Dietary supplements for aggressive behaviour in people with intellectual disabilities: A randomised controlled crossover trial

BACKGROUND

Aggressive incidents are common in people with intellectual disabilities. Therefore, we aimed to assess whether supplementation of multivitamins, minerals, and omega-3 fatty acids (FA) reduces aggressive incidents.

METHODS

We conducted a randomised, triple blind, placebo controlled, single crossover intervention trial. People with intellectual disabilities or borderline intellectual functioning, between 12 and 40 years of age, and showing aggressive behaviour were included. Participants received either a daily dose of dietary supplements, or placebo. Primary outcome was the number of aggressive incidents, measured using the Modified Overt Aggression Scale (MOAS).

RESULTS

there were 113 participants (placebo, n = 56), of whom 24 (placebo, n = 10) participated in the crossover phase of the trial. All 137 trajectories were included in the analyses. There was no significant difference in mean number of aggressive incidents per day between those assigned to supplements and those who received placebo (rate ratio = 0.93: 95% Confidence Interval [CI] = 0.59-1.45).

CONCLUSION

In this pragmatic trial, we did not find significant differences in the outcomes between the supplement and placebo arms. The COVID-19 pandemic started midway through our trial, this may have affected the results.

Lessons learned from two clinical trials on nutritional supplements to reduce aggressive behaviour

BACKGROUND

Setting up and conducting a randomised controlled trial (RCT) has many challenges-particularly trials that include vulnerable individuals with behavioural problems or who reside in facilities that focus on care as opposed to research. These populations are underrepresented in RCTs.

APPROACH

In our paper, we describe the challenges and practical lessons learned from two RCTs in two care settings involving long-stay psychiatric inpatients and people with intellectual disabilities. We describe five main difficulties and how these were overcome: (1) multisite setting, (2) inclusion of vulnerable participants, (3) nutritional supplements and placebos, (4) assessment of behavioural outcomes, and (5) collecting bio samples.

CONCLUSIONS

By sharing these practical experiences, we hope to inform other researchers how to optimally design their trials, while avoiding and minimising the difficulties that we encountered, and to facilitate the implementation of a trial. Both trials were registered in the Clinical Trials Register (RCT A: NCT02498106; RCT B: NCT03212092).

Diet quality among people with intellectual disabilities and borderline intellectual functioning

Background

We sought to assess diet quality among people with intellectual disabilities or borderline intellectual functioning, living in residential facilities or receiving day care.

Methods

We measured diet quality using the Dutch Healthy Diet Food Frequency Questionnaire (DHD) and compared this between participants with (n = 151) and controls without intellectual disabilities (n = 169). Potential correlates of diet quality were explored.

Results

We found lower mean diet quality among people with intellectual disabilities (M = 80.9) compared to controls (M = 111.2; mean adjusted difference −28.4; 95% CI [−32.3, −24.5]; p < .001). Participants with borderline intellectual functioning and mild intellectual disabilities had lower diet quality and higher body mass index than individuals with severe to profound intellectual disabilities. Being female was a predictor of better diet quality.

Conclusions

Overall, we found that diet quality was low in the sample of people with intellectual disabilities or borderline intellectual functioning.