgés de 18 à 35 ans ayant été exposés ou non à de la maltraitance ont été colligées par le biais de questionnaires et d’une tâche de provocation sociale permettant de mesurer les expressions faciales de colère et de peur, ainsi que les comportements d’évitement. Les résultats suggèrent que la maltraitance et les comportements d’évitement sont associés à l’agression. La maltraitance ne serait toutefois pas liée à la colère, à la peur et à l’évitement. Alors que les résultats suggèrent que ces indices n’aient pas de rôles médiateurs dans la relation entre la maltraitance et l’agression, la réactivité aux plans de la colère et de l’évitement magnifierait cette relation. Ainsi, les résultats invitent à prendre en compte les expériences de maltraitance et l’intensité de la réactivité émotionnelle et comportementale dans les interventions afin de cibler les individus plus à risque d’avoir recours à l’agression.

De la maltraitance à l’enfance aux comportements d’agression à l’âge adulte : quel est le rôle de la réactivité émotionnelle et comportementale?

En dépit des efforts déployés pour diminuer la prévalence de la maltraitance à l’enfance, celle-ci serait associée à des difficultés non négligeables, dont la manifestation d’agression. La réactivité émotionnelle et comportementale, incluant la colère, la peur et l’évitement, est proposée comme mécanisme expliquant la relation unissant la maltraitance à l’agression. Quatre objectifs sont poursuivis à cette fin, soit d’examiner la relation notée entre: (1) la maltraitance et l’agression, (2) la maltraitance et la colère, la peur, ainsi que l’évitement, (3) la colère, la peur, ainsi que l’évitement et l’agression et (4) tester formellement le rôle médiateur et modérateur de la colère, la peur et l’évitement à cette relation. Les données de 160 hommes âgés de 18 à 35 ans ayant été exposés ou non à de la maltraitance ont été colligées par le biais de questionnaires et d’une tâche de provocation sociale permettant de mesurer les expressions faciales de colère et de peur, ainsi que les comportements d’évitement. Les résultats suggèrent que la maltraitance et les comportements d’évitement sont associés à l’agression. La maltraitance ne serait toutefois pas liée à la colère, à la peur et à l’évitement. Alors que les résultats suggèrent que ces indices n’aient pas de rôles médiateurs dans la relation entre la maltraitance et l’agression, la réactivité aux plans de la colère et de l’évitement magnifierait cette relation. Ainsi, les résultats invitent à prendre en compte les expériences de maltraitance et l’intensité de la réactivité émotionnelle et comportementale dans les interventions afin de cibler les individus plus à risque d’avoir recours à l’agression.

Amphetamine modulates cellular recruitment and airway reactivity in a rat model of allergic lung inflammation

Asthma is characterized by pulmonary cellular infiltration, vascular exudation and airway hyperresponsiveness. Several drugs that modify central nervous system (CNS) activity can modulate the course of asthma. Amphetamine (AMPH) is a highly abused drug that presents potent stimulating effects on the CNS and has been shown to induce behavioral, biochemical and immunological effects. The purpose of this study was to investigate the effects of AMPH on pulmonary cellular influx, vascular permeability and airway reactivity. AMPH effects on adhesion molecule expression, IL-10 and IL-4 release and mast cell degranulation were also studied. Male Wistar rats were sensitized with ovalbumin (OVA) plus alum via subcutaneous injection. One week later, the rats received another injection of OVA-alum (booster). Two weeks after this booster, the rats were subjected to AMPH treatment 12 h prior to the OVA airway challenge. In rats treated with AMPH, the OVA challenge reduced cell recruitment into the lung, the vascular permeability and the cellular expression of ICAM-1 and Mac-1. Additionally, elevated levels of IL-10 and IL-4 were found in samples of lung explants from allergic rats. AMPH treatment, in comparison, increased IL-10 levels but reduced those of IL-4 in the lung explants. Moreover, the tracheal responsiveness to methacholine (MCh), as well as to an in vitro OVA challenge, was reduced by AMPH treatment, and levels of PCA titers were not modified by the drug. Our findings suggest that single AMPH treatment down-regulates several parameters of lung inflammation, such as cellular migration, vascular permeability and tracheal responsiveness. These results also indicate that AMPH actions on allergic lung inflammation include endothelium-leukocyte interaction mechanisms, cytokine release and mast cell degranulation. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Pain and distress reactivity and recovery as early predictors of temperament in toddlers born preterm

