Papers by Snezana Urosevic
Journal of Affective Disorders, 2016
Objectives-Bipolar disorders' (BD) onset before age 18 is a potential marker for a more severe il... more Objectives-Bipolar disorders' (BD) onset before age 18 is a potential marker for a more severe illness course. Adolescence is also a period of significant normative maturation of inhibitory control and reward-relevant decision-making processes, such as decreased delay discounting (i.e., decreased preference for smaller, immediate versus larger, delayed rewards). Adults with BD exhibit elevated delay discounting rates. Very little is known about developmental changes in delay discounting in adolescents with BD, or about associations between inhibitory control and delay discounting in BD. The present study addresses these questions. Methods-The sample included 78 participants, ages 13 to 23, with BD or without history of mental illness. Group differences and group by age interaction effects on delay discounting (32 BD, 32 controls with valid responses), probability discounting (34 BD, 37 controls) and inhibitory control indices (34 BD, 38 controls) were assessed. Results-Among healthy controls, less discounting of delayed rewards was associated with older age, whereas adolescents with BD did not show age-related associations. There were no group differences in probability discounting or inhibitory control. Limitations-The cross-sectional nature of the study cannot fully rule out the less likely interpretation of group differences in cohort effects. Conclusions-The lack of age-related improvement in delay tolerance in BD suggests disrupted development of executive control processes within reward contexts, which in turn may contribute to understanding more severe course of pediatric onset BD. Longitudinal studies are needed to examine delay discounting in relation to maturation of neural reward systems among adolescents with BD.
Journal of Affective Disorders, 2018
Background: Little is known about the specificity of executive functioning (EF) decline in older ... more Background: Little is known about the specificity of executive functioning (EF) decline in older adults with bipolar disorders (OABD), or the impact of bipolar disorders (BD) on the timing and slope of age-related declines in EF processes implicated in both BD etiology and normative aging-cognitive control (CC). This cross-sectional study investigated age-related CC decline in BD. Methods: Participants were 43 adults with BD (M age = 61.5, SD = 15.8; 86% male) and 45 Controls (M age = 65.2, SD = 12.2; 98% male). Two-way ANOVAs examined the effects of median-age-split and diagnostic groups on cognitive processes with established BD deficits-CC processes (mental flexibility and response inhibition), verbal learning, and verbal fluency. Results: The median-split-age-by-diagnostic-group interaction was significant for mental flexibility; OABD performed significantly worse than younger adults with BD and younger and older Controls. Exploratory multivariate adaptive regression spline characterized non-linear nature of aging-slope changes in mental flexibility for each diagnostic group, yielding an inflection point at older age and steeper subsequent decline in OABD versus Controls. Limitations: This study is limited by a small sample (particularly for select neuropsychological measures) of mostly Caucasian men and BD diagnoses based on clinical interview and medical records review. Conclusions: Compared to healthy older adults, OABD showed steeper age-related decline in mental flexibility-select EF processes that depend on the integrity of the CC system. Preliminary evidence links CC integrity to daily functioning in OABD; accelerated aging decline in CC may pose a mechanism for high risk of functional impairment and dementia in OABD. 2015; Wu et al., 2013). Thus, understanding the mechanisms that lead
Cognitive, Affective, & Behavioral Neuroscience, May 16, 2019
Hypersensitivity to reward-relevant stimuli is theorized to be a core etiological factor in bipol... more Hypersensitivity to reward-relevant stimuli is theorized to be a core etiological factor in bipolar disorders (BDs). However, little is known about the role of cognitive control dysregulation within reward contexts in BDs, particularly during adolescence. Using electroencephalography (EEG), we explored alterations in cognitive control processes and approach motivation in 99 adolescents with (n=53) and without (n=46) BD during reward striving (target anticipation) and reward attainment (feedback) phases of a monetary incentive delay (MID) task. Time-frequency analysis yielded frontal theta and frontal alpha asymmetry as indices of cognitive control and approach motivation, respectively. Multilevel mixed models examined group differences, as well as age, sex, and other effects, on frontal theta and frontal alpha asymmetry during both phases of the task and on performance accuracy and reaction times. Healthy adolescent girls exhibited lower frontal theta than both adolescent girls with BD and adolescent boys with and without BD during reward anticipation and feedback. Across groups, adolescent boys displayed greater relative left frontal alpha activity than adolescent girls during reward anticipation and feedback. Behaviorally, adolescents with BD exhibited faster responses on both positively and negatively motivated trials versus neutral trials, whereas healthy adolescents had faster responses only on positively motivated trials; adolescents with BD were less accurate in responding to neutral trials compared to healthy controls. These findings shed light on normative and BD-specific involvement of approach motivation and cognitive control during different stages of reward processing in adolescence and, further, provide evidence of adolescent sex differences in these processes.
