A systematic review of the behaviours associated with depression in people with severe-profound intellectual disability

The assessment of depression in people with severe to profound intellectual disability (severe-profound ID) is challenging, primarily due to inability to report internal states such as mood, feelings of worthlessness and suicidal ideation. This group also commonly presents with challenging behaviours (e.g. aggression and self-injury) with debate about whether these behaviours should be considered 'depressive equivalents' or are sensitive for, but not specific to, depression in severe-profound ID. We conducted a systematic review exploring behaviours associated with depression and low mood in individuals with severe-profound ID. The review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (2009) guidelines. Three electronic databases were searched (Embase, PsycINFO and Ovid MEDLINE), and 13 studies were included and rated for quality. Few studies were rated as having high methodological quality. Behaviours captured by standard diagnostic schemes for depression (e.g. Diagnostic and Statistical Manual of Mental Disorders and International Classification of Diseases) showed a relationship with depression in severe-profound ID, including the two core symptoms (depressed affect and anhedonia), as well as irritability, sleep disturbance, psychomotor agitation, reduced appetite and fatigue. Challenging behaviours such as aggression, self-injury, temper tantrums, screaming and disruptive behaviour were associated with depression. Challenging behaviours show a robust relationship with depression. Whilst these behaviours may suggest an underlying depression, study limitations warrant caution in labelling them as 'depressive equivalents'. These limitations include not controlling for potential confounds (autism, other affective disorders and pain) and bias associated with comparing depressed/non-depressed groups on the same behavioural criteria used to initially diagnose and separate these groups. Future studies that use depressive measures designed for ID populations, which control for confounds and which explore low mood irrespective of psychiatric diagnosis, are warranted to better delineate the behaviours associated with depression in this population (PROSPERO 2018: CRD42018103244).

Beyond symptom control for attention-deficit hyperactivity disorder (ADHD): what can parents do to improve outcomes?

Attention-deficit hyperactivity disorder (ADHD) and its associated behavioural manifestations develop and progress as the result of complex gene-environment interactions. Parents exert a substantial influence and play a major role in their child's social environment. Despite this, recent evidence has suggested that adapting the child's environment via parenting interventions has minimal effects on child ADHD symptoms when analysing data from informants who are probably blind to treatment allocation. However, adverse parenting and family environments may act as a source of environmental risk for a number of child outcomes beyond ADHD symptoms. This is a narrative review that critically discusses whether parenting interventions are beneficial for alternative functioning outcomes in ADHD including neuropsychological, academic and social functioning and disruptive behaviour and how parenting and familial environments may be associated with these outcomes. In addition, the review explores how parental depression and parenting efficacy impact on capacity for optimal parenting and whether parenting interventions benefit parents too. A review of the evidence suggests that with modification, parenting interventions are beneficial for a number of outcomes other than ADHD symptom reduction. Improving the parent-child relationship may have indirect benefits for disruptive behaviour. Furthermore, parenting behaviours may directly benefit child neuropsychological, academic and social functioning. Parenting interventions can have therapeutic benefits for parents as well as children, which is important as parent and child well-being is likely to have a transactional relationship. Evaluation of the clinical success of parenting interventions should focus on a wider range of outcomes in order to aid understanding of the multifaceted benefits that they may be able to offer. Parenting interventions should not be seen as a redundant adjunct to medication in multi-modal treatment approaches for ADHD; they have the potential to target outcomes that, at present, medication seems less able to improve.

Attention-deficit hyperactivity disorder (ADHD): an updated review of the essential facts

Attention-deficit hyperactivity disorder (ADHD) is a complex disorder that can affect individuals across the lifespan. It is associated with substantial heterogeneity in terms of aetiology, clinical presentation and treatment outcome and is the subject of extensive research. Because of this, it can be difficult for clinicians to stay up to date with the most relevant findings and know how best to respond to parents' questions and concerns about the disorder and interventions. This is a narrative review that aims to summarize key findings from recent research into ADHD and its treatment that clinicians can share with families in order to increase their knowledge about ADHD and intervention options. ADHD develops as a result of complex interplay between interdependent genetic and non-genetic factors. The disorder is associated with substantial impairments in functioning and poor long-term outcomes. Pharmacological and non-pharmacological treatment options are available for symptom management and to improve function, but functioning outcomes often fail to normalize in children with ADHD. Despite extensive advances in understanding this complex disorder, it is clear that there is still a long way to go. In particular, we address the need for future non-pharmacological interventions to be more specifically targeted for ADHD symptoms and its commonly associated functioning deficits in order to ensure the best long-term outcomes for children with ADHD.

Modelling the Formation of Polycentric Chromosome Aberrations

Exchange-type chromosome aberrations produced by ionizing radiation or restriction enzymes are believed to result from pairwise interaction of DNA double-strand breaks (dsb). In addition to dicentrics, such aberrations may include higher-order polycentrics (tricentrics, tetracentrics, etc.). We have developed computer programs that calculate the probability of the various polycentrics for a given average number of pairwise interactions. Two models are used. Model I incorporates kinetic competition between restitution, complete exchanges (illegitimate recombination events), and incomplete exchanges. Model II allows unrestituted breaks even if there is no recombination. The models were applied to experimental observations of aberrations produced in G1 Chinese hamster ovary cells after electroporation with the restriction enzyme PvuII, which produces blunt-end dsb. We found, experimentally and theoretically, that there was a maximum in the number and multiplicity of polycentrics per cell: beyond a certain PvuII concentration no additional or higher-order polycentrics were produced. Computer-generated relationships, which were remarkably similar for both models and for all values of the adjustable parameters, were found between dicentrics per cell and higher-order polycentrics per cell. Excellent agreement was found between the experimental observations and the consensus theoretical curve relating tricentrics per cell to dicentrics per cell. The observed number of higher polycentrics per cell for a given number of dicentrics per cell was somewhat larger than the consensus theoretical prediction. The observed number of centric rings per cell was markedly larger than the consensus theoretical value, presumably owing to intrachromosomal localization ('proximity effects'). The computer models also provided estimates for the adjustable parameters; for example, in model I the fraction of incomplete exchanges was found to be about 35%.