Predicting aggression in children with ADHD

ADHD is one of the most prevalent childhood disorders, and it is a community health problem that may result in significant psychiatric, social and academic problems if not treated. ADHD frequently co-occurs with other psychiatric disorders [1,2]. Research shows that aggression is an important associated feature of ADHD, and it is essential in understanding the impact of the disorder and its treatment [3]. The presence of comorbid aggression in ADHD does not appear to be spurious, and the severity and/or presence of aggression and ADHD may significantly impact its long-term prognosis. The etiology of aggression in ADHD is not clearly understood. However, aggression can be considered to be an outcome of the interaction between genetic and environmental factors [4]. Aggression is thought to be inherited, and the concordance of maternal twins is between .28 and .72 [5]. Compared to children who only have ADHD, it is more likely that children with ADHD and ODD or CD have fathers with an Antisocial Personality Disorder. Pfiffner et al. [6] found that children who have fathers with Antisocial Personality Disorder are more at risk for developing behavioral problems.

The most significant family factors influencing the occurrence of aggression in ADHD are as follows: large family size, the attitude of the family towards aggression, disciplinary or negative parenting, low socio economic status and family conflict [7]. Extended family and low socio economic status may cause aggression as a result of inadequate attention.

Parental attitudes are particularly important in psychiatric disorders, including aggression and ADHD [8]. However, there is a gap in the literature regarding the nature of the relationship between negative parental attitudes and psychiatric disorders that influence childhood aggression. The debate over whether aggression in children caused by parents’ lack of interest and/or their hostile and critical attitudes towards their children, or whether negative parenting is instead caused by children’s behavioral problems remains unresolved [9].

Cognitive deficits primarily in the verbal area play a role in the etiology of aggression. Previous data regarding the interaction between cognition and aggression reveal such general cognitive predictors of aggression as lower intelligence quotients, reading difficulties, and problems associated with attention and hyperactivity [10]. Many studies suggest that aggressive children experience problems in social cognitive areas [11,12] and have lower IQ scores [13,14]. In a meta-analysis of twenty-seven studies, seventeen studies reported negative associations between cognitive functions and disruptive behaviors [15].

Some of the most comprehensive research examining the relationship between ADHD and aggression using advanced statistical analyses has been conducted by Miller et al. [16]. In that study, 165 children with ADHD and disruptive behaviors between the ages of 7 and 11 were tested using structural equation modeling (SEM) to determine the influence of family and cognitive factors on aggression. One of the most important characteristics of the study is that it attempts to explain aggression in children with ADHD with information from two sources: parents and teachers. Family factors including present and past aggression by parents and the number of siblings are examined. Cognitive factors, verbal IQ, reading and mathematical achievement are also examined. The study found that family factors are related to aggression at home and at school, whereas cognitive factors are only related to aggression at school.

The purpose of our study is to evaluate the influence of family, parent–child relations and cognitive factors on the development of aggression in children within a larger and a non-western sample. We use structural equation modeling and include information from the parents, teachers and the child as the information source. This method is ideal, as it is important to receive information from multiple sources to explain a multicomponent concept such as aggression. Accordingly, we include evaluations of the mothers’ acceptance or rejection of the child with ADHD in the structural equation model in addition to information received from parents and teachers. To our knowledge, this is the first study to consider information from the parent, teacher and the child regarding aggression in ADHD. In addition, we examine mother-child relationships in detail regarding the etiology of aggression [8,16], as we consider it crucial to include the perception of acceptance or rejection of children with ADHD by their mothers as a possible latent factor.

In our study, past and current aggression by the parents, the number of people living in the home and the number of siblings were used as family factors. To define cognitive factors in the present study, verbal and performance IQ and school success variables are used. To evaluate the perceptions of children regarding their mothers’ acceptance or rejection, warmth, aggression and rejection variables specified in the theory of parental acceptance and rejection are used [17].