Factors Affecting Adherence in Patients with Intellectual Disabilities

Adherence can be a major concern when dispensing medications to individuals with intellectual disabilities. Pharmacists are in a position to help improve medication adherence in this patient population.

Patients with intellectual disabilities present many unique challenges for health care professionals, including pharmacists. When it comes to treating these patients with medication, adherence is a serious concern. Pharmacists should be aware of some of the factors that can impact medication adherence in patients with “intellectual disabilities,” a catch-all term that’s generally defined as limitations in mental abilities, communication, or other basic life skills. The prevalence of intellectual disability internationally is approximately 12 cases per 1000 individuals.1 In children, around 0.22 to 1.55% of the US population are affected.2 The severity of intellectual disability can vary from individual to individual; common causes include chromosomal abnormalities (such as Down syndrome) or brain injury. The disability itself, as well as associated social factors (socioeconomic status, living arrangements, etc.), can affect medication adherence. The World Health Organization considers psychological disability a condition-related barrier to medication adherence. Pharmacists should be aware of the following factors that can impact adherence in this patient population:

1. Patients with intellectual disabilities may not have the ability to fully understand the importance or impact of the medications they’re given. This altered perception or ability may have profound effects on treatment, particularly for chronic conditions.3

2. Patients with intellectual disabilities can also have various living situations, which can impart more challenges to medication therapy and adherence. These living arrangements can range from total independence to residing in group homes. It was found that patients with intellectual disabilities living in group homes had higher adherence rates compared with those who lived independently or in a family home.

3. Socioeconomic factors may impact these individuals’ ability to adhere to a medication regimen. Medicaid enrollment and minority race/ethnicity have been associated with reduced medication adherence in individuals with intellectual disabilities.4

Pharmacists should realize that those with intellectual disabilities and their caregivers may require additional counseling. Managing multiple medication regimens can pose a challenge for some. Tailoring counseling to the individual patient based on the level of disability has been shown to improve the understanding of the medications that they use.5 Determining the level of disability may be difficult, especially with new patients. Involving caregivers when possible may help to further improve communication and increase potential compliance with medication regimens.

Pharmacists are in a powerful position to positively impact pharmacotherapy in patients with intellectual disabilities. Building relationships with these individuals and their caregivers, developing effective communication techniques, and monitoring compliance more vigilantly have the potential to improve medication adherence in this at-risk patient population.


1. Maulik PK, Mascarenhas MN, Mathers CD, Dua T, Saxena S. Prevalence of intellectual disability: a meta-analysis of population-based studies. Res Dev Disabil. 2011;32(2):419-436. doi: 10.1016/j.ridd.2010.12.018.

2. McKenzie K, Milton M, Smith G, Ouellette-Kuntz H. Systematic review of the prevalence and incidence of intellectual disabilities: current trends and issues. Curr Dev Disorders Rep. 2016;3(104):1-12. doi: 10.1007/s40474-016-0085-7.

3. Sabaté, E. Adherence to long-term therapies: evidence for action. Geneva, Switzerland: World Health Organization Publications; 2003.

4. Tan X, Marshall VD, Balkrishnan R, Patel I, Chang J, Erickson SR. Psychotropic medication adherence among community-based individuals with developmental disabilities and mental illness. J Ment Health Res Intellect Disabil. 2015;8(1):1-22. doi: 10.1080/19315864.2014.959216.

5. Ferguson L, Murphy GH. The effects of training on the ability of adults with an intellectual disability to give informed consent to medication. J Intellect Disabil Res. 2014;58(9):864-873. doi: 10.1111/jir.12101.