[P2-2] Retrospective study of behavioral and psychiatric problems in people with intellectual disability
[Introduction] Because little is known about the time course of behavioral and psychiatric problems in people with intellectual disability (ID), we studied a group of these patients retrospectively. [Methodology] We reviewed the medical records of sixty 20-year-old patients with ID that described their developmental quotient (DQ) (divided into two groups, <35 or ≥35), the presence of a comorbid autism spectrum disorder (ASD) and the presence of any of 6 behavioral problems (self-injurious behavior, hyperactivity, excessive resistance to change, temper tantrums, aggressive behavior and hyper- or hypo-reactivity to sensory input) and 3 psychiatric problems (sleep, anxiety and pica) in three age ranges (0-6, 7-12 and 13-20 years old). [Results] The 60 participants included 39 males and 21 females. Twenty-nine participants had DQ <35, and 42 had an ASD. The incidence rates of self-injurious behavior and anxiety increased, while those of hyperactivity and hyper- or hypo-reactivity to sensory input significantly decreased with age. Gender was related to the incidence rates of hyperactivity and excessive resistance to change only. The problems associated with the DQ gradually increased with age. A comorbid ASD was more strongly related to the incidence rates of almost all problems than any other items, and there were more problems associated with an ASD in the age range of 7-12 years than in other ranges. [Conclusions] Behavioral and psychiatric problems vary with age. A comorbid ASD and the DQ affect the incidence of such problems age-dependently.