Seizures are more common in individuals with intellectual disabilities than in the general population. As a result, differences in functioning for individuals with intellectual disability with and without seizures have been evaluated. Research on differences in psychopathology for individuals with intellectual disability with and without seizures has been mixed. The purpose of this study was to examine differences in subscale scores on the Diagnostic Assessment for the Severely Handicapped-II (DASH-II) between individuals with intellectual disability with and without seizures. In this study, 321 individuals from two large developmental centers in the southeastern United States were administered the DASH-II. Researchers found that the seizure group endorsed significantly more symptoms on the mood subscale than the group without seizures. No other group differences were found to be significant. Implications of these results are discussed.► Seizures occur frequently in persons with intellectual disabilities. ► The co-occurrence of psychopathology, seizures, and intellectual disability have been documented. ► Mood symptoms appeared more frequently in persons with co-occurring intellectual disability and seizures compared to intellectual disability alone.
Intellectual disability (ID) affects almost 3% of the population and is accompanied by a host of related problems such as challenging behaviors and developmental delays (Dixon et al., 2010, Eriksson et al., 2010, Matson and Shoemaker, 2009, Smith and Matson, 2010a, Smith and Matson, 2010b, Sturmey et al., 2010a, Sturmey et al., 2010b and Weeden et al., 2010). Additionally, epilepsy occurs more frequently in individuals with developmental disabilities than in the general population (McDermott et al., 2005). The prevalence of epilepsy in individuals with developmental disabilities varies depending on the type of disability and the age of the individual (McDermott et al., 2005). McDermott et al. (2005) found that 25.5% of individuals with intellectual disability also had epilepsy. Similarly, in a study by McGrother et al. (2006), the prevalence of epilepsy in adults with intellectual disabilities (ID) was 25.6%.
Differences in functioning between individuals with ID and epilepsy and individuals with ID without epilepsy have been researched. For example, in adults with moderate to profound ID, epilepsy has been associated with poorer understanding, a greater risk of physical problems, and more difficulties with activities of daily living (McGrother et al., 2006). Also, a history of seizures has also been associated with a reduced lifespan for individuals with developmental disabilities (Hanson, Nord, & Weiseler, 1997).
Researchers have also investigated the relationship between epilepsy and psychopathology symptoms, as well as epilepsy and challenging behaviors, in individuals with ID. McGrother et al. (2006) found that after controlling for demographic variables including age and sex, as well as degree of understanding, individuals with ID and epilepsy displayed more problems with noncompliance, night disruptions, and attempts to get attention than individuals with ID without epilepsy. Also, mood swings were found to be more prevalent in individuals with epilepsy than those without.
Smith and Matson, 2010a and Smith and Matson, 2010b found no significant differences in psychopathology symptoms when comparing individuals with ID and epilepsy to individuals with ID alone. Psychopathology symptoms were also comparable across individuals with ID and autism spectrum disorder (ASD) and individuals with ID alone; however, individuals with ID, epilepsy, and ASD displayed more psychopathology symptoms (i.e., increased anxiety, irritability, and depression) than the other three groups, including individuals with ID alone, individuals with ID and ASD, and individuals with ID and epilepsy.
Deb and Hunter, 1991a and Deb and Hunter, 1991b examined the prevalence of challenging behaviors and psychiatric disorders in individuals with ID and epilepsy compared to individuals with ID without epilepsy. They failed to find significant overall differences in challenging behaviors between individuals with and without epilepsy. The authors, however, found psychiatric disorders to be more prevalent in individuals without epilepsy. Matson, Bamburg, Mayville, and Khan (1999) found individuals with ID without a seizure disorder to have higher ratings of psychopathology and aberrant behavior scores on the Diagnostic Assessment for the Severely Handicapped-II (DASH-II) and the Aberrant Behavior Checklist (ABC), respectively, than individuals with ID and a seizure disorder. This study, however, did not report which types of psychological symptoms were more common in individuals with ID without a seizure disorder.
Results are mixed at this point regarding the relationship of seizures to psychopathology in general and specific psychopathology symptoms in individuals with ID. This fact is largely due to the paucity of studies in the area and differing methodologies. This paper expands on previous research by looking more closely at specific mental health symptoms in individuals with ID with and without seizures.
