Observable Symptoms of Anxiety in Individuals with Fragile X Syndrome: Parent and Caregiver Perspectives

Abstract

Caregiver reports, clinical observations, and diagnostic assessments indicate that most individuals with fragile X syndrome experience high levels of chronic anxiety. However, anxiety is a challenging endpoint for outcome measurement in FXS because most individuals cannot reliably report internal emotional or body states. A comprehensive survey of the presence, frequency, and duration of anxiety-related symptoms and questions to elicit open-ended responses was completed by caregivers of 456 individuals with FXS, ages 2-81 years (87 female, 369 male) and 24 female and 2 male FXS self-advocates ages 15-66 years. Caregivers reported classic behavioral indicators of anxiety, such as avoidance, irritability, motor agitation, and physiological symptoms, as well as behavioral features in FXS such as repetitive behavior, aggression, and self-injury. Self-advocate accounts largely paralleled caregiver data. Factor analyses yielded four factors: (1) increased irritability, aggression, and self-injury; (2) increased physical movement, nervous activity, and restlessness; (3) physical and physiological features of anxiety; and (4) internalizing and gastrointestinal symptoms. Caregivers are capable of observing and reporting behaviors that are valid indicators of anxious states that are usually reported in self-report standardized assessments. These results support the development of an anxiety measure for FXS that minimizes problems with rater inference.

Keywords: FMR1 gene; assessment; autism; intellectual disability.

Figure 1

Proportion (a) and frequency (b) of females with FXS reported by caregivers to show specific behaviors or verbal symptoms when they believe the individual is experiencing anxiety.

Figure 2

Proportion of males and females with FXS reported by caregivers to experience specific physical symptoms when they believe the individual is experiencing anxiety.

Figure 3

Proportion of males with FXS, within each age group, reported by caregivers to show specific behaviors or verbal symptoms when they believe the individual is experiencing anxiety.

Figure 4

Frequency of behaviors by age in males with FXS reported by caregivers. 1 = rarely when they are anxious, 2 = sometimes when they are anxious, 3 = about half the time when they are anxious, 4 = usually when they are anxious, 5 = always when they are anxious.

Figure 5

Duration of caregiver-reported specific behaviors and verbal symptoms associated with anxiety in males with FXS. 1 = less than 1 min, 2 = 1–5 min, 3 = 6–15 min, 4 = 16–60 min.