Hyperactivity and sensation seeking as autoregulatory attempts to stabilize brain arousal in ADHD and mania?

Abstract

Hypoarousal as indicated by skin conductance and electroencephalography (EEG) has been discussed as a pathogenetic factor in attention-deficit/hyperactivity disorder (ADHD). The aim of this paper was to review these arousal-related pathogenetic concepts and to present the more recently proposed vigilance regulation model of affective disorders and ADHD. The latter builds on methodological advances in classifying short EEG segments into vigilance stages (Vigilance Algorithm Leipzig, VIGALL), indicating different states of global brain function ("brain arousal"). VIGALL allows the objective assessment of vigilance regulation under defined conditions, e.g. how fast vigilance declines to lower vigilance stages associated with drowsiness during 15-20-min EEG recordings under resting conditions with eyes closed. According to the vigilance regulation model, the hyperactivity and sensation seeking observed in overtired children, ADHD and mania may be interpreted as an autoregulatory attempt to create a stimulating environment in order to stabilize vigilance. The unstable regulation of vigilance observed in both mania and ADHD may thus explain the attention deficits, which become especially prominent in monotonous sustained attention tasks. Among the arguments supporting the vigilance regulation model are the facts that destabilizing vigilance (e.g., via sleep deprivation) can trigger or exacerbate symptoms of ADHD or mania, whereas stabilizing vigilance (e.g., via psychostimulants, reducing sleep deficits) alleviates these symptoms. The potential antimanic effects of methylphenidate are presently being studied in an international randomized controlled trial. We propose vigilance regulation as a converging biomarker, which could be useful for identifying treatment responders to psychostimulants and forming pathophysiologically more homogeneous ADHD subgroups for research purposes.

Listening to the Patient Voice in Narcolepsy: Diagnostic Delay, Disease Burden, and Treatment Efficacy

“…Notably, symptoms of narcolepsy may present differently among children. Excessive daytime sleepiness in children can manifest as attentional problems, externalizing behaviors (such as hyperactivity), and/or emotional lability, 24,25 leading to possible misdiagnosis of primary attention deficit hyperactivity disorder or other psychopathology. Children with narcolepsy type 1 can also present with atypical cataplexy with static appearance of hypotonia, ptosis, and/or jaw slackening and dyskinetic movements 7 that may be mistaken for other neurological disorders.…”

Assessment of Wakefulness and Brain Arousal Regulation in Psychiatric Research

“…Concerning ADHD, lines of evidence are similar: studies applying skin conductance level, MSLT, MWT, quantitative EEG, VIGALL and Epworth Sleepiness Scale demonstrated that many ADHD patients are characterized by an unstable arousal regulation [66,[115][116][117][118] . Thus, the rapid therapeutic effects of stimulants in ADHD could be explained by their arousal-stabilizing properties.…”

“…In contrast, mania was characterized by rapid EEG vigilance decline under resting conditions in former EEG case reports [58,62,63] , which was replicated in a more recent case report applying VIGALL [64] . In attention-deficit/hy- peractivity disorder (ADHD), which shows overlap with mania not only on the symptom level [65] , an unstable arousal regulation has long been suggested as a pathogenetic factor [66] . Using VIGALL, further evidence for unstable arousal in ADHD has been given [67] .…”

Inferior frontal cortex activity is modulated by reward sensitivity and performance variability

“…Another potential intervening factor that could be explored in future studies is arousal regulation since poor or variable performance in long and monotonous tasks in ADHD patients has been linked to poor arousal regulation (Geissler et al, 2014;Karalunas et al, 2014).…”