Autism, Addiction, and Disordered Eating (OH MY!)

When consulting with mental and physical health clinicians, a disconnect exists between clinical expectations and the reality of comorbidity between Autism, substance use disorders (SUD), and disordered eating (DE). Research suggests that the risk of addiction is at least two-fold for Autists; however, clinicians often assume that unlike their allistic (or not Autistic) peers, autists are less likely to engage in potentially dangerous behaviors like substance use (among others, including risky sexual behaviors, impulsive shopping, gambling, etc.) (Walhout et al., 2022). This bias might stem from the tendency to infantilize Autistic people, viewing them as innocent and in need of protection. Autists are also stereotypically rule-governed, making them seem to be less likely to engage with unacceptable or "bad" behavior. Similarly, concerns about weight may focus on obesity as an issue of Autism, with data showing that 30% of Autists fall into the "obese" body category, overlooking the possibility of restrictive eating disorders like anorexia (Kahathuduwa et al., 2019).

On the other side of this issue, clinicians working in addiction and/or disordered eating tend to miss Autistic neurotypes among their clients, writing off their differences in function and behavior as a factor of the addiction and/or their personal history of dysfunction. It's not uncommon for clients under long-term care for specific issues such as addiction and disordered eating to be diagnosed late in life (e.g., in their 30s or later) as opposed to the more stereotypically-behaving Autist, who tends to be diagnosed in childhood, as early as at 18 months old (Lord et al., 2006). Autists who seek out treatment for substance use and disordered eating are likely to be treated as if they are allistic. Traditional treatment models are based on the neurotypical experience and are unlikely to work for Autistic clients, leading to Autists, their loved ones, and the clinicians invested in their recovery to attribute the failure to either the Autist themselves (e.g., they didn't really want to get better) or to the failure of the clinician (e.g., I am terrible at my job).

Autism and Substance Use Disorder

The co-occurrence of Autism and SUD has been explored infrequently, with the literature limited to the prevalence of what would be assumed to be "stereotypical" Autism and SUD that leads people to inpatient and/or justice system involved settings (Walhout et al., 2022). As is the case for many missed or lesser-known and studied populations, this means that there is a large gap in the understanding among mental health clinicians regarding the unique factors involved in the presentation and treatment of SUD among Autistic populations. Of the research that exists, the prevalence of Autism and SUD ranges from less than 1% to 50% or more (Walhout et al., 2022). Differences in prevalence rates are due to differences between studies such as in what qualifies as substance use as opposed to a substance use disorder, whether Autism was reported via self-report or psychological assessment, the settings from which samples were taken, and more. In studies exploring the possibility of Autism as a protective factor for developing a SUD, the opposite was found to be true (Santosh & Mijovic, 2006).

Autism is a risk factor for SUD.

Autists are more likely than their allistic peers to report using illicit substances recreationally (nine times more likely according to Weir, Allison, & Baron-Cohen, 2021), especially as they are helpful in reducing the effects of sensory overload, improve focus, and as a calming part of their routine. In Weir, Allison, and Baron-Cohen's (2021) study, participants also endorsed the use of substances as a method of masking (or camouflaging; for more on masking, please see Taking Off the Mask). Some Autists also report using recreational drugs as a substitute for prescription psychotropic medication, especially as side effects from some prescribed medications can be unpleasant.

SUD has many consequences, from increased risk or exacerbation of physical and mental health issues, accidents, violence, and suicide, and these consequences have been shown to be more impactful on Autists. Autists also experience increased  disruptions to routine and daily function, which then leads to even higher levels of distress and a cyclical increased reliance on substances to manage the distress (Arnevik & Helverschou, 2016). The needs among groups of people in substance abuse treatment and recovery without comorbid diagnoses and those with either Attention Deficit-Hyperactivity Disorder (ADHD) or Autism Spectrum Disorders were found to be significantly different, with  ADHDers requiring more of a coaching relationship with their nursing and support staff and Autists needing more of a psychoeducational and supportive role from their nursing staff (Kronenberg et al., 2015). These different needs were directly related to the treatment and sustained recovery of the clients. It is reasonable, then, to translate this difference in treatment style and methodology to mental health treatment needs of neurodivergent (e.g., ADHDers and Autists) in the mental health therapy room.

