Is there evidence of a causal link between childhood maltreatment and attention deficit/hyperactivity disorder? A systematic review of prospective longitudinal studies using the Bradford-Hill criteria.

Background: Studies report an elevated risk of maltreatment in children with attention deficit/hyperactivity disorder (ADHD), and elevated levels of ADHD in people who suffered childhood maltreatment (CM). However, the direction(s) of causality between CM and ADHD remain unclear-does ADHD create a context for CM, does CM cause ADHD, or both? Objective: This study systematically reviews and qualitatively synthesizes the research evidence relating to this question using Bradford-Hill criteria for establishing causality-strength, temporality, dose-response and plausibility. Methods: We conducted a systematic review, following PRISMA guidelines, of prospective longitudinal studies examining both CM and ADHD. We then used Bradford-Hill criteria to assess the quality of evidence for a causal link between CM and ADHD. Results: All 11 included studies demonstrated an association between CM and ADHD. Seven included evidence for temporality: five suggesting that CM precedes ADHD in the lifespan; two suggesting ADHD precedes CM. Four studies demonstrated a dose response relationship in which greater CM exposure was associated with elevated risk of ADHD. Studies presented a range of plausible mechanisms, including CM causing ADHD through biological programming, versus ADHD causing CM through parental stress. Conclusions: The high quality prospective longitudinal studies reviewed confirm the association between ADHD and CM, but present conflicting evidence about the direction of causality and mechanisms underpinning this association. To better understand the complex interplay between CM and ADHD, more studies using new research designs will be required that can partition effects by type of CM and account for bidirectional effects and other complexities.

Psychometric properties of the Revised Child Anxiety and Depression Scale in Greek Adolescents.

The psychometric properties of the Revised Child Anxiety and Depression Scale (RCADS-47) are established cross-culturally but lacking for the Greek population. The present study examined RCADS internal consistency and validity (structural and concurrent) in Greek adolescents, and tested measurement invariance across sex and age groups. We recruited 619 secondary school students (n = 321 females), aged 12-18 years (n = 318, 12-14-year-olds). Besides RCADS, all students completed Strengths and Difficulties Questionnaire (SDQ), a subsample (n = 300) completed Screen for Child Anxiety-Related Emotional Disorders (SCARED), whereas a non-overlapping subsample (n = 219) completed Depression Self-Rating Scale (DSRS). Structural validity was examined with Confirmatory Factor Analysis and measurement invariance was assessed with Multiple Indicators Multiple Causes (MIMIC) modeling. Convergent and divergent validity were examined using Spearman correlations between RCADS subscales and DSRS, SCARED, and SDQ validators. The six-factor model fitted the data best, validating the originally proposed RCADS structure. Three items displayed differential item functioning for sex, another three for age group, and one item for both, albeit with trivial effect sizes (d < 0.2). Cronbach's alpha was .94. Convergent and divergent validity were also established. In conclusion, the RCADS is a valid and reliable instrument for assessing anxiety and depression symptoms in Greek adolescents.

Diverse patterns of vulnerability to visual illusions in children with neurodevelopmental disorders.

Research on how children with neurodevelopmental disorders perceive, process, and interpret visual illusions (VIs) has been extensively focused on children with autism spectrum disorder providing controversial findings. In this study, we investigated the patterns of vulnerability to a wide set of VIs comprising 23 standard text book VIs and their variations in a clinical sample of children with neurodevelopmental disorders compared to typically developing children (TD). A total of 176 children, aged between 4.6 and 13.8 years old, were distributed into four groups: high-functioning autism (HFA; N = 23), attention-deficit/hyperactivity disorder (ADHD; N = 42), specific learning disorder (SLD; N = 70), and TD (N = 41). Regression models, adjusted for sex, age, and non-verbal IQ, showed that HFA was associated with greater responses accuracy than TD children to the full battery of VIs, to the cognitive illusions, to the distortions, and to both geometrical illusions of size/shape (cognitive distortions) and lightness contrast effects (physical distortions). The susceptibility of ADHD children was found attenuated for illusory contours and greater for paradoxical illusions in comparison with TD children. No significant differences were shown between the SLD group and the TD children. Our findings, which were adjusted for the same duration of visual working memory across groups, showed that there is a potential specific tendency of HFA children to failure of processing visual information in context. Contrarily, children with ADHD showed in general normal global processing such as children diagnosed with SLD.

Salivary cortisol and alpha-amylase daily profiles and stress responses to an academic performance test and a moral cognition task in children with neurodevelopmental disorders.

There is evidence that children with neurodevelopmental disorders may exhibit atypical responses to stress and alterations in concentrations and diurnal secretion of stress hormones. We assessed diurnal profiles and stress responses of salivary cortisol and alpha-amylase (sAA) in children with attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and specific learning disorder (SLD) compared to typically developing children (TD). A total of 157 children of both sexes, aged between 6 and 12 years old, took part in the study distributed into four groups: ADHD (N = 34), ASD (N = 56), SLD (N = 43) and TD (N = 24). Salivary samples were collected at three time points during a day, as well as before and 5 min after an academic performance test and a moral cognition task. ADHD children had lower evening and diurnal sAA levels, adjusted for age. Also, ASD children showed lower diurnal sAA secretion, adjusted for age. The mean percentage change for salivary cortisol and sAA after both tests did not differ between the groups. In conclusion, we demonstrated alterations in diurnal autonomic functioning in children with ADHD and ASD, while hypothalamic-pituitary-adrenal axis functioning did not differ between the clinical and the comparison groups.