Autism and intellectual disability - an interview with Alen Salkić
Alen Salkić gives us an overview of his research focusing on autism and intellectual disability
Please tell me a bit about yourself.
I work at the Child and Adolescent Psychiatry Outpatient Clinic (BUP) at Skaraborg Hospital, where I am employed as a specialist psychologist. My specialisation is in clinical child neuropsychology, a field I am deeply passionate about. Based on my academic background, which includes not only a degree in psychology but also studies in nursing and parts of a medical program (I hold a nursing license), my clinical interest has developed over time and is now scientifically oriented.
For most of my clinical career in specialised psychiatry, I have worked on assessments and evaluations of suspected developmental disabilities in children and adolescents. I have also been employed at the Child and Student Health Services, where I conducted evaluations of suspected intellectual disabilities (ID) in school-aged children.
In addition to my doctoral studies and clinical work, I undertake several other interesting assignments, both locally (LOTS: supervision of junior doctors) and regionally (Regional Process Team for ADHD/Autism/ID).
Please tell us how you got into research at the GNC
At the end of my specialist training, I needed to write a specialist thesis. I had an idea of what I wanted to write about and contacted Sebastian Lundström, a researcher affiliated with GNC. Sebastian responded quickly, broke down my thoughts, and wrote, "If you want to investigate all these questions, you’ll probably need to pursue a PhD; we’ll have to settle for one research question." We then conducted a clinical research study and examined the chosen research question. During this process, we applied for ethical approval, recruited study participants, conducted analyses, and wrote an article, which sparked my interest in clinical research. This led me, once the specialist thesis was completed, to draft a doctoral project and apply for research funding through my local R&D unit. When everything was finalised, I was registered as a doctoral student at GNC, with Sebastian as my primary supervisor.
What is your PhD project about?
My doctoral project focuses on autism and intellectual disability (ID), two developmental disorders that have historically been linked in terms of aetiology, prevalence, comorbidity, symptomatic similarities, and so on. With the increasing prevalence of registered autism diagnoses over the past two decades, questions about this connection have resurfaced, and my doctoral project aims to explore this. The themes of interest include comorbidity, symptomatic similarities and differences, differential diagnosis (i.e. distinguishing conditions with similar symptoms), diagnostic substitution (i.e. when a symptom profile is interpreted one way at one time and another way at a different time), and more. Three of my four studies are population-based, utilising data from various national registries. This allows us to address the above themes in somewhat more general terms.
What inspired you to pursue this research topic?
As a clinician, I have worked with this patient group for a long time and, for a certain period, quite intensively. As I gradually began to better understand the symptomatology and phenotype of each condition, some other interesting questions started to emerge. These questions arose from patient cases I had worked with, research articles I had read, discussions I had with colleagues, and my own reflections that have grown over the years. To now have the opportunity to try to find answers to these questions feels fantastic.
What are the main findings of your 1st paper, and why do you think they are significant?
In my first article, we examined the prevalence of intellectual disability (ID) among individuals with autism. We observed that the occurrence of ID within the autism group has significantly decreased over time, from approximately 55% in 2001 to around 8% in 2020. This trend has been observed, more or less, across all age groups studied within the cohort.
We also found that the prevalence of registered autism diagnoses during the same period has increased eightfold and that the average age at autism diagnosis has almost doubled, from about 8 years to around 15 years.
In light of these findings, we understand that individuals diagnosed with autism today are most often teenagers with average intellectual abilities. This confirms that the conceptualisation of autism, as well as the autism spectrum, has significantly evolved over the past twenty years.
Can you explain the methodology you used and why you chose it over other approaches?
The data for this study was extracted from two national registers: the Swedish National Patient Register (NPR) and the Halmstad University Register on Pupils with Intellectual Disability (HURPID). The NPR contains data on all diagnoses made in Swedish inpatient care from 1987 onwards, as well as diagnoses made in outpatient clinics from 2001 onwards. However, the NPR does not include data on intellectual disability (ID) diagnoses made in settings such as schools. Therefore, we supplemented the NPR data with information from HURPID, which covers this type of data.
We assessed that the data extraction method was appropriate as our study does not investigate the general prevalence of ID but rather the occurrence of ID among individuals with autism—a diagnosis made within healthcare settings. Our statistical analyses examined the prevalence of ID in individuals with autism both generally and with regard to the age at diagnosis over time. Given the study's research questions and purpose, this methodological approach was deemed the most suitable.
What challenges did you encounter during your research, and how did you overcome them?
In a way, I was mentally prepared for there to be challenges along the way. Some challenges or obstacles I have been able to anticipate, while others not at all. The obstacles I have been able to "remove" myself, I have tried to resolve together with my supervisors. Most of the challenges have been of an administrative nature, so it has required a lot of commitment, patience, and time.
How do you see your findings impacting the field (clinical or research) or influencing future research?
The results of our study confirm previous findings regarding the decreasing proportion of intellectual disability (ID) diagnoses within the autism group. What our study also demonstrates is that this trend has not diminished in any way but is likely to continue, given the significant increase in registered autism cases. Previous studies have generally shown that more severe symptomatology tends to be detected and diagnosed earlier, which is also, in a way, supported by our study. Individuals with registered autism today constitute a heterogeneous group with significant variations in terms of comorbidities, disabilities, etc. The patient group we focus on represents a small subset within the larger heterogeneous autism group.
How does your work fit into the existing literature on this topic?
The results of our study confirm previous findings regarding the decreasing proportion of intellectual disability (ID) diagnoses within the autism group. What our study also demonstrates is that this trend has not diminished in any way but is likely to continue, given the significant increase in registered autism cases. Previous studies have generally shown that more severe symptomatology tends to be detected and diagnosed earlier, which is also, in a way, supported by our study. Individuals with registered autism today constitute a heterogeneous group with significant variations in terms of comorbidities, disabilities, etc. The patient group we focus on represents a small subset within the larger heterogeneous autism group.
What are the next steps for your research, and are there any questions you still hope to answer?
Currently, we have two studies ongoing. One is a clinical study, so recruitment of study participants is in progress. We have encountered a number of different difficulties with this study, but we have not given up yet. The study aims at differential diagnosis between autism and intellectual disability, and we believe it will be of concrete clinical benefit. The second study is population-based (registry study) where we will focus on individuals with intellectual disabilities.
What advice would you give to other early-career researchers based on your experiences?
I am still learning and consider myself a beginner, so it's not so easy to give tips and advice to others. However, something I realised relatively early on is that things take time, and having a good dose of patience is always helpful. In this regard, I am working on becoming a bit better.
5 things about Alen...
- I am a self-taught keyboardist. Music is a great passion.
- am interested in many things, including languages and sports.
- I enjoy calligraphy. There is a difference between pens and pens.
- I like to be active and to discover new cities and countries with my family.
- I have soon lived half of my life in Sweden.
