Background

The point prevalence of epilepsy in childhood and adolescence has been estimated at between 0.3-0.6%. It has been known for many years from cross-sectional surveys that children with epilepsy have particularly high rates of psychiatric disorders (34.3-37%) when compared to children with other common chronic medical conditions (11-11.3%) and that depression rates especially are particularly high, with reports of upto 26% reported. Depression and depressive symptoms have a high impact on children and adolescents with epilepsy and on their families.

The reasons for the high rates of depression in children with epilepsy are not well understood. One of the most established associations for depression is the female preponderance in prevalence of depression which merges around the time of puberty. This female preponderance is however not found for individuals with epilepsy. A small study found marked differences in gender patterns in depression rates amongst adolescents with epilepsy compared to adolescents with other chronic diseases with adolescent males with epilepsy showed significantly higher rates of depression than males with asthma whereas females with epilepsy were at much lower risk than females with asthma. Moreover there is evidence that that the pattern of depressive symptoms for children and adolescents with epilepsy are also different from that found in the general population.

One possible factor that may explain some of these differences from the general populations is that epilepsy commonly coexists with other neurodevelopmental problems, notably intellectual disability(15-38% of individuals with intellectual disability affected by epilepsy) autistic spectrum disorders, ASD (epilepsy present in 8-28% of those with autism) and Attention Deficit Hyperactivity Disorder, ADHD (ADHD present in 38% of children with epilepsy) that are themselves associated with increased rates of depression. Thus depression risk could be better explained by the cluster of multiple brain/neurodevelopmental problems rather than by epilepsy alone. There are mixed findings from studies on whether it is the presence of other neurodevelopmental problems such as intellectual disability that indexes increased risk of depression amongst adolescents with epilepsy.

It is also not clear whether the association of increased risk of depression is only for those with epilepsy or extends to all those who have experienced non-febrile convulsions. Many children and adolescents experience non-febrile convulsions in a given year but only a minority are labelled as having epilepsy. For many of these children seizures are attributed to a specific cause but for others there is no cause noted and these are labelled as single unprovoked seizures. However there is little long term follow information on this non-epilepsy seizures group as most studies are cross sectional. Moreover detailed characterisation of this group (e.g. co morbidity, prognosis) is lacking although a high prevalence of psychological and social problems are found in individuals labelled as having non-epileptic seizures. Given that both misdiagnosis and underdiagnosis of epilepsy have been identified as issues better characterisation of the non-febrile non -epilepsy group to examine natural history and co morbidity would seem timely.

The overall aim of this proposal is to build on our previous work on adult epilepsy and begin a new programme of neuropsychiatric and psychology research on epilepsy in children and adolescents. The overall scientific aims are to better understand the clinical presentation and processes linking depression with paediatric epilepsy and identify which children are at greatest risk. Longitudinal assessments of epilepsy,non-epilepsy convulsions, asthma and depression across puberty and additional information on commonly co morbid disorders and other psychological and social covariates and outcomes will allow testing of our key hypotheses.

The specific aims of the proposal are

1. To explore whether in children with epilepsy the pattern of depression symptoms and pattern of associations (such as with age, gender, family adversity and social disadvantage) are similar 1) to those for children with asthma) and 2) and to children with non-febrile convulsions but no definite diagnosis of epilepsy

2. To examine the influence of puberty in depression rates for adolescents with depression as compared to adolescents with asthma and adolescents with no other chronic medical condition.

3. To examine the relationship between depression symptoms and adolescent epilepsy. Particularly 1) in temporal order of development of each problem (depression and epilepsy) 2) the effect of co-morbidity (ADHD, Intellectual disability) in explaining any associations uncovered 3) the role of seizure frequency, adjusting for the presence of other co morbid conditions, in predicting depression symptoms.

Practical importance of the topic

There is a paucity of community based mental health research on children with epilepsy particularly focusing on identifying those children at high risk of adverse outcomes. Depression is a key factor determining the quality of life of individuals and their families. This research will provide evidence to inform management strategies for children with epilepsy and should be of help to clinicians and families. For example if a sub-group of children at particular risk of adverse psychopathological outcomes are found this will enable development of appropriate interventions and targeting of clinical resources to this group. If risk pathways to depression in children with epilepsy are different from those in the general population, this would influence clinical management and prevention.

Research design

Samples

This consists of information from parents and children from 14 541 pregnancies. We will include information from children with epilepsy aged between 8 1/2 years and 15 years. Information on epilepsy related convulsions, non-epilepsy non-febrile convulsions, asthma and depression and anxiety are available at 4 data points and will be used for the analysis) We will include all children with epilepsy (31 at age 10) and social class, gender and severity match an equivalent number of children with asthma (selected out of 935 children with asthma) and individuals with non-epilepsy non-febrile convulsions.

Current data required:

Epilepsy: Mother questionnaire reports of convulsions (both attributed to epilepsy and non febrile non-epilepsy and frequency if available ) at ages 103 months, 128 months , 140 months, 157 months and 166 months (KS, KV, KW, TA, TB).

Asthma: Mother questionnaire reports of asthma at ages 103 months, 140 months, 157 months and 166 months (KS, KV, TA, TB)

Depression and anxiety : Mother questionnaire reported depression and anxiety using MFQ items 115 months(KU), 140 months (KW)

Child reported depression and anxiety using SMFQ items: 126 month(focus 10+), 150months (12.5years) (TF1), 13.5 years (TF2) and DAWBA interview 15.5 years (186 months(TF3)).

SDQ infirmation from KU(115 months) (includes information on peer problems (e.g. bullying), Hyperactivity symptoms)

Autism, Dyspraxia, Dyslexia- from KU questionnnaire 115 months

DAWBA interview ADHD diagnoses (91 months)

IQ scores

Age (child at assessment)

Gender

Social class

Family history of depression

Lifestyle factors: diet parent reported (KT (103m) KU(115m)) self reported CCM (156 months), sleep (KU 115 m, KV 128m, KW 140m TB 166m)