Journal of clinical and experimental neuropsychology, Jan 23, 2017
Adolescent cannabis use (CU) is associated with impaired attention, executive function, and verba... more Adolescent cannabis use (CU) is associated with impaired attention, executive function, and verbal learning/memory. These associations are generally observed in cross-sectional studies. Longitudinal studies of cannabis users are lacking. The present study examines associations between CU and cognition over time in chronic daily adolescent-onset CUs, as compared to nonusing controls. Both groups completed a neuropsychological battery at study intake and again 2 years later. Baseline group differences have been published and indicated deficits in verbal learning and memory, motivated decision-making, planning, and working memory in CUs. In this follow-up report, the longitudinal performance of users is compared to that of sustained nonusers using the same battery. At follow-up, the majority of CUs continued to report regular and heavy cannabis use. Relative impairments in the domains of working memory, planning and verbal memory remained stable, suggesting that these are enduring vuln...
Journal of abnormal psychology, 2017
Although personality disorders (PDs) are highly comorbid with bipolar spectrum disorders (BSDs), ... more Although personality disorders (PDs) are highly comorbid with bipolar spectrum disorders (BSDs), little longitudinal research has been conducted to examine the prospective impact of PD symptoms on the course of BSDs. The aim of this study is to examine whether PD symptom severity predicts shorter time to onset of bipolar mood episodes and conversion to bipolar I disorder over time among individuals with less severe BSDs. Participants (n = 166) with bipolar II disorder, cyclothymia, or bipolar disorder not otherwise specified completed diagnostic interview assessments of PD symptoms and self-report measures of mood symptoms at baseline. They were followed prospectively with diagnostic interviews every 4 months for an average of 3.02 years. Cox proportional hazard regression analyses indicated that overall PD symptom severity significantly predicted shorter time to onset of hypomanic (hazard ratio [HR] = 1.42; p < .001) and major depressive episodes (HR = 1.51; p < .001) and con...
Journal of clinical …, 2010
The extent to which stress generation occurs in bipolar spectrum disorders (BSD) is not well unde... more The extent to which stress generation occurs in bipolar spectrum disorders (BSD) is not well understood. The present study examined whether 75 BSD participants experienced elevated rates of behavior-dependent life events, as compared with 88 normal control participants. Within the BSD group, we also examined whether depressive or hypomanic symptoms prospectively predicted increases in various types of negative and positive life events. Results indicated that BSD participants experienced overall increases in behavior-dependent events over the follow-up, as compared with normal controls. At the symptom level, the event generation process occurred in more specific event domains. Results suggest that the stress generation theory of unipolar depression can be extended to BSD and that the type of generated events may be polarity-specific.
NeuroImage: Clinical, 2016
Reward/behavioral approach system hypersensitivity is implicated in bipolar disorders (BD) and in... more Reward/behavioral approach system hypersensitivity is implicated in bipolar disorders (BD) and in normative development during adolescence. Pediatric onset of BD is associated with a more severe illness course. However, little is known about neural processing of rewards in adolescents with BD or developmental (i.e., age) associations with activation of these neural systems. The present study aims to address this knowledge gap. The present sample included 21 adolescents with BD and 26 healthy adolescents, ages 13 to 19. Participants completed a functional magnetic resonance imaging (fMRI) protocol using the Monetary Incentive Delay (MID) task. Behavioral performance was similar between groups. Group differences in BOLD activation during target anticipation and feedback anticipation periods of the task were examined using whole-brain analyses, as were group differences in age effects. During both target anticipation and feedback anticipation, adolescents with BD, compared to adolescents without psychopathology, exhibited decreased engagement of frontal regions involved in cognitive control (i.e., dorsolateral prefrontal cortex). Healthy adolescents exhibited age-related decreases, while adolescents with BD exhibited age-related increases, in activity of other cognitive control frontal areas (i.e., right inferior frontal gyrus), suggesting altered development in the BD group. Longitudinal research is needed to examine potentially abnormal development of cognitive control during reward pursuit in adolescent BD and whether early therapeutic interventions can prevent these potential deviations from normative development.
Social cognitive and affective neuroscience, 2015
This longitudinal study examines associations between baseline individual differences and develop... more This longitudinal study examines associations between baseline individual differences and developmental changes in reward [i.e. behavioral approach system (BAS)] sensitivity and relevant brain structures' volumes to prospective substance use initiation during adolescence. A community sample of adolescents ages 15-18 with no prior substance use was assessed for substance use initiation (i.e. initiation of regular alcohol use and/or any use of other substances) during a 2-year follow-up period and for alcohol use frequency in the last year of the follow-up. Longitudinal 'increases' in BAS sensitivity were associated with substance use initiation and increased alcohol use frequency during the follow-up. Moreover, adolescents with smaller left nucleus accumbens at baseline were more likely to initiate substance use during the follow-up period. This study provides support for the link between developmental increases in reward sensitivity and substance use initiation in adoles...
