Information processing in adolescents with bipolar I disorder

Longitudinal analysis of cognitive performances in recent-onset and late-life Bipolar Disorder: A systematic review and meta-analysis

OBJECTIVES

Neurocognitive deficits have been widely reported in euthymic Bipolar Disorder (BD) patients and contribute to functional disability. However, the longitudinal trajectory of these deficits remains a subject of debate. Although most research to this date shows that neurocognitive deficits tend to be stable among middle-age BD patients, it remains plausible that deterioration occurs at either early or late stages of this condition.

METHODS

We conducted a comprehensive meta-analysis of studies that reported longitudinal neurocognitive performance among individuals with BD either within the year of their diagnosis or among late-life BD patients. Pooled effects of standardized mean differences (SMDs) for changes in neuropsychological scores over follow-up were estimated using random effects model. We also examined effect moderators, such as length of follow-up, mood state, or pharmacological load.

RESULTS

Eight studies met inclusion criteria for recent-onset and four studies for late-life BD analysis. No evidence for a deterioration in neurocognitive functioning was observed among recent-onset BD patients (8 studies, 284 patients, SMD: 0.12, 95% CI -0.06 to 0.30, mean follow-up: 17 months) nor for late-life BD patients (4 studies, 153 patients, SMD: -0.35, 95% CI -0.84 to 0.15, mean follow-up: 33 months). None of the moderators were shown to be significant.

CONCLUSIONS

These results, when appraised together with the findings in middle-life BD patients and individuals at genetic risk for BD, suggest that neurodevelopmental factors might play a significant role in cognitive deficits in BD and do not support the notion of progressive cognitive decline in most patients with BD.

Longitudinal cognitive trajectories and associated clinical variables in youth with bipolar disorder

OBJECTIVE

There is substantial interest in delineating the course of cognitive functioning in bipolar (BP) youth. However, there are no longitudinal studies aimed at defining subgroups of BP youth based on their distinctive cognitive trajectories and their associated clinical variables.

METHOD

Cognitive functioning was measured in 135 participants from the Course and Outcome of BP Youth (COBY) study using several subtests of the Cambridge Neuropsychological Test Automated Battery (CANTAB). Youth were prospectively evaluated three times on average every 13.75 months over 2.5 years. Clinical and functional outcomes were assessed using the Longitudinal Interval Follow-Up Evaluation (LIFE).

RESULTS

Latent class growth analysis identified three longitudinal patterns of cognitive functioning based on a general cognitive index: class 1, "persistently high" (N=21; 15.6%); class 2, "persistently moderate" (N=82; 60.74%); and class 3, "persistently low" (N=32; 23.7%). All classes showed normal cognitive functioning when compared with the CANTAB normative data. After adjustment for confounders, youth from class 3 had a significantly greater percentage of time with overall, manic, and depressive syndromal symptoms than youth in the other two classes. Also, after adjustment for confounders, youth from class 3 had significantly poorer global, academic, and social functioning than youth from class 1.

CONCLUSIONS

BP youth showed normal overall cognitive functioning that remained stable during the follow-up within each class. However, 24% of BP youth showed poorer cognitive functioning than the other BP youth. This subgroup had poorer mood course and functioning, and may benefit from cognitive remediation and early management with evidence-based pharmacological treatments.

Low compliance to pharmacological treatment is linked to cognitive impairment in euthymic phase of bipolar disorder

BACKGROUND

Cognitive impairment and low compliance to pharmacological treatment are frequent complications in bipolar disorder. Moreover, low compliance in patients with bipolar disorder is one of the main reasons for relapse. This in turn, is associated with an increase in neurocognitive symptoms. The current study aimed to determine whether attention, memory, and executive function are related to the level of compliance to pharmacological treatment in individuals with bipolar disorder in euthymic phase.

METHOD

We examined 34 patients with bipolar disorder (12 with low compliance to the treatment and 22 with high compliance to the treatment) according to the DSM-IV criteria, in the range of 18-55 years. All patients were assessed through a neuropsychological battery in one single session. Analysis of covariance (ANCOVA) was used to compare neuropsychological test scores between low and high compliance patients. Clinical and sociodemographic characteristics were included as covariates in the study.

