According to the failure model (Patterson & Capaldi, 1990), peer rejection is the intermediary link between problem behaviors and internalizing symptoms. The present study tested the model with 464 monozygotic and same-sex dizygotic twin pairs (234 female, 230 male dyads). Teacher-reported reactive aggression and internalizing symptoms, and…

SATB2-associated syndrome (SAS) is a genetic syndrome characterised by intellectual disability, severe speech delay, and palatal and dental problems. Behaviours that challenge (BtC) are reported frequently; however, there is limited research on specific forms of BtC and the correlates of these behaviours. The current study explores correlates of…

The aim of this study is to use Q methodology to explore how school staff experience the behaviours of children with Smith-Magenis Syndrome (SMS) in school and how they manage working with these children. Q methodology utilises by-person factor analysis to investigate subjectivity. Fourteen school staff of students with SMS in Norway participated…

In this study, we examined trajectories of specific domains of behavior problems (i.e., attention problems, depression/anxiety, and aggressive behavior) from age 6 to 18 in a sample of 55 children with fragile X syndrome. We also examined autism status and early parenting as predictors of subsequent behavioral trajectories. We found that attention…

Background: People with 22q11.2 deletion syndrome (DS) are assumed to be especially vulnerable to developing mental illness such as psychosis. Aim: The study was established to contribute to knowledge about metyrosine medication in patients with 22q11.2 DS and psychosis. Methods: A case study was established including a woman with intellectual…

Limited information is available concerning the specificity of the forms and functions of aggressive behavior exhibited by boys with fragile X syndrome (FXS). To investigate these relationships, we conducted indirect functional assessments of aggressive behavior exhibited by 41 adolescent boys with FXS and 59 age and symptom-matched controls with…

Conduct disorder (CD) is a pattern of repeated aggression toward others, disregard for the rights of others, and behaviors that violate major social norms at home, in school, and even in society at large (American Psychiatric Association [APA], 2013). Falling under the umbrella of "conduct problems" along with oppositional defiant…

Background: There is limited research into the nature and aetiology of temper outbursts in people with intellectual disabilities. In this study, we describe the phenomenology and environmental context of temper outbursts in Lowe syndrome, a rare genetic syndrome in which outbursts are purportedly frequent. Method: A temper outburst interview (TOI)…

Using a dataset involving 415 individuals with irritability, aggression, agitation and self-injury (IAAS) behaviors from the fragile X syndrome (FXS) FORWARD database, we describe the psychopharmacologic management of IAAS and features of the population of persons with FXS treated with drug therapy for IAAS. Among those with FXS exhibiting IAAS,…

Background: Challenging behaviour, such as self-injury and physical aggression, is an issue of concern regarding a high proportion of individuals with fragile X syndrome. The aim of this review was to provide a comprehensive overview of the topographies and operant functions of challenging behaviours within the syndrome. Method: Five electronic…

Background: Phelan-McDermid syndrome is caused by a deletion at chromosome 22q13.3, and results in a phenotype characterised by intellectual disability, features of autism, physical and mental health conditions. It is becoming increasingly recognised that bipolar disorder represents part of this phenotype. Materials and methods: This case study…

The present study examined, within a longitudinal family-informed design and across middle childhood, the predictive associations between preference for solitude and social wariness, two forms of social withdrawal, and peer difficulties. Specifically, preference for solitude, rather than social wariness, was expected to predict peer victimization…

Self-injurious and aggressive behaviors are common in fragile X syndrome (FXS). However, little is known about the persistence of these behaviors and associated risk markers. We established the prevalence and persistence of self-injurious and aggressive behaviors over eight years in males with FXS, and associations with risk markers. Results…

Exposure to deviant friends has been found to be a powerful source of influence on children's and adolescents' aggressive behavior. However, the contribution of deviant friends may have been overestimated because of a possible non-accounted gene-environment correlation (rGE). In this study, we used a cross-lagged design to test whether friends'…

Background: Evocative gene-environment correlation (rGE) describes a process through which children's heritable characteristics influence their rearing environments. The current study examined if heritable influences on parenting and children's behavioral outcomes operate through child negative emotionality. Method: Using data from the Early…