Julia J. Rucklidge

BACKGROUND: Misconceptions about ADHD stigmatize affected people, reduce credibility of providers, and prevent/delay treatment. To challenge misconceptions, we curated findings with strong evidence base. METHODS: We reviewed studies with more than 2000 participants or meta-analyses from five or more studies or 2000 or more participants. We excluded meta-analyses that did not assess publication bias, except for meta-analyses of prevalence. For network meta-analyses we required comparison adjusted funnel plots. We excluded treatment studies with waiting-list or treatment as usual controls. From this literature, we extracted evidence-based assertions about the disorder. RESULTS: We generated 208 empirically supported statements about ADHD. The status of the included statements as empirically supported is approved by 80 authors from 27 countries and 6 continents. The contents of the manuscript are endorsed by 366 people who have read this document and agree with its contents. CONCLUSIONS: Many findings in ADHD are supported by meta-analysis. These allow for firm statements about the nature, course, outcome causes, and treatments for disorders that are useful for reducing misconceptions and stigma.

Background: Executive function, particularly behavioral inhibition, has been implicated as a core deficit specific to Attention‐Deficit/Hyperactivity Disorder (ADHD) whereas rapid naming has been implicated as a core deficit specific to reading disabilities (RD). Females may be less impaired in executive function although adolescent females with ADHD have yet to be studied. Method: Neuropsychological profiles of four adolescent groups aged 13–16 with equal female representation were investigated: 35 ADHD, 12 RD, 24 ADHD+RD, and 37 normal controls. A semi‐structured interview (K‐SADS‐PL), the Conners Rating Scales and the Ontario Child Health Study Scales were used to diagnose ADHD. RD was defined as a standard score below 90 on at least one of the following: Reading or Spelling of the WRAT3 or Word Attack or Word Identification of the WRMT‐R. The WISC‐III, Rapid Automatized Naming, Stroop and Stop tasks were used as measures of cognitive and executive function. Results: The two ADHD groups (ADHD, ADHD+RD) showed deficits in processing speed, naming of objects, poor behavioral inhibition and greater variability in reaction times whereas the two RD groups (RD, RD+ADHD) showed verbal working memory deficits and slower verbal retrieval speed. Only the comorbid group was slower with naming of numbers and colors and had slower reaction times. Regression analyses indicated that incongruent color naming (Stroop) and variability in go reaction time were the best predictors of hyperactive/impulsive ADHD symptoms whereas variability in go reaction time and processing speed were the best predictors of inattentive ADHD symptoms. Speed of letter naming and verbal working memory accounted for the most variability in composite achievement scores. No gender differences were found on any of the cognitive tests. Conclusions: This study challenges the importance of behavioral inhibition deficits in ADHD and that naming deficits are specific to RD. Further investigation into cognitive deficits in these groups is required. ADHD: Attention‐Deficit/Hyperactivity Disorder; RD: Reading Difficulties; SES: socio‐economic status; CTRS: Conners' Teacher Rating Scale; OCHSS: Ontario Child Health Study Scales; WRAT: Wide Range Achievement Test; WRMT: Woodcock Reading Mastery Test; MDD: Major Depressive Disorder; SAD: Separation Anxiety Disorder; GAD: Generalized Anxiety Disorder; OCD: Obsessive Compulsive Disorder; WISC: Wechsler Intelligence Scale for Children; RAN: Rapid Automatized Naming; SSRT: Stop Signal Reaction Time;

OBJECTIVES: This trial investigated whether probiotics improved mood, stress and anxiety in a sample selected for low mood. We also tested whether the presence or severity of irritable bowel syndrome symptoms, and levels of proinflammatory cytokines, brain-derived neurotrophic factor and other blood markers, would predict or impact treatment response. METHOD: Seventy-nine participants (10 dropouts) not currently taking psychotropic medications with at least moderate scores on self-report mood measures were randomly allocated to receive either a probiotic preparation (containing Lactobacillus helveticus and Bifidobacterium longum) or a matched placebo, in a double-blind trial for 8 weeks. Data were analysed as intent-to-treat. RESULTS: No significant difference was found between the probiotic and placebo groups on any psychological outcome measure (Cohen's d range = 0.07-0.16) or any blood-based biomarker. At end-point, 9 (23%) of those in the probiotic group showed a ⩾60% change on the Montgomery-Åsberg Depression Rating Scale (responders), compared to 10 (26%) of those in the placebo group ([Formula: see text], p = ns). Baseline vitamin D level was found to moderate treatment effect on several outcome measures. Dry mouth and sleep disruption were reported more frequently in the placebo group. CONCLUSIONS: This study found no evidence that the probiotic formulation is effective in treating low mood, or in moderating the levels of inflammatory and other biomarkers. The lack of observed effect on mood symptoms may be due to the severity, chronicity or treatment resistance of the sample; recruiting an antidepressant-naive sample experiencing mild, acute symptoms of low mood, may well yield a different result. Future studies taking a preventative approach or using probiotics as an adjuvant treatment may also be more effective. Vitamin D levels should be monitored in future studies in the area. The results of this trial are preliminary; future studies in the area should not be discouraged.