Background: Pain reactivity may reflect underlying mechanisms of constitutional aspects of temperament. Aim: To examine whether the neonatal biobehavioral reactivity and recovery responses from pain and distress, as well as the gestational age, the illness severity and the amount of painful procedures undergone the Neonatal Intensive Care Unit (NICU) stay, predict temperament later in toddlerhood, in vulnerable children born preterm. Study design: Prospective-longitudinal study. Subjects: Twenty-six preterm and very low birth weight infants followed from birth to toddlerhood. Outcome measures: Illness severity was assessed with the Clinical Risk Index for Babies (CRIB) score. The medical charts were reviewed prospectively for obtaining the amount of pain exposure in NICU. For assessing the behavioral and cardiac reactivity and recovery from pain and distress, the neonates were evaluated during routine blood collection in the NICU in the first 10 days of life. Pain and distress reactivity and recovery was measured using the Neonatal Facial Coding System score, the duration of crying. and the magnitude of average heart rate. At toddlerhood, mothers answered the Early Childhood Behavior Questionnaire. Results: Higher biobehavioral reactivity to pain and distress predicted higher temperamental Negative Affect, above and beyond gestational age, illness severity and amount of pain exposure in NICU. However, we did not find a predictive relation between gestational age, CRIB score and number of painful procedures undergone NICU and toddler`s temperament. Conclusions: The findings highlight the relevance of the neonatal individual characteristics of reactivity for identifying more vulnerable infants for future problems in biobehavioral regulation. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Personality, Brain Asymmetry, and Neuroendocrine Reactivity in Two Immune-Mediated Disorders: a Preliminary Report

Development of some immune-mediated disorders may depend on dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. To explore neuropsychologic mechanisms in relation to the abnormal endocrine reactivity in patients with systemic lupus erythematosus (SLE) and chronic hepatitis C (CHC) we used the corticotropin releasing hormone (CRH) test, the Minnesota Multiphasic Personality Inventory (MMPI), and the Edinburgh Inventory of Manual Preference Inventory (EIMP). Compared to controls, the adrenocorticotrophic hormone (ACTH) response to CRH was reduced in CHC, while SLE presented reduced baseline dehydroepiandrosterone sulfate levels; higher neurotic scores were found in SLE and higher behavior deviant scores in CHC. Peak ACTH levels were a significant factor for the MMPI profile variability, while the manual preference score was a significant factor for the ACTH response. Personality and manual preference contribute to neuroendocrine abnormalities. Different behavioral and neuroimmunoendocrine models emerge for these disorders.

Infants’ behavioral and physiological profile and mother–infant interaction

This study aims to (a) identify and profile groups of infants according to their behavioral and physiological characteristics, considering their neurobehavioral organization, social withdrawal behavior, and endocrine reactivity to stress, and to (b) analyze group differences in the quality of mother–infant interaction. Ninety seven 8-week-old infants were examined using the Neonatal Behavioral Assessment Scale and the Alarm Distress Baby Scale. Cortisol levels were measured both before and after routine inoculation between 8 and 12 weeks. At 12 to 16 weeks mother–infant interaction was assessed using the Global Rating Scales of Mother–Infant Interaction. Three groups of infants were identified: (a) ‘‘withdrawn’’; (b) ‘‘extroverted’’; (c) ‘‘underaroused.’’ Differences between them were found regarding both infant and mother behaviors in the interaction and the overall quality of mother–infant interaction. The identification of behavioral and physiological profiles in infants is an important step in the study of developmental pathways.

A behavioral study of alpha-1b adrenergic receptor knockout mice: increased reaction to novelty and selectively reduced learning capacities.

