Effects of stress and relaxation on capsaicin-induced pain. Childhood methylphenidate treatment of ADHD and response to affective stimuli Dissociated effects of amphetamine on arousal and cortical blood flow in humans Relapse rate and subsequent parental reaction after successful treatment of children suffering from nocturnal enuresis: a 2 1/2 year follow-up of bibliotherapy. Caffeine effects on resting-state arousal The reinforcing effects of nicotine and stimulant medication in the everyday lives of adult smokers with ADHD: A preliminary examination. Aerobic Exercise Reduces Symptoms of Posttraumatic Stress Disorder: A Randomized Controlled Trial
A sizable body of research has been devoted to underst and ing the relationship between  pain sensitivity  and the psychological state of the individual . Considerable disagreement as to the direction of the association still exists . This study examines the effects of 2 experimental manipulations , cognitive/emotional stress and relaxation , on capsaicin-induced pain . Subjects were pretrained in relaxation and then r and  omized to experimental stress produced by a 20-minute Stroop test , relaxation ( tape ) , or a control condition ( neutral video ) , followed by a capsaicin injection in the forearm . Cardiovascular measures were taken at regular intervals , and cortisol , norepinephrine ( NE ) , and self-reports of arousal ( relaxation index ) were taken immediately before and after the experimental task . The manipulation significantly interacted with sex to predict capsaicin-induced maximum pain . Women in the stress condition reported greater pain than both men in the stress condition and women in the relaxation condition . Pain was correlated negatively with task-induced changes in NE and cortisol and positively with self-reported arousal ( decreased relaxation ) . However , separate analyses showed that some physiologic indexes of heightened arousal ( increased blood pressure and NE ) predicted lower pain only in men , whereas subjective increases in arousal predicted higher pain only in women . Multiple hierarchical regression analyses confirmed that physiologic and self-reported arousal predicted pain independently and in opposite directions , and a model including both accounted for 56 % of the overall variance . These findings suggest that a unidimensional model of arousal may be insufficient to explain the effects of stress on pain and that these effects operate differently in men and women Neural correlates of emotional dysregulation in attention-deficit/hyperactivity disorder ( ADHD ) and persisting influence of Methylpheni date ( MPH ) still remain insufficiently understood . Decreased activation in the subgenual cingulate and the ventral striatum were found during the perception of positive and negative affective pictures in drug-naïve males with ADHD during childhood ( n=10 ) . Males with ADHD during childhood treated with MPH ( n=10 ) did not show any significant differences compared to healthy controls ( n=10 ) . Further prospect i ve studies need to clarify direct and indirect mechanisms of MPH treatment that may contribute to emotional processing , which is dysfunctional in males without pharmacological treatment in childhood The effects of intravenous amphetamine infusion ( 0.3 mg/kg ) on cerebral blood flow ( CBF ) and measures of autonomic and behavioral arousal were studied in 12 normal male volunteers in a placebo-controlled crossover design . Nonsignificant decreases were seen in CBF ( measured by 133Xe inhalation ) , despite significant increases in autonomic and behavioral arousal . The apparent dissociation of CBF and arousal appears to be compatible with other human experiments suggesting that amphetamine decreases CBF and metabolism , as well as with neurobiological findings on the effects of catecholamines on resting cortical activity and mechanisms of increased attention . The results differ substantially , however , from findings of increased CBF and metabolism in animals . Although the larger doses used in animals most likely explain the discrepancy , technical limitations in human brain imaging can not be excluded Results 2 1/2 years after an enuresis nocturna training  are presented , including rate of success , percentage and duration of relapse for 113 children ( mean age 11.6 year at the start of the training ) . The bibliotherapeutic treatment by parents did not require any intervention by a professional . Behaviour of parents in the event of a relapse differed between training conditions . Children in the Arousal condition recovered faster from a relapse , 90 % of their parents used the  Arousal training  again at relapse or did not intervene at all and none of them consulted a professional . Clearly they had confidence in the method of Arousal training : combining the alarm device with reinforcement for correct behaviour at the time the alarm goes off . Parents in control conditions did not use the  alarm device as often as the parents in the Arousal condition , but tried other means with less success , including consulting professionals OBJECTIVE This study examined the use of caffeine to manipulate arousal level without the confounds associated with task-related activation . From previous work in our laboratory , an increase in skin conductance level ( SCL ) and EEG alpha frequency , together with a global decrease in alpha power , were used as markers