Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT04779632 |
| Other study ID # |
D227 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
December 10, 2019 |
| Est. completion date |
February 13, 2020 |
Study information
| Verified date |
March 2021 |
| Source |
University of Copenhagen |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The prevalence of autism spectrum disorder (ASD) is rising and was estimated to have a
prevalence of around 1.5% in developed countries in 2016. ASD is characterized by impairments
in social interaction and repetitive behavior and is associated with executive dysfunction
such as impaired working memory, inhibition, and flexibility. Furthermore, ASD is often
associated with multiple comorbidities such as attention-deficit/hyperactivity disorder
(ADHD), depression, and anxiety.
Systematic reviews and meta-analyses indicate that fish oil (FO) supplementation improves
attention, impulsivity, and hyperactivity in children with ADHD and beneficial effects in
adults with depression and anxiety. Some randomized trials in children with ASD have shown
improvements on selected executive functions, but results from meta-analysis are inconsistent
and no trial has examined the effect in adults with ASD. Furthermore, most of the previous
studies have mainly assessed effects by questionnaires and no objective tests, only provided
low doses (<1.5 g/d of n-3 long-chain polyunsaturated fatty acids) and none of them have
examined the potential influence of comorbid ADHD, depression, or anxiety.
The aim of the study was to examine the effect of FO on sustained attention and visuospatial
short-term memory memory, as well as cognitive inhibition, executive function, and core
symptoms of ASD, and of ADHD, and social function in adults with ASD. In light of the shared
and additive cognitive impairments in individuals with both ASD and ADHD, the hypothesis was
that individuals with comorbid ADHD will show the most pronounced effects. The study
furthermore aimed to examine potential interaction with depression, anxiety, and gender.
This was investigated in a randomized double-blind head-to-tail crossover trial in 26 adults
with ASD, who are provided with FO and safflower oil (SO) for 4 weeks each. The subjects were
examined at baseline and after each period with tests of attention and working memory
(primary endpoints) as well as a test of cognitive flexibility and clinical questionnaires.
Description:
The aim of the study was to examine the effect of fish oil (FO) on sustained attention and
visuospatial short-term memory memory, as well as cognitive inhibition, executive function,
and core symptoms of ASD, and of ADHD, and social function in adults with ASD. In light of
the shared and additive cognitive impairments in individuals with both ASD and ADHD, the
hypothesis was that individuals with comorbid ADHD will show the most pronounced effects. The
study furthermore aimed to examine potential interaction with depression, anxiety, and
gender.
This was investigated in a 2 × 4 week randomized double-blind head-to-tail crossover study
with FO and safflower oil (SO).
Participants were recruited by advertisements posted in autism-related institutions and
autism forums on Facebook as well as via personal networking. The study aimed to recruit up
to thirty participants and ended up with twenty six participants.
The intervention in the two periods consisted of four capsules two times per day of FO
(corresponding to approximately 5,2 g/d long-chain polyunsaturated fatty acids) and SO (1.2
g/day of linoleic acid), respectively. The intervention sequences: FO → SO or SO → FO was
determined by a randomization list generated by a person, who was not involved in the data
collection and FO and SO capsules were packed in white containers of similar appearance in
the same known excess amount of what was required for four weeks. The participants were
allotted to one of the intervention sequences by ID numbers based on date and time of their
first visit and were provided with the appropriate pre-ID labelled container in the beginning
of each period.
The participants were examined at baseline and after each period. The assessment consisted of
the following: attention (The d2 Test of Attention) and spatial working memory (Corsi
Block-Tapping Test) as primary outcomes and as secondary outcomes, inhibition and flexibility
(The Stroop Word-Color Test), ADHD symptoms (Conners Rating Scale), and executive and social
functions assessed by the Behavioral Inventory of Executive Function and Social
Responsiveness Scale, respectively. Compliance was verified by whole-blood fatty acid
analysis.
