Thesis (M.A. (Psychology)) -- University of Limpopo, 2009 / Background: Although ADHD does occur as a single disorder in a minority of diagnosed individuals, it is generally comorbid with other behavioural and emotional disorders. The most frequent co-occurring psychiatric disorders are Oppositional Defiant Disorder, Conduct Disorder, Anxiety Disorder and Mood Disorder. The aim of the study was to establish a relationship between the core symptoms of ADHD (Inattention and Hyperactivity/Impulsiveness) and the externalising disorders, Oppositional Defiant Disorder and Conduct Disorder, and the internalising disorders anxiety and depression and to establish differences in comorbid symptoms (ODD, CD, anxiety, and depression) between children with ADHD and a non-ADHD control group as a function of gender and subtype. Method: A total of 100 Tsonga speaking primary school children (50 with ADHD symptoms and 50 non-ADHD controls) participated in the study. The ODD and CD scale of the Disruptive Behaviour Disorders rating scale was used to establish the symptoms of ODD and CD, while the Anxiety and Depression scales of the “Terry” Picture Questionnaire was used to establish the symptoms of Anxiety and Depression. Results: Findings of the study showed that the relationship between the hyperactive/impulsive component of ADHD and the externalizing disorders (ODD and CD) was moderate to strong, while there was no significant relationship between hyperactivity/impulsiveness and the internalizing disorders (anxiety and depression). The inattentive component of ADHD showed a strong relationship with ODD, but no significant relationship with CD was observed. The relationship of inattentive symptoms with the internalizing disorders (anxiety and depression) was weak to moderate. The comparison study showed that boys with the predominant hyperactive/impulsive subtype of ADHD had significantly more symptoms of CD than xii their non-ADHD counterparts, but not significantly more ODD symptoms, while girls of the predominantly hyperactive/impulsive subtype had significantly more symptoms of both ODD and CD than the non-ADHD girls. A comparison of the predominantly inattentive subtype of ADHD showed that the boys had more symptoms of ODD than their non-ADHD counterparts, while there were no significant extra symptoms for CD. The predominantly inattentive girls did not show more symptoms of both externalizing disorders than the non-ADHD controls. The ADHD-combined subtype had more symptoms of both disorders but no gender differences were observed. When the ADHD subtypes were compared with non-ADHD controls for internalizing disorders, only the predominantly inattentive subtype showed significantly more symptoms of both anxiety and depression. This was the case for both genders. Conclusion: The study showed that there is a relationship between the symptoms of ADHD (hyperactivity/impulsiveness and inattention) and the externalizing disorders, ODD and CD. Only the Inattentive component of ADHD showed a relationship with internalizing disorders (anxiety and depression). The comparison study showed that the predominantly hyperactive/impulsive and the combined subtypes displayed most symptoms of externalizing disorders, while the predominantly inattentive subtype had significantly more symptoms of internalizing disorders. Gender differences were observed in the symptoms of externalizing disorders, but not in the symptomatology of internalizing disorders.