A systematic review of the association of early life maternal depression and offspring ADHD, and an empirical study of cool and hot executive function, in relation to conduct and inattention/hyperactivity problems in young children.

This thesis was submitted as partial fulfilment for the degree of Doctorate of Clinical Psychology (DClinPsy) and comprises an empirical paper and a systematic review. The systematic review sought to understand the relationship of maternal depression and ADHD in the children of mothers who have experienced a period of depression, including during pregnancy. There are a variety of theories about how depression in mothers impacts upon rates of ADHD in children, some of which include shared genetic factors, changes in parenting practices, and an increase in other risk factors which may be related to an increased risk of ADHD, such as smoking during pregnancy. In order to assess the relationship between maternal depression and ADHD in children, the systematic review focussed upon longitudinal studies only. Three databases were used to collect the studies (Medline, Web of Science and PsychInfo), resulting in 1,223 studies being reviewed and fourteen articles being included in the review. Results indicated that a significant relationship between maternal depression and ADHD symptoms in children were reported in the majority of studies. This relationship was also significant when researchers took into account children’s early life temperament, or past ADHD symptoms. There were however several limitations of the studies reviewed including a bias towards wealthy westernised countries, limited consideration of the effect of fathers’ mental health on children and using measures of ADHD which were mainly completed by parents and may be less accurate. The empirical study looked at the relationship between executive function (a collection of brain processes which help us to think, plan, and problem solve) and symptoms of attention problems and hyperactivity, and conduct problems in young children. Although inattention/hyperactivity symptoms (e.g., fidgeting, not paying attention) and conduct problem symptoms (e.g., lying, 8 aggression) commonly co-occur, it is conduct problems which better predict the development of serious behaviour problems and antisocial/criminal behaviour later in life. Therefore, it is particularly important to understand which processes underlie each set of symptoms. One aspect of executive function is the ability to make decisions (e.g., by inhibiting incorrect responses and being flexible in how one responds) when having to manage our emotions under conditions of reward or loss, known as “hot” executive function. “Cool” executive function refers to similar skills but when there are no clear rewards/losses (and hence emotions are less activated). Previous research has found that symptoms of those with conduct problem disorders (such as Oppositional Defiant Disorder and Conduct Disorder), but not inattention/hyperactivity symptoms (including those diagnosed in Attention-Deficit Hyperactivity Disorder; ADHD) are associated with difficulties on hot executive function tasks. Likewise, past research has found that attention/hyperactivity problems, but not conduct problem symptoms are more strongly related to cool executive function. However, research on this topic in samples of younger children when problems are just beginning to develop is less common. The present study assessed cool and hot executive function in relation to inattentionhyperactivity and conduct problems, in a sample of children referred for emotional and behavioural problems (average age = 6.09 years). The study is important as understanding the underlying processes of particular symptom profiles will help inform the development of tailored preventative interventions in young children. Overall 132 children took part in the study. Each child was given a variety of tasks to complete, some of which assessed cool executive function,(working memory and cognitive flexibility), whilst other tasks related to hot executive function (reward-related decision-making tasks). Against our hypotheses, cool executive function was not significantly related to either inattention-hyperactivity or conduct problems. Also, against predictions, conduct problem symptoms were not uniquely related to scores on hot executive function tasks. However, further analysis on the hot executive function tasks found that children who had concurrent high inattention-hyperactivity and conduct problem symptoms had the poorest performance on hot executive function tasks, 9 including increased risk taking, slower learning, and they were less sensitive to punishment. It was therefore concluded that in young children, hot executive function difficulties appear to be related to a combination of inattention/hyperactivity and conduct problem symptoms