Journal of Intellectual Disability Research最新文献

Background

Research in people without ID suggests that both traumatic events (i.e., A criterion events) and stressful life events (i.e., non-A criterion events) can produce PTSD symptoms. However, research on this subject in ID populations is limited. The discussion about the usefulness of Criterion A (i.e., the stressor criterion) as a gate criterion for PTSD in the DSM-5-TR is particularly important for people with mild intellectual disabilities (MID) or borderline intellectual functioning (BIF) because of their vulnerability to stressors. This study aimed to compare PTSD symptoms and impairment of daily life functioning (IDLF) score following traumatic versus stressful index events in people with MID-BIF.

Methods

The Diagnostic Interview Trauma and Stressors–Intellectual Disability (DITS-ID) was administered to 54 participants with MID-BIF. Two groups were generated based on the type of index event (i.e., traumatic or stressful). Bayesian equivalence testing was used to assess whether the two groups differed in terms of PTSD symptoms and IDLF score.

Results

Data were more consistent with either a small difference or no difference at all between the traumatic (N = 22) and stressful group (N = 32) regarding the mean number of PTSD symptoms and the mean IDLF score. Differences in PTSD symptoms and IDLF scores ranged from 0.00 to 0.87.

Conclusion

No clinically relevant differences were found between the traumatic and stressful groups in terms of mean number of PTSD symptoms and IDLF score. Stressful life events might produce PTSD symptoms in people with MID-BIF.

Background

Off-label antipsychotic use in people with intellectual disabilities and challenging behaviour is high. Antipsychotic withdrawal is recommended, but attempts are often unsuccessful. This study aimed to develop and internally validate a prediction model that provides insight into predicting factors for unsuccessful (i.e. incomplete) off-label antipsychotic withdrawal attempts in people with intellectual disabilities.

Methods

Data collected in two previous studies examining the withdrawal of off-label antipsychotics in people with intellectual disabilities and challenging behaviour living mostly in 24/7 care settings (98.6%) in the Netherlands were analysed. The dataset included 141 participants (64.5% male, median age 52). We selected candidate predictors (age, level of intellectual disability, defined daily dose, autism spectrum disorder and three subscales of the Aberrant Behavior Checklist [ABC], namely stereotypy, hyperactivity and lethargy) based on previous research and clinical relevance. A multivariable logistic regression analysis with backward selection procedures was conducted to identify significant predictors. The model was internally validated using bootstrapping procedures.

Results

The analysis revealed the level of intellectual disability (p = 0.030, OR = 2.374), defined daily dose (p = 0.063, OR = 2.833), and ABC stereotypy (p = 0.007, OR = 1.106) as key predictors for unsuccessful withdrawals. The variables explained 20% of the variance (Nagelkerke's R-square, R² = 0.200). The model calibrated well as the Hosmer and Lemeshow test was not significant. The discrimination of the model was fair to good; the Area Under the Curve (AUC) was 0.728. Internal validation procedures showed an optimism-corrected AUC of 0.706; the optimism-corrected Nagelkerke's R² was 0.157.

Conclusions

The odds of unsuccessful withdrawal increase with a more severe level of intellectual disability, a higher antipsychotic defined daily dose and higher stereotypy scores. The results inform healthcare providers about the predictive factors enabling them to better anticipate and support future withdrawal attempts.

Background

Special education teachers require foundational reading content knowledge (e.g., phonemic awareness, phonics) to teach early reading skills. Though many measures have been developed to measure such knowledge, none have examined item-level differences related to teacher characteristics (i.e., experience, degree and instructional time use).

Method

In this study, we examined the psychometric properties of the 20-item Teacher Knowledge Assessment: Structure of Language scale using data from 337 special education teachers providing reading instruction to students with intellectual and developmental disabilities in the United States.

Results

Out of 20 possible total points for correctly answered items, the average score was 13.2 (SD = 3.5). We conducted Rasch analysis and dropped two misfitting items, resulting in 18 items on the scale (M = 11.9; SD = 3.3). Using dichotomous teachers' years of experience (≤ 5 years vs. > 5 years), education level (bachelor's or below vs. advanced) and self-reported time teaching phonics and phonemic awareness (≤ 20% vs. > 20%) as focal variables, we conducted differential item functioning (DIF) analyses as part of the Rasch analysis. A greater number of items showed DIF for teacher experience or instructional time use (8 items each) than for degree (3 items), with easier and harder items identified for each subgroup.

Conclusions

These results evince inconsistencies in teachers' acquired foundational reading knowledge based on experience, degree and instructional time use. Structured literacy standards for teacher preparation programmes and in-service training initiatives may provide the means to address gaps in teachers' knowledge.

Background

Significant memory impairments are consistently observed in individuals with intellectual disabilities (ID), but considerable variability exists. This study investigated the heterogeneity of declarative memory in children and adolescents with nonspecific mild intellectual disability (NSID) to identify distinct memory profiles and potential predictors of this disability.

Methods

A latent profile analysis (LPA) was conducted on a large sample (N = 999, including 114 with NSID) using six supplementary memory indices from the Test of Memory and Learning—Second Edition (TOMAL-2). A logistic regression analysis subsequently examined the predictive power of TOMAL-2 indices for NSID diagnosis.

Results

LPA revealed two distinct memory profiles: a ‘memory impaired group’ (24% of the total sample) with below-average scores across all indices and a ‘high-performers group’ (76%) with consistently above-average scores. Individuals with NSID were significantly more likely to belong to the ‘memory impaired group’. Logistic regression analysis revealed that lower scores on the Attention/Concentration Index, Sequential Memory Index and Verbal Delayed Recall Index were the strongest predictors of NSID. However, notably, 25% of individuals with mild NSID were classified in the ‘high performers group’, exhibiting typical or above-average memory scores across multiple indices.

Conclusions

This study demonstrates significant heterogeneity in declarative memory among individuals with NSID, challenging the assumption of uniform impairment. The identified memory profiles and predictive indices offer valuable insights for more precise diagnostic assessment and the development of tailored interventions. Further research should investigate the factors contributing to this variability and explore the potential of these findings for improved support and educational strategies.

Trial Registration: NCT06215092

Background

Angelman syndrome (AS) is a developmental disorder caused by one of four molecular aetiologies. Affected individuals have intellectual disability (ID), limited speech, seizures and sleep problems. Parents of individuals with AS exhibit elevated stress compared to parents of individuals with other IDs. We examined parental stress and family quality of life (FQOL) over time in families of individuals living with AS.

Methods

Data were collected in a natural history study of AS. The Parenting Stress Index, Third Edition (PSI) and the Beach Center FQOL Scale assessed parental stress and FQOL. Stress and FQOL were examined across AS molecular subtypes, and predictors were analysed using a generalised linear model. Relationships between parental stress and FQOL were examined using Pearson correlations and a stepwise mixed-linear model approach.

Results

Our sample consisted of 231 families of individuals living with AS. Parental stress was clinically elevated and was highest in families of individuals with UBE3A pathogenic variants, whereas FQOL did not differ across subtypes in most domains. Increasing age predicted a decrease in parental stress but did not predict FQOL. Elevated parental stress was additionally predicted by maladaptive behaviours and child male sex, whereas lower FQOL was predicted by child male sex, parent marital status and family income. Parental stress had a small negative impact on FQOL.

Conclusions

Stress is elevated in parents of individuals with AS across subtypes and has a negative impact on FQOL. Interventions to reduce stress have the potential to improve individual and family well-being.