In dieser Studie führten 37 adulte Patienten mit einer Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS) ein Delay Discounting (DD) - Paradigma aus, während gleichzeitig mittels Funktioneller-Nahinfrarotspektroskopie (fNIRS) die Gehirnaktivität der „Regions of Interest“ (ROIs) des Orbitofrontalen-Kortex (OFC) und des Dorsolateralen-Präfrontalen-Kortex (dlPFC) gemessen wurde. Mittels Fragebögen und eines Delay Discounting Tasks (DDT) wurden zusätzlich Verhaltensparameter erhoben und flossen in den Auswertungsprozess mit ein. Vorausgegangene Untersuchungen weisen auf ein hypofunktionel-les dopaminerges System bei ADHS-Patienten hin, welches mit der ADHS-Pathogenese in Zusammenhang gebracht wird. Vor allem im Präfrontalen-Kortex (PFC), bestehend unter anderem aus OFC und dlPFC, erfolgt die Metabolisierung von Dopamin durch die Catechol-O-Methyltransferase (COMT). Hierbei hängt die Metabolisierungsgeschwindigkeit vom genetischen COMT-Val158Met- Polymorphismus ab. Die Einflussnahme dieses COMT-Val158Met-Polymorphismus auf die kortikale Aktivität der ROIs und Impulsivität ist ebenfalls Gegenstand dieser Dissertation („Imaging Genetics“). Adulte ADHS Patienten zeigten eine verstärkte Aktivität des OFC der Entscheidungskategorie „verzögert“ im Verhältnis zu der Entscheidungskategorie „sofort“. Die gemessene Impulsivität korrelierte mit der kortikalen Gehirnaktivität „DD-Kontrast“. Es konnte kein Zusammenhang zwischen Verhaltensparameter und Gehirnaktivität mit dem COMT-Polymorphismus gezeigt werden. Die erhöhte Aktivität des OFC bei der Entscheidungskategorie verzögert unterstützt die These der „Delay Aversion“ des „Dual Pathway Model“. Eine enge Konnektivität der stark dopaminerg innervierten kortiko-striataler Strukturen in Form des OFC und der Amygdala, welche Einfluss auf die ADHS-Pathogenese nehmen, erscheint somit plausibel. / In this study 37 adult subjects with ADHD (Attention Deficit Hyperactivity Disorder) performed a validated Delay Discounting (DD) paradigm. By using near-infrared-spectroskopy (NIRS) functional brain activation in the regions of interest (ROIs) was measured. The ROIs are represented by the Orbito-Frontal-Cortex (OFC) and the Dorsolateral Prefrontal Cortex (dlPFC). Additionally questionnaires with relation to behaviour and a Delay Discounting Task (DDT) were interpreted. Former studies indicate a hypo-functional dopaminergic system in ADHD pathology. Mainly the Prefrontal Cortex (PFC), including the OFC and the dlPFC, metabolizes dopamine with the Catechol-O-Methyltransferase (COMT). Velocity of this metabolism depends on the COMT-Val158Met-polymorphism. This effect is generally known by the term “imaging genetics”. Adult ADHD subjects showed a stronger activation in the OFC in the DD category “delayed” than in the category “now”. Measured impulsivity correlated with the cortical brain activity “DD-Kontrast”. No significant relation between the COMT polymorphism an the cortical brain activity or behaviour could be shown. The stronger activation of the OFC in the category “delayed” underlines the thesis of “Delay Aversion” from the “Dual Pathway Model”. A close connectivity between the dopaminergic corticostriatal brain regions of the amygdala and the OFC, which have an influence to the ADHD pathology, seem to be a plausible approach.

Attention-deficit/hyperactivity disorder (ADHD) is characterized by hyperactivity, impulsive behavior, and excessive in attention. The diagnosis is divided into different types of ADHD depending on the symptoms. A single cause for the diagnosis has not been found; therefore, various models exist. When choosing between an immediate smaller reward and a later larger reward, ADHD-diagnosed individuals often choose the immediate smaller reward, termed choice impulsivity (CI). Several models have tried to explain this phenomenon. One theory argues that the subjective value of the reward diminishes when the reward is moved furtheraway in time. Others claim that it is a deficit in inhibitory-based executive dysfunction and that ADHD individuals cannot suppress the drive and resist the temptation of the earlier reward. The delay aversion model argues that it is a motivational problem with an abnormality in the reward mechanism making the patients hypersensitive to delayed rewards. The negative affective state that evokes from the delayed rewards makes them want to escape or avoid it and therefore choose the small, immediate reward. The insula and the amygdala mediate both negative and positive emotional processes in the brain and are candidates for this phenomenon. In this systematic review, four scientific studies were selected and included to investigate if the insula and amygdala are the primary CI candidates in ADHD-diagnosed individuals. The systematic review results support the idea that the amygdala correlates with CI in ADHD-diagnosed individuals, therefore supporting the delay aversion model theory of ADHD. A correlation between insula and CI in ADHD-diagnosed individuals could not be established in this systematic review. Understanding the role that emotional structures have in ADHD can help to develop interventions or therapy to cope with the disadvantaged features of ADHD.

ADHD (Attention Deficit Hyperactivity Disorder) is a commonly diagnosed mental disorder with an estimated global prevalence of 5.29% that exhibit inattentive, hyperactive and impulsive behaviors, many of which can negatively impact an individual’s social, academic, occupational and everyday-life. Studies based on the Delay Aversion Hypothesis have shown that video-games effectively contribute to the neutralization of some of the inattentive symptoms of ADHD, and that games could act as a possible treatment option for individuals with ADHD. Attempts to use video games as a treatment option has previously been tried, however to a limited extent. This study approaches the topic from the game design perspective, and discusses which game mechanics, activities and stimuli contribute to the possible neutralization of the inattentive symptoms of ADHD, in order to lay a foundation for future research within the area. The study found that the participants with ADHD acted in ways that contradicted some of the described symptoms of ADHD in the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders) when playing video games, which could be attributed to the amount of stimuli available in video games. Additionally, the participants’ level of motivation when playing video games seemed to be strongly correlated to the principles of andragogy, which could indicate that children with ADHD might benefit from an educational system that combines and incorporates principles from both andragogy and pedagogy.

Objective: The strong association between ADHD and cigarette smoking and the known effects of nicotine on cognition has lead to interest in the role of cholinergic function in ADHD cognitive deficits. We have previously demonstrated that acute nicotine improves behavioral inhibition in adolescents with ADHD. This study examined acute nicotine in young adults with ADHD-Combined type on cognitive domains including behavioral inhibition, delay aversion, and recognition memory. Methods: 15 non-smoking young adults (20 ± 1.7 years) diagnosed with ADHD-C received acute nicotine (7 mg patch for 45 min) and placebo on separate days. Cognitive tasks included the Stop Signal Task, Choice Delay task, and the High-Low Imagery Task (a verbal recognition memory task). Three subjects experienced side effects and their data was excluded from analysis of cognitive measures. Results: There was a significant (p < .05) positive effect of nicotine on the Stop Signal Reaction Time measure of the Stop Signal Task. The SSRT was improved without changes in GO reaction time or accuracy. There was a trend (p = .09) for nicotine to increase tolerance for delay and a strong trend (p = .06) for nicotine to improve recognition memory. Conclusions: Non-smoking young adults with ADHD-C showed improvements in cognitive performance following nicotine administration in several domains that are central to ADHD. The results from this study support the hypothesis that cholinergic system activity may be important in the cognitive deficits of ADHD and may be a useful therapeutic target.