Mood disorders, including major depressive disorder, appear to be more common in those with developmental disorders, including autism spectrum disorder (ASD) than in the general population. However, diagnosing depression in ASD represents a challenge that dates back to Leo Kanner’s original description of “infantile autism” in 1943. Kanner described a disturbance of “affective contact” in those with autism. Clinicians use the term “affect” to describe how someone’s emotional state appears to others. In other words, does the person look depressed or anxious? This is different from “mood.” Mood refers to how someone actually feels inside. Affect and mood are not always aligned. For example, someone’s expression may appear flat and they may show little emotional reactivity. However, that person may say that he or she feels fine. Alternatively, someone may present with laughter and giddiness and say they feel anxious or upset. Clinicians refer to this as an “incongruence of affect and mood.”
Many individuals with ASD show little facial emotion or reactivity. This does not necessarily mean they’re depressed. In other words, their affect doesn’t necessarily match how they feel. This mismatch between affect and mood, however, does make it more difficult to recognize and diagnose depression in someone with ASD. Limited verbal output or lack of speech can be an issue for up to 25% of person with ASD making it challenging for the clinician to assess the individual’s mood state. When clinicians are conducting a diagnostic evaluation on a neurotypical patient, especially an adult, they place a great deal of significance on the words the patient uses to describe their mood or how they feel. Not having access to this information can make it more difficult for the clinician to make an accurate diagnosis of a mood or anxiety disorder. It is important that clinicians not make assumptions about how a person with ASD with minimal to no speech feels. As discussed above, this can lead to an inaccurate interpretation because the person’s mood and affect my not be congruent. Even those individuals with ASD that have communicative language may not be able to identify or label their feelings accurately. They may not fully comprehend what the term “mood” means when we ask them; they may truly not know how they feel.
These factors can make it challenging to accurately diagnose depression in those with ASD. There are other strategies a clinician can use, however, to gather the information necessary to make a diagnosis of depression in these patients. We can ask about other symptoms that commonly occur in depression. These include changes in appetite or sleep, which can be either increased or decreased. There may be a significant drop in energy or lost ability to experience pleasure in activities that had been enjoyable. This may come with an overall decrease in interests and motivation. We can measure changes in weight and ask caregivers to monitor the hours of sleep and type of sleep the individual is getting. Still, it’s difficult to confidently diagnose depression in those who may not be able to convey how they feel verbally or non-verbally. A very important question to ask the patient, caregivers, and treatment team is “Has there been a significant change in the individual’s overall daily function compared to the recent past, that has persisted in a consistent pattern over the past few weeks or longer?” If the answer to this question is “Yes,” then the onset of a major psychiatric event or episode or an underlying medical problem “presenting” like depression should be strongly considered and investigated.
Another challenge in diagnosing depression in someone with ASD is the overlap in symptoms between the two conditions. The symptoms of depression include a flat or depressed affect (facial expression), reduced or increased appetite, sleep disturbance, low energy, reduced motivation, social withdrawal, and reduced desire to communicate with others. Many of these same symptoms can be present in ASD rather than depression.
When discussing the diagnosis and treatment of depression, it is always important to address the possibility of suicidal thoughts and behaviors. In medical training, psychiatrists learn to assess every patient for the risk of suicide, especially those with depression. We should not make assumptions about the thoughts or feelings of another individual. We can’t know if a person is having thoughts about suicide unless we ask them and they tell us. This includes those with developmental disorders like ASD, including individuals with minimal to no speech. In a recent study published in the journal Research in Autism Spectrum Disorders, Angela Gorman et al. identified a number of risk factors associated with thinking about suicide and suicide attempts in children with ASD. Through parent interviews, the researchers inquired about 791 children with ASD, 186 typically developing children and 35 non-autistic children with diagnosed depression. The percentage of children rated by their parents as “sometimes” to “very often” contemplating or attempting suicide was 28 times greater for those with ASD than those with typical development. It was three times less among those with ASD than among the non-autistic children who had depression. Depression was also the strongest single predictor of suicidal thoughts or attempts among the children with ASD. Fortunately, suicidal tendencies were uncommon among children under age 10 years.
These findings underscore how important it is for clinicians to assess the potential for suicide whenever evaluating children, adolescents or adults with ASD. Yes, we are challenged in making an accurate diagnosis of depression and assessing suicide risks in individuals with ASD, but it is imperative that we use all the information available to us for this purpose. This should include direct interaction with and observation of our patients, as well as gathering collateral information from family members, teachers, job coaches, group home staff, and so on.
Despite the fact that depression is more common in individuals with ASD and other developmental disorders, very little research has been conducted to investigate the causes and precipitants of depression in this population or to identify effective treatments. In fact, to date, there has not been even one systematic clinical trial of an antidepressant medication for treating depression in individuals with ASD of any age, cognitive level of functioning, or diagnostic subtype published in the worldwide medical literature! We urgently need more research to develop better tools and techniques for diagnosing mood disorders, like major depressive disorder, in individuals in ASD. This is particularly important for those who have significant communication difficulties. It is possible that the use of augmentative and alternative communication devices may help in this regard. Moreover, we critically need research that advances the development of effective medications and behavioral treatments for depression in ASD. It may be that the challenges of accurately diagnosing depression in persons with ASD have contributed, in part, to this lack of progress. However, this is not a valid or acceptable reason for the lack of pursuing the development of effective treatment interventions for our patients. We must address the challenges of diagnosing depression in persons with ASD and redouble our efforts to identify effective treatment interventions and preventative strategies.
Featured image credit: Woman and Child by George Hodan. Public Domain Via publicdomainpictures.