RESULTS

Patients with low level of compliance performed significantly worse than high treatment compliance on verbal memory immediate free recall (F (1)=12.14, p=.002), verbal memory immediate cued recall (F (1)=10.45, p=.003), verbal memory delayed free recall (F (1)=5.52, p=.027), and verbal memory delayed cued recall (F (1)=6.11, p=.021). Covariates such as number of manic episodes, history of psychosis and years of education were found significant for executive functions and processing speed.

CONCLUSION

We found that low compliance to pharmacological treatment is consistently linked to immediate and delayed verbal memory. In addition, executive function and processing speed were associated with clinical and demographic characteristics. Limitations of this study include the small sample size, a cross-sectional design that cannot address causality, and inability to account for pharmacologic effects.

Self-images in the present and future: Role of affect and the bipolar phenotype

BACKGROUND

Bipolar Spectrum Disorder (BPSD) is associated with changes in self-related processing and affect, yet the relationship between self-image and affect in the BPSD phenotype is unclear.

METHODS

47 young adults were assessed for hypomanic experiences (BPSD phenotype) using the Mood Disorders Questionnaire. Current and future self-images (e.g. I am… I will be…) were generated and rated for emotional valence, stability, and (for future self-images only) certainty. The relationship between self-image ratings and measures of affect (depression, anxiety and mania) were analysed in relation to the BPSD phenotype.

RESULTS

The presence of the BPSD phenotype significantly moderated the relationship between (1) affect and stability ratings for negative self-images, and (2) affect and certainty ratings for positive future self-images. Higher positivity ratings for current self-images were associated with lower depression and anxiety scores.

LIMITATIONS

This was a non-clinical group of young adults sampled for hypomanic experiences, which limits the extension of the work to clinical levels of psychopathology. This study cannot address the causal relationships between affect, self-images, and BPSD. Future work should use clinical samples and experimental mood manipulation designs.

CONCLUSIONS

BPSD phenotype can shape the relationship between affect and current and future self-images. This finding will guide future clinical research to elucidate BPSD vulnerability mechanisms and, consequently, the development of early interventions.

Memory cueing during sleep modifies the interpretation of ambiguous scenes in adolescents and adults

The individual tendency to interpret ambiguous situations negatively is associated with mental disorders. Interpretation biases are already evident during adolescence and due to the greater plasticity of the developing brain it may be easier to change biases during this time. We investigated in healthy adolescents and adults whether stabilizing memories of positive or negative scenes modulates the later interpretation of similar scenes. In the evening, participants learnt associations between ambiguous pictures and words that disambiguate the valence of the pictures in a positive or negative direction. Half of the words were acoustically presented (i.e. cued) during post-learning sleep which is known to benefit memory consolidation by inducing reactivation of learned information. Cued compared to un-cued stimuli were remembered better the next morning. Importantly, cueing positively disambiguated pictures resulted in more positive interpretations whereas cueing negatively disambiguated pictures led to less positive interpretations of new ambiguous pictures with similar contents the next morning. These effects were not modulated by participants' age indicating that memory cueing was as efficient in adolescents as in adults. Our findings suggest that memory cueing during sleep can modify interpretation biases by benefitting memory stabilization and generalization. Implications for clinical settings are discussed.

Affective processing bias in youth with primary bipolar disorder or primary attention-deficit/hyperactivity disorder

High rates of comorbidity and overlapping diagnostic criteria between pediatric bipolar disorder (BD) and attention-deficit/hyperactivity disorder (ADHD) contribute to diagnostic and treatment confusion. To advance what is known about both disorders, we compared effect of emotional stimuli on response control in children with primary BD, primary ADHD and typically developing controls (TDC). Participants included 7-17 year olds with either "narrow-phenotype" pediatric BD (n = 25), ADHD (n = 25) or TDC (n = 25). Groups were matched on participant age and FSIQ. The effect of emotional stimuli on response control was assessed using the Cambridge Neuropsychological Test Automated Battery Affective Go/No-Go task (CANTAB AGN). We found a group by target valence interaction on commission errors [F(2,71) = 5.34, p < 0.01, ƞ p (2) = 0.13] whereby ADHD, but not TDC participants, made more errors on negative than positive words [t(24) = -2.58, p < 0.05, r = 0.47]. In contrast, there was a nonsignificant trend for BD participants to make fewer errors on negative versus positive words compared to ADHD and TDC participants. Between-subjects effects showed that ADHD participants made more errors than TDC, but not BD participants. Our main finding advances what is known about the effect of emotional stimuli on response control in children with ADHD. Our results suggesting a positive affective processing bias in children with ADHD compliment emerging literature show that difficulties with emotional processing and regulation may be core features of ADHD. Further, given the observed pattern of results in children with ADHD compared to BD children, our behavioral results suggest the importance of examining differences in the brain-behavior mechanisms involved in affective processing in children with ADHD compared to BD children.

