Somnologie 2013 · 17:281–283DOI 10.1007/s11818-013-0623-zReceived: 21 June 2013Accepted: 27 September 2013Published online: 26 October 2013© Springer-Verlag Berlin Heidelberg 2013

J. Steinig1, 2 · T. Reess1 · G. Klösch3 · C. Sauter3, 4 · J. Zeitlhofer3 · S. Happe1, 5

1 Department of Clinical Neurophysiology, Klinikum Bremen-Ost/University of Göttingen2 Department of Psychosomatic Medicine, University of Leipzig3 Department of Neurology, Medical University of Vienna4 Competence Center of Sleep Medicine CC15, Charité, University Medicine Berlin, Campus Benjamin Franklin, Berlin5 Department of Neurology, Klinik Maria Frieden Telgte

Personality traits in patients with restless legs syndrome

Restless legs syndrome (RLS) is one of the most common neurological disorders. It is associated with reduced sleep quality, im-paired cognitive function, mood distur-bances, and reduced quality of life. In ad-dition, the prevalence of depressive symp-toms and anxiety has been found to be in-creased [1]. However, most studies did not consider specific personality characteris-tics of RLS patients although they might have a crucial influence on the mental state of the patients and the progress of the complaints. Only one previous study [2] found that RLS was associated with high-er neuroticism symptoms.

The aim of this study was to compare de novo RLS patients with age- and sex-matched healthy controls in view of per-sonality traits, depression, and anxiety.

Methods

In all, 30 consecutive patients with idiopath-ic RLS (9 male, mean age 57.6±12.6 years, duration of disease 9.0±11.0 years) were di-agnosed according to the established diag-nostic criteria in a face-to-face interview and investigated by an expert at the sleep disorders clinics, Department of Neurolo-gy, University Hospital of Vienna [3, 4]. Pa-tients were only included if they were de novo and without relevant medication in-fluencing RLS symptoms and sleep. Sever-ity of symptoms was assessed with the RLS severity scale [5]. Mean score was 16.1±3.5,

corresponding to moderate symptoms. The control group (n=30) was age and sex adjusted. Sleep disorders, depression, and anxiety disorders were exclusion criteria for the control group as determined in a clinical interview.

Participants were asked to complete the NEO Five-Factor Inventory (NEO-FFI) [6] which is designed to measure five do-mains of personality: “neuroticism”, “extra-version”, “openness to experience”, “agree-ableness”, and “conscientiousness”. NEO-FFI scores were standardized by convert-ing raw scores to T-scores using means and standard deviations of men and women from an external general population sam-ple (mean 50, SD 10). Most of the factor-level mean scores in the RLS sample and non-RLS controls fell within the average range (T-score between 40 and 55).

The Self-Rating Depression Scale (SDS) [7] is a one-dimensional self-report ques-tionnaire which covers affective, psycho-logical, and somatic symptoms associat-ed with depression. Likewise, the Self-Rat-ing Anxiety Scale (SAS) [8] evaluates anx-iety-associated symptoms. All participants also completed the Pittsburgh Sleep Qual-ity Index (PSQI) [9] which assesses subjec-tive sleep quality of the preceding 4 weeks. All patients gave informed consent; inclu-sion of patients was approved by the ethics committee, University of Vienna.

All questionnaire scores as well as per-sonality factors were compared using t-

tests. Potential effects of sex or age were adjusted by using t-tests based on norms, taking into account gender and age. Bon-ferroni correction was used to adjust for multiple testing. Significance level was set at α=0.05.

Results

RLS patients scored significantly high-er on the SDS than did the control sub-jects (p<0.001). In all, 36.7% of RLS pa-tients showed higher values than the cut-off score of 40 and, therefore, revealed symptoms of clinically relevant depres-sion, whereas none of the control subjects scored higher than 40.

Patients scored also significantly high-er on the SAS (p<0.001) with 43.3% high-er than one standard deviation above the mean value of control values and anoth-er 43.3% higher than two standard devia-tions above control values. Patients had a mean total score slightly above the cut-off score of 36 (37.4±4.9). There were no gen-der differences in the SDS or the SAS to-tal scores, neither for the patients, nor for the controls.