Knockout mice lacking the alpha-1b adrenergic receptor were tested in behavioral experiments. Reaction to novelty was first assessed in a simple test in which the time taken by the knockout mice and their littermate controls to enter a second compartment was compared. Then the mice were tested in an open field to which unknown objects were subsequently added. Special novelty was introduced by moving one of the familiar objects to another location in the open field. Spatial behavior and memory were further studied in a homing board test, and in the water maze. The alpha-1b knockout mice showed an enhanced reactivity to new situations. They were faster to enter the new environment, covered longer paths in the open field, and spent more time exploring the new objects. They reacted like controls to modification inducing spatial novelty. In the homing board test, both the knockout mice and the control mice seemed to use a combination of distant visual and proximal olfactory cues, showing place preference only if the two types of cues were redundant. In the water maze the alpha-1b knockout mice were unable to learn the task, which was confirmed in a probe trial without platform. They were perfectly able, however, to escape in a visible platform procedure. These results confirm previous findings showing that the noradrenergic pathway is important for the modulation of behaviors such as reaction to novelty and exploration, and suggest that this is mediated, at least partly, through the alpha-1b adrenergic receptors. The lack of alpha-1b adrenergic receptors in spatial orientation does not seem important in cue-rich tasks but may interfere with orientation in situations providing distant cues only.

Emotional reactivity at 12 months in very preterm infants born at <29 weeks of gestation.

The present study evaluated the socio-emotional development of very preterm born infants at 12 months corrected age. Forty-one infants born very preterm (<29 weeks of gestation) were compared to 22 infants born full term on a standardized behavioral assessment and a parental temperament questionnaire, both measuring emotional reactivity to joy, anger and fear, as well as sustained attention. The behavioral assessment showed that very preterm infants exhibited as much joy as full term infants during a joy-eliciting episode. However, they expressed a significantly higher reactivity in anger-eliciting situations and a reduced reactivity toward fear-eliciting situations. For all three emotion-eliciting situations, the preterm infants reacted with a higher level of motor activity. The preterm infants also exhibited a distinct attention pattern with a significantly higher initial attention level which declined rapidly throughout the episode. The questionnaire did not show any group differences. The clinical relevance of these results in terms of preliminary hallmarks of later behavioral difficulties such attention deficit/hyperactivity disorder are discussed as well as the inconsistencies observed between the questionnaire and the behavioral assessment.

Decreased behavioral impairments in an Alzheimer mice model by interfering with TNF-alpha metabolism.

The performance of mice expressing PDAPP (+/+ or +/-) was studied in the Morris place navigation task. Different lines of questions were investigated using PDAPP+/- mice in which the activity of the cytokine Tumor Necrosing Factor alpha (TNFalpha) was attenuated by chronic treatment with anti-TNF or deleting TNFalpha (TNF-/-). Two different categories of behavior were analyzed in adult (6 months) and middle aged (15 months) subjects. Classically, the cognitive performance was assessed from the escape efficacy and quantitative bias toward the training position in a Morris water maze. Second, stereotyped circling was quantified, along with more qualitative behavioral impairments such as self-mutilation or increased reactivity. Our results can be summarized as follows. (1) All of the PDAPP mice expressed reduced cognitive performance in the Morris task, but only those with a clear-cut amyloid burden in the hippocampus showed behavioral abnormalities such as stereotyped circling. (2) Chronic treatment with anti-TNF prevented the development of pathological circling in the 6-month-old mice but not in the 15-month-old mice and had no significant effect on amyloid burden. (3) The absence of TNFalpha prevented the development of stereotyped circling in 6- and 15-month-old mice but increased amyloid burden after 15 months. These data indicate that PDAPP mice express cognitive impairments disregarding absence of TNF. The pathological behavioral anomalies related to the PDAPP mutation seem reduced by treatments interfering with TNFalpha.

Cholinergic enhancement of perceptual learning : behavioral, physiological, and neuro-pharmacological study in the rat primary visual cortex