of arousal increase , and we sought to identify these effects with caffeine ingestion . METHODS We examined the effect of a single oral dose of caffeine ( 250 mg ) in a r and omised double-blind placebo-controlled repeated- measures cross-over study . Eighteen healthy university students ( mean age 21 years ; 13/18 females ) participated in two sessions 1 week apart . EEG and autonomic data ( SCL , heart rate , systolic and diastolic blood pressure , and respiration rate ) from a 2 min eyes-closed epoch , commencing approximately 30 min after ingestion of caffeine or placebo , were examined . RESULTS Caffeine was associated with increased SCL , a global reduction in EEG power in the alpha b and , and a global increase in alpha frequency . There were no cardiovascular effects . CONCLUSIONS The positive results are consistent with recent electrodermal and EEG studies of arousal and suggest that caffeine may be utilised as a task-free means of manipulating arousal in future investigations . Further work is necessary to clarify the absence of cardiovascular effects , and to integrate those data with emerging conceptualisations of arousal and activation . SIGNIFICANCE The present data support the use of caffeine as a simple tool to explore the role of arousal in both normal and atypical functioning , and this may be useful in determining the validity and importance of supposed hyper- or hypo-arousal in such syndromes as attention-deficit/hyperactivity disorder ( AD/HD ) Whereas the smoking prevalence rates in the general population are declining , rates among people diagnosed with attention-deficit/hyperactivity disorder ( ADHD ) continue to be elevated . Previous research has shown that nicotine may improve attention and mood , suggesting that nicotine may help ameliorate the attentional and emotional problems associated with ADHD . The present study examined the effects of nicotine with and without stimulant medication on ADHD symptoms , moods , and arousal in the everyday lives of smokers with ADHD . A total of 10 smokers with ADHD who were being treated with stimulant medication  were asked to abstain from smoking while participating in the study . Participants underwent four conditions in r and omized order : ( a ) Nicotine patch+stimulant medication , ( b ) nicotine patch only , ( c ) placebo patch+stimulant medication , and ( d ) placebo patch only . Each condition continued for 2 days , during which self-reports of ADHD symptoms and moods were obtained using electronic diaries . Lightweight ambulatory monitors recorded cardiovascular activity at each diary entry . Smoking abstinence was verified by expired carbon monoxide and salivary cotinine analysis . Results showed that nicotine patches and stimulant medication alone and in combination reduced difficulty concentrating and core ADHD symptoms compared with placebo patch only . Borderline improvement in impatience and self-control was seen with nicotine patch administration primarily on day 1 . Nicotine patches also tended to elevate systolic and diastolic blood pressure compared with placebo patch during day 2 . The findings suggest that smokers with ADHD experience nicotine-related reductions in ADHD symptoms during their everyday lives Evidence suggests aerobic exercise has anxiolytic effects ; yet , the treatment potential for posttraumatic stress disorder ( PTSD ) and responsible anxiolytic mechanisms have received little attention . Emerging evidence indicates that attentional focus during exercise may dictate the extent of therapeutic benefit . Whether benefits are a function of attentional focus toward or away from somatic arousal during exercise remains untested . Thirty-three PTSD-affected participants completed two weeks of stationary biking aerobic exercise ( six sessions ) . To assess the effect of attentional focus , participants were r and omized into three exercise groups : group 1 ( attention to somatic arousal ) received prompts directing their attention to the interoceptive effects of exercise , group 2 ( distraction from somatic arousal ) watched a nature documentary , and group 3 exercised with no distractions or interoceptive prompts . Hierarchal linear modeling showed all groups reported reduced PTSD and anxiety sensitivity ( AS ; i.e. , fear of arousal-related somatic sensations ) during treatment . Interaction effects between group and time were found for PTSD hyperarousal and AS physical and social scores , wherein group 1 , receiving interoceptive prompts , experienced significantly less symptom reduction than other groups . Most participants ( 89 % ) reported clinical ly significant reductions in PTSD severity after the two-week intervention . Findings suggest , regardless of attentional focus , aerobic exercise reduces PTSD symptoms
Our literature review identified ANS dysfunction in individuals with ADHD , more often in the direction of hypo-arousal than hyper-arousal , particularly at rest and during tasks requiring response regulation and sustained attention .
Stimulant medications  increased ANS activity and , in some studies , reinforcers and rewards produced a similar effect , suggesting that ANS function can be modified in ADHD .
Although arousal mechanisms have frequently been found to be atypical in ADHD , these findings usually emerged from indirect behavioural measures which give only a limited underst and ing of arousal dysregulation in this condition .