J.J. Sandra Kooij, M.D., Ph.D.
Dr. J.J.S. Kooij, MD PhD & Dr. D. Bijlenga, PhD
Hypersensitivity in several sensory modalities is a feature of autism-spectrum disorder (ASD), and ‘hyper- or hyporeactivity to sensory input’ has been added to the criteria for an ASD diagnosis in DSM-5. Hyper- and hyposensitivity are described as atypical responses to any of the sensory modalities: vision, audition (hearing), touch, taste, olfaction, the vestibular system (balance), and activity level. In clinical ADHD populations, abnormal sensory sensitivity has also been reported, however research is scarce. Micoulaud-Franchi et al. (2015) showed that adults with ADHD have increased deficits in filtering out irrelevant auditory information such as the sound of a refrigerator turning on and off, which may be viewed as auditory hypersensitivity. Abnormal sensory sensitivity was especially related to increased inattention scores in ADHD. Auditory hypersensitivity has also been earlier reported in a study describing general functioning of a large group of adult ADHD patients (Kooij et al, 2001). Another study showed hypersensitivity to pain in adults with ADHD compared to norms (Treister et al, 2015). More studies have been done among children with ADHD. The systematic review by Ghanizadeh (2011) included 11 studies among children with ADHD, showing that in most of these studies, increased sensory sensitivity for all sensory modalities have been reported. Moreover, some studies indicate that the ADHD medication methylphenidate normalizes some of the sensory hypersensitivities, suggesting that the hypersensitivities are related to a dysregulated dopaminergic system.
As we know, in many cases, ADHD and ASD are comorbid. We investigated in this study the prevalence of sensory hyper- and hyposensitivity among 116 adults with ADHD, controlling for autistic symptoms.
We used the Adolescent/Adult Sensory Profile-NL (AASP-NL) and the Autism-spectrum Quotient (AQ) questionnaires. The prevalences of hyper- and hyposensitivity and autism-spectrum symptoms were compared to norm values.
As expected, adults with ADHD had more autistic symptoms than norm groups, and they reported also more hyper- and hyposensitivity compared to controls. This was especially apparent in the Activity level and Auditory sensory modalities. Sensory hypo- and hypersensitivity were both related to an increased ADHD score, even showing a dose-response relationship, but not to any autistic symptom or comorbid psychiatric disorder. As much as 43% of the females with ADHD reported sensory hypo- and/or hypersensitivity, compared to 22% of the men with ADHD.
Sensory hypo- and hypersensitivity may be viewed as key features of adult ADHD, especially in females, regardless of any autistic symptoms. Future research should be directed at the implications of this sensory dysregulation for the understanding of the pathophysiology of (female) ADHD, and on the usefulness of assessment of atypical sensory profiles in the diagnostic procedure of ADHD in adults.
References:
- Micoulaud-Franchi JA, Lopez R, Vaillant F, Richieri R, El-Kaim A, Bioulac S, et al. Perceptual abnormalities related to sensory gating deficit are core symptoms in adults with ADHD. Psychiatry Res 2015;230:357–63.
- Kooij JJ, Aeckerlin LP, Buitelaar JK. Functioning, comorbidity and treatment of 141 adults with attention deficit hyperactivity disorder (ADHD) at a psychiatric outpatients’ department [Dutch]. Ned Tijdschr Geneeskd2001;145: 1498–501.
- Treister R, Eisenberg E, Demeter N, Pud D. Alterations in pain response are partially reversed by methylphenidate (Ritalin) in adults with attention deficit hyperactivity disorder (ADHD). Pain Pract 2015;15:4–11.
- Ghanizadeh A. Sensory processing problems in children with ADHD, a systematic review. Psychiatry Investig 2011;8:89–94.