Les cortices sensoriels sont des régions cérébrales essentielles pour la perception. En particulier, le cortex visuel traite l’information visuelle en provenance de la rétine qui transite par le thalamus. Les neurones sont les unités fonctionnelles qui transforment l'information sensorielle en signaux électriques, la transfèrent vers le cortex et l'intègrent. Les neurones du cortex visuel sont spécialisés et analysent différents aspects des stimuli visuels. La force des connections entre les neurones peut être modulée par la persistance de l'activité pré-synaptique et induit une augmentation ou une diminution du signal post-synaptique à long terme. Ces modifications de la connectivité synaptique peuvent induire la réorganisation de la carte corticale, c’est à dire la représentation de ce stimulus et la puissance de son traitement cortical. Cette réorganisation est connue sous le nom de plasticité corticale. Elle est particulièrement active durant la période de développement, mais elle s’observe aussi chez l’adulte, par exemple durant l’apprentissage. Le neurotransmetteur acétylcholine (ACh) est impliqué dans de nombreuses fonctions cognitives telles que l’apprentissage ou l’attention et il est important pour la plasticité corticale. En particulier, les récepteurs nicotiniques et muscariniques du sous-type M1 et M2 sont les récepteurs cholinergiques impliqués dans l’induction de la plasticité corticale. L’objectif principal de la présente thèse est de déterminer les mécanismes de plasticité corticale induits par la stimulation du système cholinergique au niveau du télencéphale basal et de définir les effets sur l’amélioration de la perception sensorielle. Afin d’induire la plasticité corticale, j’ai jumelé des stimulations visuelles à des injections intracorticales d’agoniste cholinergique (carbachol) ou à une stimulation du télencéphale basal (neurones cholinergiques qui innervent le cortex visuel primaire). J'ai analysé les potentiels évoqués visuels (PEVs) dans le cortex visuel primaire des rats pendant 4 à 8 heures après le couplage. Afin de préciser l’action de l’ACh sur l’activité des PEVs dans V1, j’ai injecté individuellement l’antagoniste des récepteurs muscariniques, nicotiniques, α7 ou NMDA avant l’infusion de carbachol. La stimulation du système cholinergique jumelée avec une stimulation visuelle augmente l’amplitude des PEVs durant plus de 8h. Le blocage des récepteurs muscarinique, nicotinique et NMDA abolit complètement cette amélioration, tandis que l’inhibition des récepteurs α7 a induit une augmentation instantanée des PEVs. Ces résultats suggèrent que l'ACh facilite à long terme la réponse aux stimuli visuels et que cette facilitation implique les récepteurs nicotiniques, muscariniques et une interaction avec les récepteur NMDA dans le cortex visuel. Ces mécanismes sont semblables à la potentiation à long-terme, évènement physiologique lié à l’apprentissage. L’étape suivante était d’évaluer si l’effet de l’amplification cholinergique de l’entrée de l’information visuelle résultait non seulement en une modification de l’activité corticale mais aussi de la perception visuelle. J’ai donc mesuré l’amélioration de l’acuité visuelle de rats adultes éveillés exposés durant 10 minutes par jour pendant deux semaines à un stimulus visuel de type «réseau sinusoïdal» couplé à une stimulation électrique du télencéphale basal. L’acuité visuelle a été mesurée avant et après le couplage des stimulations visuelle et cholinergique à l’aide d’une tâche de discrimination visuelle. L’acuité visuelle du rat pour le stimulus d’entrainement a été augmentée après la période d’entrainement. L’augmentation de l’acuité visuelle n’a pas été observée lorsque la stimulation visuelle seule ou celle du télencéphale basal seul, ni lorsque les fibres cholinergiques ont été lésées avant la stimulation visuelle. Une augmentation à long terme de la réactivité corticale du cortex visuel primaire des neurones pyramidaux et des interneurones GABAergiques a été montrée par l’immunoréactivité au c-Fos. Ainsi, lorsque couplé à un entrainement visuel, le système cholinergique améliore les performances visuelles pour l’orientation et ce probablement par l’optimisation du processus d’attention et de plasticité corticale dans l’aire V1. Afin d’étudier les mécanismes pharmacologiques impliqués dans l’amélioration de la perception visuelle, j’ai comparé les PEVs avant et après le couplage de la stimulation visuelle/cholinergique en présence d’agonistes/antagonistes sélectifs. Les injections intracorticales des différents agents pharmacologiques pendant le couplage ont montré que les récepteurs nicotiniques et M1 muscariniques amplifient la réponse corticale tandis que les récepteurs M2 muscariniques inhibent les neurones GABAergiques induisant un effet excitateur. L’infusion d’antagoniste du GABA corrobore l’hypothèse que le système inhibiteur est essentiel pour induire la plasticité corticale. Ces résultats démontrent que l’entrainement visuel jumelé avec la stimulation cholinergique améliore la plasticité corticale et qu’elle est contrôlée par les récepteurs nicotinique et muscariniques M1 et M2. Mes résultats suggèrent que le système cholinergique est un système neuromodulateur qui peut améliorer la perception sensorielle lors d’un apprentissage perceptuel. Les mécanismes d’amélioration perceptuelle induits par l’acétylcholine sont liés aux processus d’attention, de potentialisation à long-terme et de modulation de la balance d’influx excitateur/inhibiteur. En particulier, le couplage de l’activité cholinergique avec une stimulation visuelle augmente le ratio de signal / bruit et ainsi la détection de cibles. L’augmentation de la concentration cholinergique corticale potentialise l’afférence thalamocorticale, ce qui facilite le traitement d’un nouveau stimulus et diminue la signalisation cortico-corticale minimisant ainsi la modulation latérale. Ceci est contrôlé par différents sous-types de récepteurs cholinergiques situés sur les neurones GABAergiques ou glutamatergiques des différentes couches corticales. La présente thèse montre qu’une stimulation électrique dans le télencéphale basal a un effet similaire à l’infusion d’agoniste cholinergique et qu’un couplage de stimulations visuelle et cholinergique induit la plasticité corticale. Ce jumelage répété de stimulations visuelle/cholinergique augmente la capacité de discrimination visuelle et améliore la perception. Cette amélioration est corrélée à une amplification de l’activité neuronale démontrée par immunocytochimie du c-Fos. L’immunocytochimie montre aussi une différence entre l’activité des neurones glutamatergiques et GABAergiques dans les différentes couches corticales. L’injection pharmacologique pendant la stimulation visuelle/cholinergique suggère que les récepteurs nicotiniques, muscariniques M1 peuvent amplifier la réponse excitatrice tandis que les récepteurs M2 contrôlent l’activation GABAergique. Ainsi, le système cholinergique activé au cours du processus visuel induit des mécanismes de plasticité corticale et peut ainsi améliorer la capacité perceptive. De meilleures connaissances sur ces actions ouvrent la possibilité d’accélérer la restauration des fonctions visuelles lors d’un déficit ou d’amplifier la fonction cognitive.

