Unravelling the Link Between Sensory Processing Sensitivity and Medication Sensitivity

Study background and aims

The reaction to medication can vary greatly from person to person, with some individuals experiencing severe side effects while others may tolerate the same treatment without any issues. One factor that could explain such differences is Sensory Processing Sensitivity (SPS), a biological trait characterized by heightened sensitivity to environmental stimuli (1,2).

Unpacking sensitivity’s impact on medication reactions

The aim of our research (3) was to investigate the link between SPS and medication sensitivity by exploring whether people with high SPS are more likely to report heightened sensitivity to medications, even when accounting for factors like gender and negative affectivity. Understanding this connection is crucial for advancing personalised medicine, where treatments are tailored to individual differences, ultimately improving the effectiveness and safety of medical interventions.

Study design and methods

How was our study carried out?

We employed a meticulous methodology across three distinct studies, involving diverse participant groups, differing in age and gender distribution, from university samples and online platforms.

The first study involved 125 psychology students (average age 18-30), primarily female, from a university in the USA. The second study surveyed 214 participants, aged 18-77, recruited via advertisements and social media. The third study, the largest of the three, included 351 participants aged 19-81 from Amazon Mechanical Turk.

To examine the relationship between SPS and medication sensitivity, we asked participants to complete a set of questionnaires. Each study used the Highly Sensitive Person (HSP) scale to assess SPS (4) and scales to measure medication sensitivity (5, 6) and negative affectivity (7, 8, 9). In addition, in order to isolate the effects of SPS on medication sensitivity, we controlled for potential biases by adjusting for gender and the influence of negative affectivity.

Key findings

The connection between SPS and medication sensitivity

Across all three studies, we consistently found that individuals with higher SPS reported greater sensitivity to medication compared to individuals with lower levels of SPS:

• Study 1: Found a moderate correlation (r = 0.34, p < 0.001) between SPS and medication sensitivity.
• Study 2: A smaller but still significant correlation (r = 0.21, p = 0.003) was observed.
• Study 3: With the largest sample size, the correlation was again moderate (r = 0.36, p < 0.001), confirming the previous results.

Notably, the relationship between SPS and medication sensitivity remained the same for men and women and was found over and above the relationship between SPS and negative affectivity, a characteristic commonly linked to SPS.

What are the implications of these findings?

Tailoring treatments for sensitive individuals

Our findings could have significant implications for how we approach treatment in healthcare settings. Given that SPS is associated with medication sensitivity, medical professionals might consider:

• Adjusting Dosages: Highly sensitive individuals might need lower medication doses to avoid adverse effects, ensuring treatments are both safe and effective.
• Screening for Sensitivity: The HSP scale could be used to screen patients, allowing healthcare providers to identify individuals who may be more sensitive to medications, enabling personalised treatment plans.
• Improving Adherence: By minimising side effects, highly sensitive individuals might be more likely to stick to their prescribed treatments, leading to better overall health outcomes.

The study also highlights how biologically-based traits like SPS affect not just how we process the world around us, but also how we respond to medication. This could be a stepping stone for further research into other areas of healthcare, including pain management and psychotherapy, where sensitivity may play a role.

General conclusion

This study confirms what many may have suspected: around 20–33% of the population, those classified as highly sensitive, are more likely to experience stronger reactions to medication. Recognising SPS as a factor in medical treatments can help make healthcare safer and more effective for those with heightened sensitivity. By adjusting treatment plans to account for SPS, clinicians could improve patient outcomes, making medicine truly personalised.