Sleep quality was significantly im-paired in RLS patients: all patients scored higher than 5 in the PSQI, the cut-off score for sleep disorders, with a mean of 12.8±3.4 as compared to 3.6±1.1 in the con-trol group (p<0.001).

281Somnologie 4 · 2013  | 

Schwerpunkt

In the NEO-FFI, patients exhibited sig-nificantly higher t-scores on the subscale

“neuroticism” (p<0.001). In addition, they scored significantly lower on the subscales

“openness to experience” (p=0.007), and “agreeableness” (p=0.017) as compared to the healthy controls. However, the latter result was not statistically significant af-ter Bonferroni correction. Besides one ex-ception (extraversion in the control group, p=0.046), there were no gender differenc-es in the NEO-FFI subscales. The total scores of the SDS, SAS, and PSQI as well as the t-scores of the five subscales of the NEO-FFI are shown in . Tab. 1.

Discussion

Compared to healthy controls, patients with de novo RLS tend to report more de-pressive and anxiety-associated symptoms and suffer from impaired sleep. RLS pa-tients also show significantly higher scores for “neuroticism”, being in line with one previous study investigating personality traits in RLS [2].

According to this, RLS patients are emotionally less stable, experience more negative emotions, and tend to get out of mental balance more easily. They are more nervous, anxious, insecure, and less confident. This could be ascribed to the fact that most RLS patients suffer from their symptoms for a long time before finding adequate treatment which is of-ten accompanied by feelings of helpless-ness and hopelessness.

Additionally, we found for the first time a significantly lower score of the

RLS patients on the subscale “openness to experience”. This might express a rath-er diminished interest in novelty and va-riety and hint at a more conservative, re-served, and reticent attitude. Since many patients suffering from RLS established a daily routine helping them to cope with their symptoms, which strongly affects their private and social life, it seems likely that they are attached to familiar routine and activities and avoid new experiences.

As Kalaydijan et al. [2] claim, high neuroticism, and following our results low openness to experience as well, might be discussed as predisposing factors for the development of RLS. In both stud-ies, the NEO-FFI scores were compara-ble and within the normative data [6], not only in the control group but also in the patient group. However, normative data were collected in the German capital Ber-lin with a different historical and cultural background than our sample from Vien-na. Therefore, we believe that the norma-tive data [6] do not necessarily apply com-pletely to our sample. In addition, in our sample more women than men were in-cluded as compared to the normative da-ta. Since it has been shown that sex influ-ences personality traits [6], this might be another reason why the normative data do not fully apply to our sample. These were the reasons why we decided to com-pare our data to a matched own control group with the result that RLS patients show higher scores for “neuroticism” and lower scores for “openness to experience”.

The central dopaminergic system, as well as the central serotonergic system,

has been reported to be correlated with higher neuroticism. Recent data suggest that genes affecting the dopamine sys-tem are involved in the development of personality traits and contribute to edu-cational attainment [10]. In addition, the variability in dopamine stress response seems to be related to individual differ-ences in personality [11], and the striatal dopamine D2 receptor densities were sig-nificantly correlated with the neuroticism score [12]. Therefore, the central dopami-nergic system may play an important role in the neurobiological characteristics of neuroticism and this might be a link be-tween RLS, neuroticism, and the dopami-nergic system.

Summarizing, de novo, unmedicat-ed RLS patients seem to be more worried, nervous, and discontent compared to healthy controls. They are more easily ir-ritable and more vulnerable to stress. They also tend to withdraw from social con-tacts and rather occupy themselves with their symptoms. The question whether these differences in personality traits are cause or consequence of the RLS needs further investigation in a larger number of patients in a longitudinal study.

Corresponding address

Prof. Dr. S. HappeDepartment of Neurology,  Klinik Maria Frieden TelgteAm Krankenhaus 1, 48321 TelgteGermanyshappe@gwdg.de

Acknowledgment.  The authors thank Karin Mayer for contacting patients and help in acquisition of data.

Compliance with ethical guidelines

Conflict of interest.  J. Steinig, T. Reess, G. Klösch, C. Sauter, J. Zeitlhofer, and S. Happe state that there are no conflicts of interest.