Effects of diethylpropion treatment and withdrawal on aorta reactivity, endothelial factors and rat behavior

Diethylpropion (DEP) is an amphetamine-like compound used as a coadjutant in the treatment of obesity and which presents toxicological importance as a drug of abuse. This drug causes important behavioral and cardiovascular complications; however, the vascular and behavioral alterations during DEP treatment and withdrawal, have not been determined. We evaluated the effects of DEP treatment and withdrawal on the rat aorta reactivity to noradrenaline, focusing on the endothelium, and the rat behavior during DEP treatment and withdrawal. DEP treatment caused a hyporreactivity to noradrenaline in aorta, reversible after 2 days of withdrawal and abolished by both the endothelium removal and the presence of L-NAME, but not by the presence of indomethacin. Furthermore, DEP treatment increased the general activity of rats. Contrarily, DEP withdrawal caused a decrease in the locomotor activity and an increase in grooming behavior, on the 2nd and 7th days after the interruption of the treatment, respectively. DEP treatment also caused an adaptive vascular response to noradrenaline that seems to be dependent on the increase in the endothelial nitric oxide system activity, but independent of prostaglandins synthesis. The data evidenced chronological differences in the adaptive responses of the vascular and central nervous systems induced by DEP treatment. Finally, a reversion of the adaptive response to DEP was observed in the vascular system during withdrawal, whereas a neuroadaptive process was still present in the central nervous system post-DEP. These findings advance on the understanding of the vascular and behavioral pathophysiological processes involved in the therapeutic and abusive uses of DEP. (C) 2003 Elsevier B.V. (USA). All rights reserved.

Does the neonatal clinical risk for illness severity influence pain reactivity and recovery in preterm infants?

Background: The biobehavioural pain reactivity and recovery of preterm infants in the neonatal period may reflect the capacity of the central nervous system to regulate neurobiological development. Objective: The aim of the present study was to analyse the influence of the neonatal clinical risk for illness severity on biobehavioural pain reactivity in preterm infants. Methods: Fifty-two preterm infants were allocated into two groups according to neonatal severity of illness, as measured by the Clinical Risk Index for Babies (CRIB). The low clinical risk (LCr) group included 30 neonates with CRIB scores <4, and the high clinical risk (HCr) group included 22 neonates with CRIB scores >= 4. Pain reactivity was assessed during a blood collection, which was divided into five phases (baseline, antisepsis, puncture, recovery-dressing and recovery-resting). Behavioral pain reactivity was measured using the scores, and magnitude of responses in Neonatal Facial Coding System (NFCS) and Sleep-Wake States Scale (SWS). The heart rate was continuously recorded. Results: The HCr demonstrated a higher magnitude of response on the SWS score from the baseline to the puncture phase than the LCr. Also, the HCr exhibited a higher mean heart rate and minimum heart rate than the LCr in the recovery-resting phase. In addition, the HCr exhibited a higher minimum heart rate from the baseline to the recovery-resting phase than the LCr. Conclusion: The infants exhibiting a high neonatal clinical risk showed high arousal during the puncture procedure and higher physiological reactivity in the recovery phase.