Despite these findings, SUD treatment recommendations for Autists continue to be guided by dominant cognitive-behavioral therapies (CBT) and abstinence treatment models, neither of which have been shown to sufficiently meet the needs of Autists as a whole. For more information about the issues in using a CBT framework with Autists, please explore the work of Spain et al. (2023) and others.

Autism and Disordered Eating

Before diving into the current understanding of Autism and DE in the literature, it's important to note that most research has been conducted on very specific samples: children and women. As a result of these limited samples, the experiences of adult Autists who do not identify as women and not assigned female at birth (AFAB) are lacking.

Difficulties with eating are extremely common among Autistic children and adults alike, with estimates being as high as 70% of Autistic children having issues with specific foods and/or eating as a whole. It is relatively common for Autists to report struggling with certain food textures, smells, or sounds, as well as some of the more socially governed aspects of eating (e.g., eating with a family, remaining seated, etc.). There is also an increased occurrence of gastrointestinal issues in Autistic samples, which can lead to difficulty with eating in general (Mayes & Zickgraf, 2019).

Most research and treatment attention on disordered eating among Autists has centered around weight-related concerns, as obesity is common for Autists, and Avoidant-Restrictive Food Intake Disorder (ARFID) (Leno, Micali, Bryant-Waugh, & Herle, 2022). There is also ample evidence linking Attention Deficit/Hyperactivity Disorder (ADHD) to binge eating disorder and other impulse control eating difficulties. ADHD is one of the most common comorbid conditions along with Autism, so it is worth considering the combined neurotypes and their link with eating as potential explanation and treatment guidance for eating difficulties among neurodivergent people broadly (Reinblatt, 2015). Anorexia nervosa (AN) is an additional common Autism comorbidity, especially among Autistic women and those AFAB. In samples of women being treated for AN, up to 35% also meet diagnostic criteria for an Autism diagnosis, with some researchers proposing a genetic link between Autism and AN (Brede et al., 2020; Koch et al., 2015). In addition to the proposed genetic and/or neurotype link between AN and Autism, many Autists with restrictive eating behavior report using restrictive eating behavior as a route to masking as well as a way to manage anxiety and distress. The repetitive nature of calorie counting, for example, can be reinforcing for Autists, leading to the eventual development of an eating disorder (Westwood & Tchanturia, 2017). The effects of undernourishment among Autists leads to a cyclical issue of increased sensitivity and heightened sensory difficulties, leading to emotional difficulties, reinforcing the relief found in the control around eating.

Treatment Recommendations for Eating Disorders are Often Ineffective for Autists

The treatment methodology in most disordered eating programs and facilities is frequently based on demanding immediate changes to eating routines that, for Autists, can be both impossible to navigate and cause additional distress, triggering an increased attachment to the routine. This heightened attachment can be viewed as inflexibility and treatment interfering behavior as opposed to a distinct difference due to neurotype requiring a shift in the needs of the client. Treatment facilities are rarely neurodiversity affirming, with harsh lighting, temperature, noise levels, etc. There is research supporting the idea that, even in cases where Autism is understood and reflected in adapting treatment to the individual, treatment may need to be longer term and more intensive (Tchanturia et al., 2019).

Despite research on the ineffectiveness of standard disordered eating treatment for Autistic women, very little research has been done to explore the ways that treatment could and should be improved. Field et al. (2023) is one of few studies exploring this, and they suggest several specific ways for treatment to be improved: training for clinicians on the difference between Autistic- and anorexia-based behavior (which would then lead to a treatment focus on actual disordered eating behavior as opposed to attempting to change neurotype-linked behaviors) and including Autists in the formation of treatment and adapting treatment to the unique needs of Autists (e.g., communication differences, sensory needs, etc.).

