A study conducted at the Faculty of Medicine of the University of São Paulo (USP) in Brazil examined the influence of personality traits on the development and perpetuation of insomnia and found that there is a direct relationship between the two. Two findings caught the researchers' attention: high levels of openness were associated with low levels of insomnia, while high levels of neuroticism (characterized by emotional instability) were very common in people with the sleep disorder. The results were published in the Journal of Sleep Research.
"We decided to study the influence of personality traits on insomnia because it's an extremely common disorder that has negative health consequences, such as an increased risk of hypertension, diabetes, anxiety and depression. These different physical and mental health conditions lead to a poorer quality of life in general," explains Bárbara Araújo Conway , sleep psychologist and author of the master's dissertation defended at the Institute of Psychiatry of FM-USP, with the support of FAPESP and under the supervision of Professor Renatha El Rafihi-Ferreira , of the Department of Clinical Psychology.
As the authors explain, insomnia is one of the most common sleep disorders in adults. It is estimated that around 30% of the world's population suffers from the problem, which is characterized by difficulty falling asleep, staying asleep or returning to sleep after an unwanted awakening. In Brazil, specifically in the city of São Paulo, this figure is even higher: almost half of the population (45%) suffers from insomnia, according to data from the Epidemiological Sleep Study ( EPISONO ).
Five personality traits
According to Conway, there is a well-established theory in the literature that proposes the existence of the "3 Ps" of insomnia: predisposition (factors that make an individual more likely to have the disorder), precipitation (triggers associated with the onset of symptoms) and perpetuation (behaviors that cause the person to remain in the vicious cycle of insomnia).
Thus, the researchers hypothesized that neuroticism, which is more prevalent in insomniacs, could be considered a predisposing factor for sleep disorders. They also examined whether symptoms of anxiety and depression might act as mediators and moderators of the association between neuroticism and insomnia.
But to understand how the authors arrived at the results of the study, we need to take a step back and learn about personality traits. "These are characteristics that estimate a pattern of what a particular person's feelings, thoughts and behaviors are like. They're a set of factors that make up an individual's personality and characteristics. According to the Big Five theory, we all have different levels of the five personality traits," the psychologist explained. They are:
1 – Extroversion: People with higher levels of extroversion tend to be more talkative, more dominant, with a leadership profile. They prefer group activities, find it easier to relate and create intimacy and tend to be more assertive. People with low levels of extroversion, on the other hand, are not necessarily introverts, but they prefer to be more alone and tend to find it more difficult to work in groups.
2 – Neuroticism: This is a personality trait related to the degree of emotional stability. People with high levels of neuroticism tend to be more emotionally unstable and focus on the more negative aspects of life. They are people who, when faced with adversity, tend to become disorganized, suffer more intensely, and are more susceptible to stress. Scientific literature shows that high neuroticism correlates with anxiety and depression.
3 – Agreeableness: This is a personality trait related to empathy. People with high levels of agreeableness tend to be more empathetic, more cordial and concerned about the well-being of others, focusing a lot on the other person's situation (they may even be naive and value the other person to the detriment of themselves). Those with low scores tend to be more skeptical and suspicious.
4 – Openness to experience: People who are open to new experiences tend to be more creative, with exploratory behavior in the face of novelty. They are curious, imaginative and experience emotions more intensely. People with low levels of openness are those who prefer routine, avoid discomfort and tend to be conventional.
5 – Conscientiousness: This can also be called achievement. People with high levels are determined, committed, motivated, persevering and can sacrifice momentary pleasures in pursuit of a greater goal. A very high index may not be good because it can lead to perfectionism. Those with low scores are less demanding, less stubborn, and would be considered "lazy" in the common sense of the word.
The study
To arrive at the results, the researchers studied 595 participants between the ages of 18 and 59, divided into two groups: one made up of insomniacs who had sought help and received a formal diagnosis from a sleep specialist, and the other half was a control group of people who had no complaints of insomnia.
Each participant's personality levels were determined using a 60-question, score-based questionnaire used exclusively by psychology professionals. Volunteers from both groups answered the questions, allowing the researchers to determine the scores for each person's personality traits.
After applying the questionnaire to the two groups, cross-checking and analyzing the data, Conway found that the insomnia patients had much higher scores for neuroticism than the non-insomnia subjects, as well as lower scores for agreeableness, openness and conscientiousness. Extroversion was the only personality trait that did not show a significant difference. "Neuroticism was the trait that stood out the most, with insomniacs having a much higher rate. But we can't say that insomniacs are more introverted," Conway ponders.
The analyses also showed that: 61.7% of the insomniacs had high levels of neuroticism compared to 32% of the control group; 40.7% of the insomniacs had low levels of openness compared to 23% of the healthy group; 31.5% of the subjects with insomnia had low levels of agreeableness compared to 23.2% of the non-insomniacs; and 37.7% of the insomniacs had low levels of conscientiousness compared to 24.1% of the control group.
"After more detailed statistical analysis, the results of the study allow us to assert that people with high levels of neuroticism are more likely to have insomnia," says the researcher.
The group also carried out a statistical analysis to see if any other factor might be confounding the association between neuroticism and insomnia, and discovered that anxiety acts as a mediating mechanism, meaning that it is the symptoms of anxiety that actually cause neuroticism to influence the development of insomnia. "It explains the whole effect of high neuroticism on insomnia," says the researcher. The group also tested the role of depression, but it did not prove to be an important mechanism in this relationship.
Effect on practice
Considering that personality traits are associated with positive or negative physical and mental health outcomes, the study suggests that it is important to know the most prevalent personality traits among individuals with insomnia so that this knowledge can help in the process of assessment, prevention and planning of more appropriate treatments according to the specific characteristics of each patient.
The results confirm that in order to treat a patient's insomnia, it is also necessary to assess and treat their anxiety. "These findings are important in clinical practice because when receiving patients with this personality trait, it's essential to think about a treatment plan that focuses not only on sleep but also on anxiety," says El Rafihi-Ferreira.
But for this to happen, healthcare professionals need to understand and assess the personalities of patients who seek help for sleep problems. "We know that most insomniacs are highly neurotic. These patients deserve to have their anxiety assessed and treated so that their insomnia also improves. Sometimes this involves different therapies and medications, so it's important to take a broader look at each individual's history and specifics," Conway emphasizes.
Currently, the treatment considered the "gold standard" for insomnia is cognitive-behavioral therapy for insomnia (CBT-I), but there are still too few psychologists specializing in sleep in Brazil to offer it. For this reason, the researchers advocate that health professionals take a broader view and delve deeper into the study of patients' psychological factors.
"The association between personality traits, anxiety and insomnia makes it important to develop transdiagnostic treatment protocols, i.e. those that involve the integration of behavioral techniques and processes to treat a range of emotional difficulties that share processes and mechanisms underlying the different complaints," says the study's supervisor.
"We already have a non-pharmacological treatment for insomnia, but just as we don't have a drug that will be effective for all patients, a single therapy approach may not work for everyone. These results contribute to the development of new, more personalized psychological and behavioral protocols for the treatment of insomnia," Conway concludes.
About FAPESP
The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the state of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration.