The future in action: neurophysiological and behavioral evidence of anticipatory motor simulation.

The motor system can no longer be considered as a mere passive executive system of motor commands generated elsewhere in the brain. On the contrary, it is deeply involved in perceptual and cognitive functions and acts as an “anticipation device”. The present thesis investigates the anticipatory motor mechanisms occurring in two particular instances: i) when processing sensory events occurring within the peripersonal space (PPS); and ii) when perceiving and predicting others’actions. The first study provides evidence that PPS representation in humans modulates neural activity within the motor system, while the second demonstrates that the motor mapping of sensory events occurring within the PPS critically relies on the activity of the premotor cortex. The third study provides direct evidence that the anticipatory motor simulation of others’ actions critically relies on the activity of the anterior node of the action observation network (AON), namely the inferior frontal cortex (IFC). The fourth study, sheds light on the pivotal role of the left IFC in predicting the future end state of observed right-hand actions. Finally, the fifth study examines how the ability to predict others’ actions could be influenced by a reduction of sensorimotor experience due to the traumatic or congenital loss of a limb. Overall, the present work provides new insights on: i) the anticipatory mechanisms of the basic reactivity of the motor system when processing sensory events occurring within the PPS, and the same anticipatory motor mechanisms when perceiving others’ implied actions; ii) the functional connectivity and plasticity of premotor-motor circuits both during the motor mapping of sensory events occurring within the PPS and when perceiving others’ actions; and iii) the anticipatory mechanisms related to others’ actions prediction.

Exercise and Mood: Exploring the Role of Exercise in Regulating Stress Reactivity in Bipolar Disorder

Bipolar Disorder (BD) is a recurrent and debilitating psychological disorder characterized by a chronic dysregulation of mood with fluctuations between extremely low (e.g., depression) and extremely elevated mood states (e.g., mania), and ranks as the 6th leading cause of disability in the world. Although research has consistently shown that exercise may have antidepressant and stress-attenuating benefits in other psychiatric illnesses (e.g., depression, anxiety), these benefits have not been directly investigated for BD. The current study represents the first known investigation to examine this relationship. Single-participant designs, with crossover and interaction treatment components (i.e., A/B/A/B/A, A/C/A/C/A, A/B/A/C/A, or A/C/A/B/A) were utilized to investigate the impact of participation in a prescribed regimen of exercise (EP) versus standard behavioral activation (SBA; i.e., non-exercise activity) has on stress perception and reactivity, and mood stability in a sample of individuals with BD. Individuals completed four total weeks of treatment, and psychophysiological measures of reactivity were recorded during a laboratory stress task (i.e., backward counting task) prior to and following each two-week intervention phase. No appreciable differences were found between levels of exercise participation between treatment groups. Interestingly, symptoms of depressed mood (BDI-II scores) decreased at similar rates following 4 weeks of treatment for all participants. BDI-II decreases were found to be most correlated with elective exercise participation, although this relationship was not significant. Regarding stress reactivity, elective participation in mild to moderate intensity exercise was found to reduce an individual’s perception of stress reactivity to an acute stressor, while participation in a prescribed program of exercise was more effective in reducing physiological response to the same task. Utilizing multiple forms of behavioral activation simultaneously was found to be most effective in decreasing perception of stress reactivity, and may also result in a positive change in the use of adaptive versus maladaptive coping strategies. Participation in a 4-week program of exercise appeared to provide the most benefit, consistent with exercise habituation theories. Overall, current findings provide preliminary support for the prophylactic benefits of including a prescribed and monitored program of exercise as an adjunct treatment for individuals with BD. Larger scale research is needed to more clearly determine the impact of exercise on stress reactivity and mood episode relapse in individuals with BD.