Biological Links Between Autism, SUD, & DE

The Dopamine Link

Dopamine is one of the primary neurotransmitters involved in processes related to social behavior and cognition, executive functions, motor control, motivation, arousal, reinforcement, and reward (Dangmanm, 2023). It is hypothesized that there is abnormal signaling by the dopaminergic system in specific brain areas among people with substance use and disordered eating.

The Serotonin Link

Serotonin is a neurotransmitter involved in many basic functions, including sleep and feelings of well-being. There is some research supporting the idea that people diagnosed with Anorexia Nervosa (and other eating disorders involving restriction and undernourishment) have higher levels of serotonin in their system and that the food restriction actually leads to a natural decrease in serotonin and improved sense of well-being (Kaye, Fudge, & Paulus, 2009). For those with low levels of serotonin, on the other hand, this deficit is one explanation for the typical cravings of high-calorie foods during binge-eating episodes, for example (Barron et al., 2017).

The Cortisol Link

Cortisol, a natural hormone linked to metabolism as well as stress and immune response, has been documented in higher levels among those with restrictive eating behaviors (especially AN) and also among Autists. Cortisol decreases appetite, and with long-term exposure, people experience decreased energy levels (Luz Neto et al., 2019).

The Insulin Link

Another proposed hypothesis is that the insulin signaling pathway has a disturbance. Some data supports this, with studies showing that autistic children tend to prefer energy-dense foods with low nutritional value. Additionally, autistic women are more likely to develop PCOS and insulin resistance than their allistic peers (Rivell & Mattson, 2019). While there is ample literature exploring the link between withholding insulin as a means for weight loss among diabetic patients, there is a lack of research exploring the link between disordered eating among non-diabetic samples (Winston, 2020). 

The Orexin-A Link

Orexin-A is a neuropeptide involved with arousal, emotional regulation, the sleep-wake cycle, and appetite, and levels of orexin-A tend to be elevated in autists. Additionally, dysfunction of this system has been associated with depression, anxiety, and addiction in the literature (Dangmann, 2023).

Specific Brain Region Links

The ventral-tegmental area (VTA), nucleus accumbens (NAc), and prefrontal cortex are involved in the "reward" circuit of the brain, and there are well-documented differences in these areas of the brains of autists as compared to allistic people (Dichter et al., 2012). Additionally, the prefrontal cortex, amygdala, and ventral striatum tend to function differently for autists, reflected by differences in social motivation and behavior (Clements et al., 2018). Third, the brain regions responsible for repetitive behavior, including the cortico-basal ganglia and the thalamic circuits, are different among autists and allistics. Lastly, there is ample data showing a distinct size difference in the hippocampi of autistic and allistic people, which autists having larger (and more dense) hippocampi than allistics.

Implications for Mental Health Treatment

When working with Autistic clients, it's vital for clinicians to understand the comorbidity of and boundaries between Autism and/or disordered eating and substance use. For many Autists, treatment focused on the difficulties of functioning in a world that is designed for and by neurotypical people can often decrease the desire/need to utilize food and/or substances to manage. It is not uncommon for clinicians without training in Autism (especially among adults) to focus treatment on substance use and/or disordered eating without any understanding or consideration of Autism. This misfocus on features that are functioning as helpful tools to manage the difficulty of Autism as problems means that many Autists are instructed to stop using their coping strategies without the implementation of any other effective coping strategies. This misfocus can lead to decreased function as opposed to improvement, leading to loss of hope, stigma around treatment interfering behavior, and more.

Additionally, for those clinicians working with disordered eating and/or substance use, it's important to be aware of the prevalence of clients with Autism within these treatment communities. Seeking continuing education on Autism, and the way that atypical Autism presents (especially in marginalized communities), is important for not only ethical care, but also for treatment success for Autistic clients.

To learn more about Autism and other forms of neurodivergence, please check out the KDH Collective Neurodivergent CEs and blogs.