Shared and Disorder-Specific Event-Related Brain Oscillatory Markers of Attentional Dysfunction in ADHD and Bipolar Disorder

Abstract

Attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder (BD) often present with overlapping symptoms and cognitive impairments, such as increased fluctuations in attentional performance measured by increased reaction-time variability (RTV). We previously provided initial evidence of shared and distinct event-related potential (ERP) impairments in ADHD and BD in a direct electrophysiological comparison, but no study to date has compared neural mechanisms underlying attentional impairments with finer-grained brain oscillatory markers. Here, we aimed to compare the neural underpinnings of impaired attentional processes in ADHD and BD, by examining event-related brain oscillations during a reaction-time task under slow-unrewarded baseline and fast-incentive conditions. We measured cognitive performance, ERPs and brain-oscillatory modulations of power and phase variability in 20 women with ADHD, 20 women with BD (currently euthymic) and 20 control women. Compared to controls, both ADHD and BD groups showed increased RTV in the baseline condition and increased RTV, theta phase variability and lower contingent negative variation in the fast-incentive condition. Unlike controls, neither clinical group showed an improvement from the slow-unrewarded baseline to the fast-incentive condition in attentional P3 amplitude or alpha power suppression. Most impairments did not differ between the disorders, as only an adjustment in beta suppression between conditions (lower in the ADHD group) distinguished between the clinical groups. These findings suggest shared impairments in women with ADHD and BD in cognitive and neural variability, preparatory activity and inability to adjust attention allocation and activation. These overlapping impairments may represent shared neurobiological mechanisms of attentional dysfunction in ADHD and BD, and potentially underlie common symptoms in both disorders.Electronic supplementary materialThe online version of this article (10.1007/s10548-018-0625-z) contains supplementary material, which is available to authorized users.

Context Regulation of Mind Wandering in ADHD

“…In contrast, working memory might reflect an additive impairment to ADHD, which does not play such a direct causal role in the maintenance of MW and ADHD symptoms. This view is supported by previous findings showing that sustained attention/vigilance measures show a stronger overlap in familial/genetic influences with ADHD than higher-level executive functions such as working memory (Kuntsi et al, 2010(Kuntsi et al, , 2014Michelini, Kitsune, et al, 2018). Measures associated with sustained attention/vigilance also track the ADHD developmental course since they were found to be impaired in adolescents and adults with ADHD that persisted from childhood but not in remitted cases; whereas working memory and other measures of higher-level executive functions did not distinguish between ADHD persisters and remitters (Cheung et al, 2016;Michelini et al, 2016).…”

Beneficial effects of acute high-intensity exercise on electrophysiological indices of attention processes in young adult men

“…In the Fast Task, baseline correction was performed using 200-ms pre-stimulus reference period, in line with other studies using this task [ 37 , 55 ]. P3 amplitude was analysed as the maximum amplitude at Pz between 250 and 500 ms following the target.…”

“…P3 amplitude was analysed as the maximum amplitude at Pz between 250 and 500 ms following the target. The electrode and latency window used were selected based on previous work from our group [ 37 , 55 ], topographic maps and the grand averages.…”

Electrophysiological correlates of spontaneous mind wandering in attention-deficit/hyperactivity disorder

“…Using q EEG analyses, posterior alpha power, thought to reflect attentional selection and activation (also commonly referred to as attention inhibition/gating [ 31 ]), was increased in individuals with ADHD compared to controls during a sustained attention task [ 32 ], and showed a familial association with the disorder [ 33 ]. More detailed time-frequency analyses further reported attenuated event-related alpha suppression in individuals with ADHD, show attenuated event-related alpha suppression, under high cognitive demands [ 34 ] and during attentional performance [ [35] , [36] , [37] ]. Attenuated alpha suppression during visual attention tasks has also been linked to task performance, including increased RTV and omission errors, in individuals with ADHD [ 38 ], as well as failure to suppress activity in task-irrelevant (sensorimotor) regions [ 39 ].…”

“…Attenuated alpha suppression during visual attention tasks has also been linked to task performance, including increased RTV and omission errors, in individuals with ADHD [ 38 ], as well as failure to suppress activity in task-irrelevant (sensorimotor) regions [ 39 ]. Further initial evidence in individuals with ADHD indicates reduced event-related theta power (reflecting reduced attention allocation) and increased theta phase variability (neural variability in stimulus processing over trials) during an attentional task [ 37 , 40 ], which were also associated with greater RTV [ 40 ]. Reduced event-related beta suppression, thought to be a marker of motor response activity, has also been reported in adults with ADHD during an attentional task [ 35 ].…”