A recent study published in The Ocular Surface found that higher neuroticism and lower conscientiousness are associated with greater odds of dry eye disease (DED), especially highly symptomatic DED.
Give me some background first.
As a multifactorial disease of the ocular surface, DED’s causes are not fully understood—but its impact on quality of life has proven to be substantial.
Furthermore: There are several known risk factors for DED, including medical conditions and medications, as well as environmental factors, age, and sex.
Now, talk about the study.
This large, cross-sectional study assessed DED using the Women’s Health Study (WHS) DED questionnaire and assessed personality using an abbreviated NEO Personality Inventory.
The personality domains assessed included:
- Neuroticism: “a tendency towards negative emotions with high vulnerability to stress and high emotional reactivity”
- Extraversion: “a high positive affect attained from external situations, excitement seeking, and emotional warmth”
- Conscientiousness: “having self-discipline, order, cautiousness, and being goal oriented”
Wait—What’s the NEO Personality Inventory?
The Revised NEO Personality Inventory (NEO-PI-R) is a personality test originally developed in 1978 by Paul Costa and Robert McCrae.
The test assesses the “Big Five” personality traits—the three mentioned above and two more:
- Agreeableness
- Openness to experience
Note: The NEO-PI-R has, of course, received its share of critique—for being too market-oriented, for poorly controlling for bias, and for being too complex—but its supporters argue that the assessment is both reliable and generalizable.
Ok, got it. Back to this study—who was included?
The study focused on 78,610 participants from the Lifelines cohort—a multi-disciplinary, prospective, population-based cohort study comprising of 167,729 people living in the northern Netherlands.
Participants (aged 18 to 64) completed the initial personality assessment between 2007 and 2013, and returned for dry eye assessment between 2014 and 2017.
The overall prevalence of DED in the cohort was 8.7%. The patient population consisted of:
- 40.2% male
- 59.8% female
- 48.7 average age
- 88.6% possessing at least one comorbidity (including but not limited to contact lens wear, asthma, Graves’ disease, and keratoconus)
So what did they find?
Higher neuroticism and lower conscientiousness were associated with higher rates of DED. Specifically:
- Higher levels of neuroticism
- DED odds ratio (OR): 1.10
- Highly symptomatic DED OR: 1.23
- Lower levels of conscientiousness
- DED OR: 0.97
- Highly symptomatic DED OR: 0.9
Tell me more.
The study results were split into three models:
- Model 1: Corrected for age and sex
- Model 2: Corrected for age, sex, body mass index, smoking status, education level, and net monthly household income
- Model 3: Corrected for age, sex, physical activity score, body mass index, smoking status, education level, net monthly household income, and 48 comorbidities associated with DED
The study found that across all models, “people with DED, and especially those with a high current symptom burden, had substantially higher neuroticism and lower conscientiousness domain scores than those without DED.”
And what does this mean?
According to investigators, “higher neuroticism and lower conscientiousness scores are tied to an increased prevalence of many diseases and conditions including depression, heart disease, hypertension, and osteoarthritis”—which are themselves associated with higher levels of DED.
So does higher neuroticism lead to increased risk of DED—or vice versa?
Well, that’s an acknowledged limitation of the study—a cohort study can’t show causality.
“More research is needed to determine the role of considering a patient's personality in the management of DED, and if clinicians should consider a structured mapping of personality, and potential targeted treatments such as supportive therapy or cognitive behavioral therapy, in patients not responding to standard DED treatment,” the investigators urged.
Expert opinion?
The study authors concluded that “using a framework incorporating the Big Five personality traits may improve treatment decisions and enhance the efficacy of interventions.”An example of this: Patients with higher neuroticism are more likely to prefer that healthcare personnel make treatment decisions, compared to selecting between different treatment options themselves, according to the authors.
Take home.
Lifestyle and environmental factors are already known aspects in dry eye diagnosis and treatment.
Assessing patient personality—and its potential impact on treatment adherence—is another tool for clinicians considering the psychological aspects of DED care.