Motivation and Emotion, 2006
In this article, we tested the vulnerability hypothesis of the behavioral approach system (BAS) h... more In this article, we tested the vulnerability hypothesis of the behavioral approach system (BAS) hypersensitivity model of bipolar disorders. We examined whether selfreported BAS sensitivity predicts lifetime bipolar spectrum diagnoses as well as symptoms and personality characteristics associated with bipolar disorder using a retrospective and concurrent behavioral high-risk design. Participants with high (HBAS; n = 28) or moderate (MBAS; n = 24) BAS sensitivity were selected and given a lifetime psychiatric diagnostic interview and self-report measures of proneness to bipolar symptoms, current symptoms, and personality characteristics relevant to bipolarity. HBAS participants were significantly and substantially more likely to have a lifetime bipolar spectrum disorder diagnosis than were MBAS participants, but did not differ from MBAS participants in their likelihood of a unipolar depression diagnosis. Also, the HBAS group exhibited higher impulsivity and proneness to hypomanic symptoms than the MBAS group, and BAS-reward responsiveness predicted hypomanic personality characteristics. Finally, high behavioral inhibition system (BIS) sensitivity was associated with proneness to and current depressive symptoms.
Journal of Abnormal Psychology, 2012
Bipolar disorder is characterized by a hypersensitivity to reward-relevant cues and a propensity ... more Bipolar disorder is characterized by a hypersensitivity to reward-relevant cues and a propensity to experience an excessive increase in approach-related affect, which may be reflected in hypo/manic symptoms. The present study examined the relationship between relative left-frontal electroencephalographic (EEG) activity, a proposed neurophysiological index of approach-system sensitivity and approach/reward-related affect, and bipolar course and state-related variables. Fifty-eight individuals with cyclothymia or bipolar II disorder and 59 healthy control participants with no affective psychopathology completed resting EEG recordings. Alpha power was obtained and asymmetry indices computed for homologous electrodes. Bipolar spectrum participants were classified as being in a major/minor depressive episode, a hypomanic episode, or a euthymic/remitted state at EEG recording. Participants were then followed prospectively for an average 4.7-year follow-up period with diagnostic interview assessments every 4 months. Sixteen bipolar spectrum participants converted to bipolar I disorder during follow-up. Consistent with hypotheses, elevated relative left-frontal EEG activity at baseline (a) prospectively predicted a greater likelihood of converting from cyclothymia or bipolar II disorder to bipolar I disorder over the 4.7-year follow-up period, (b) was associated with an earlier age-of-onset of first bipolar spectrum episode, and (c) was significantly elevated in bipolar spectrum individuals in a hypomanic episode at EEG recording. This is the first study to our knowledge to identify a neurophysiological marker that prospectively predicts conversion to bipolar I disorder. The fact that unipolar depression is characterized by decreased relative left-frontal EEG activity suggests that unipolar depression and vulnerability to hypo/mania may be characterized by different profiles of frontal EEG asymmetry.
Journal of Abnormal Psychology, 2010
Research indicates that life events involving goal attainment and goal striving trigger hypomania... more Research indicates that life events involving goal attainment and goal striving trigger hypomania/mania and that negative life events trigger bipolar depression. These findings are consistent with the behavioral approach system (BAS) dysregulation model of bipolar disorders, which suggests that individuals with bipolar disorders are hypersensitive to cues signaling opportunity for reward and cues signaling failure and loss of rewards. However, no studies to date have investigated whether individuals with bipolar spectrum disorders experience increased rates of these BAS-relevant life events, which would place them at double risk for developing bipolar episodes. The present study found that individuals with bipolar II disorder and cyclothymia experience increased rates of BAS-activating and BAS-deactivating, but not goal-attainment, life events. Finally, for bipolar spectrum individuals only, BAS-activating events predicted BAS-deactivating events' rates.
Developmental Psychology, 2012
Figure 2 was distorted in production. The correct version is presented in the erratum.] Adolescen... more Figure 2 was distorted in production. The correct version is presented in the erratum.] Adolescence is a period of radical normative changes and increased risk for substance use, mood disorders, and physical injury. Researchers have proposed that increases in reward sensitivity (i.e., sensitivity of the behavioral approach system [BAS]) and/or increases in reactivity to all emotional stimuli (i.e., reward and threat sensitivities) lead to these phenomena. The present study is the first longitudinal investigation of changes in reward (i.e., BAS) sensitivity in 9- to 23-year-olds across a 2-year follow-up. Support was found for increased reward sensitivity from early to late adolescence, and evidence was found for decline in the early 20s. This decline is combined with a decrease in left nucleus accumbens (Nacc) volume, a key structure for reward processing, from the late teens into the early 20s. Furthermore, we found longitudinal increases in sensitivity to reward to be predicted by individual differences in the Nacc and medial orbitofrontal cortex (OFC) volumes at baseline in this developmental sample. Similarly, increases in sensitivity to threat (i.e., behavioral inhibition system sensitivity) were qualified by sex, with only females participants experiencing this increase, and predicted by individual differences in lateral OFC volumes at baseline.
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Papers by Snezana Urosevic