Intrinsic Amygdala Functional Connectivity in Youth With Bipolar I Disorder

OBJECTIVE

Bipolar disorder (BD) commonly begins during adolescence and may continue into adulthood. Studies in adults with BD suggest that disruptions in amygdalar neural circuitry explain the pathophysiology underlying the disorder. Importantly, however, amygdala subregion networks have not yet been examined in youth close to mania onset. The goal of this study was to compare resting state functional connectivity patterns in amygdala subregions in youth with bipolar I disorder with patterns in healthy controls.

METHOD

Centromedial, laterobasal, and superficial amygdala subdivisions were assessed during rest and examined in relation to clinical measures of mania in youth (14-20 years old) with bipolar I disorder who experienced only a single episode of mania (BD; n = 20) and age-matched healthy comparison youth without any personal or family history of DSM-IV Axis I disorders (HC; n = 23).

RESULTS

Relative to HC youth, youth with BD exhibited decreased connectivity between the laterobasal subdivision of the amygdala and the hippocampus and precentral gyrus, and increased connectivity between the laterobasal subdivision and the precuneus. Connectivity between the right laterobasal amygdala and right hippocampus was positively correlated with levels of anxiety in BD but not in HC youth, and connectivity between the right laterobasal amygdala and right precuneus was negatively correlated with insight about bipolar illness.

CONCLUSION

Youth with BD have abnormal amygdala resting state network connections to regions that are critical for emotional processing and self-awareness. Longitudinal studies are needed to determine whether these aberrant patterns in youth with BD can be altered with intervention and can influence the course of disorder.

Attentional bias in euthymic bipolar I disorder

Little is known about the nature of the relation between information-processing biases and affective traits in bipolar disorder. The present study was designed to investigate whether attentional biases are evident in persons diagnosed with bipolar disorder when they are in a positive mood state, and whether biases are related to indices of emotion regulation and to prior history of mood episodes. Ninety adults diagnosed with bipolar I disorder and 81 controls with no lifetime mood disorder underwent a positive mood induction and then completed an emotion face dot-probe task; participants in the bipolar disorder group also completed a self-report measure of responses to positive affect. Attentional bias was not related to a diagnosis of bipolar disorder or to symptom severity. Consistent with hypotheses, analyses within the bipolar group indicated that greater dampening of positive affect related to significantly less attention paid to the positively valenced faces. Discussion focuses on the potential role of affective traits in shaping attentional bias in bipolar disorder.

Neurocognitive impairments among youth with pediatric bipolar disorder: a systematic review of neuropsychological research

BACKGROUND

Pediatric bipolar disorder (PBD) has emerged as a field of research in which neuropsychological studies are continuously providing new empirical findings. Despite this, a comprehensive framework for neurocognitive impairments is still lacking, and most of the evidence remains unconnected. We addressed this question through a systematic review of neuropsychological research, with the aim of elucidating the main issues concerning this topic.

METHOD

A comprehensive search of databases (PubMed, PsycINFO) was performed. Published manuscripts between 1990 and January 2014 were identified. Overall, 124 studies fulfilled inclusion criteria. Methodological differences between studies required a descriptive review of findings.

RESULTS

Evidence indicates that verbal/visual-spatial memory, processing speed, working memory, and social cognition are neurocognitive domains impaired in PBD youth. Furthermore, these deficits are greater among those who suffer acute affective symptoms, PBD type I, and/or attention deficit hyperactivity disorder (ADHD) comorbidity. In addition, several neurocognitive deficits imply certain changes in prefrontal cortex activity and are somewhat associated with psychosocial and academic disabilities. Strikingly, these deficits are consistently similar to those encountered in ADHD as well as severe mood dysregulation (SMD). Besides, some neurocognitive impairments appear before the onset of the illness and tend to maintain stable across adolescence. Finally, any therapy has not yet demonstrated to be effective on diminishing these neurocognitive impairments.

LIMITATIONS

More prolonged follow-up studies aimed at delineating the course of treatment and the response to it are warranted.

CONCLUSIONS

Despite noteworthy research on the neurocognitive profile of PBD, our knowledge is still lagging behind evidence from adult counterparts.