All studies on humans described in the present man-uscript were carried out with the approval of the re-sponsible ethics committee and in accordance with national law and the Helsinki Declaration of 1975 (in its current, revised form). Informed consent was obtained from all patients included in studies.

Tab. 1  Mean scores ± standard deviations of depression (SDS) and anxiety (SAS) scales, Pittsburgh Sleep Quality Index (PSQI) as well as personality factors (NEO-FFI) of restless legs syndrome (RLS) patients and healthy controls

  RLS patients Healthy controls p value

(n=30) (n=30)

SDS (total score) 39.9±7.4 28.8±8.6 <0.001

SAS (total score) 37.4±4.9 26.0±4.3 <0.001

PSQI (total score) 12.8±3.4 3.6±1.1 <0.001

Personality factors (t-scores)     p valuea

Neuroticism 52.3±8.4 41.6±9.0 <0.001

Extraversion 47.9±9.0 51.9±11.2 0.144

Openness 45.3±6.9 51.9±10.5 0.007

Agreeableness 48.6±11.5 55.5±9.6 0.017

Conscientiousness 55.4±9.3 52.7±10.8 0.317ap values still displaying significant differences after Bonferroni correction within the t-scores of the personality factors are in bold.

282 |  Somnologie 4 · 2013

Schwerpunkt

References

  1.  Winkelmann J, Prager M, Lieb R et al (2005) “Anx-ietas tibiarum”. Depression and anxiety disorders in patients with restless legs syndrome. J Neurol 252:67–71

  2.  Kalaydjian A, Bienvenu OJ, Henning WA et al (2009) Restless legs syndrome and the five-factor model of personality: results from a community sample. Sleep Med 10:672–675

  3.  Walters AS (1995) Toward a better definition of the restless legs syndrome. The International Restless Legs Syndrome Study Group. Mov Disord 10:634–642

  4.  Allen RP, Picchietti D, Hening WA et al (2003) Rest-less legs syndrome: diagnostic criteria, special con-siderations and epidemiology. A report from the restless legs syndrome diagnosis and epidemiol-ogy workshop at the National Institutes of Health. Sleep Med 4:101–119

  5.  Becker PM, Ondo W, Sharon D (1998) Encouraging initial response of restless legs syndrome to prami-pexole. Neurology 51:1221–1223

  6.  Borkenau P, Ostendorf F (1993) NEO-Fünf-Faktoren Inventar (NEO-FFI) nach Costa und Mc Crae. Han-danweisung. Hogrefe, Göttingen

  7.  Zung WWK (1965) A self-rating depression scale. Arch Gen Psychol 12:63–70

  8.  Zung WWK (1971) A rating instrument for anxiety disorders. Psychosomatics 12:371–379

  9.  Buysse DJ, Reynolds CF 3rd, Monk TH et al (1989) The Pittsburgh sleep quality index: a new instru-ment for psychiatric practice and research. Psychi-atry Res 28:193–213

10.  Lehto K, Akkermann K, Parikh J et al (2013) Effect of COMT Val158Met polymorphism on personali-ty traits and educational attainment in a longitudi-nal population representative study. Eur Psychiatry pii: S0924–9338(13)00082–5. doi:10.1016/j.eurp-sy.2013.06.008. (Epub ahead of print)

11.  Suridjan I, Boileau I, Bagby M et al (2012) Dopa-mine response to psychosocial stress in humans and its relationship to individual differences in per-sonality traits. J Psychiatr Res 46:890–897

12.  Lee IH, Cheng CC, Yang YK et al (2005) Correlation between striatal dopamine D2 receptor density and neuroticism in community volunteers. Psychi-atry Res 138:259–264

Abstract · Zusammenfassung

Somnologie 2013 · 17:281–283   DOI 10.1007/s11818-013-0623-z© Springer-Verlag Berlin Heidelberg 2013

J. Steinig · T. Reess · G. Klösch · C. Sauter · J. Zeitlhofer · S. HappePersonality traits in patients with restless legs syndrome

AbstractObjective.  In restless legs syndrome (RLS), the prevalence of depressive symptoms and anxiety has been found to be increased. How-ever, most studies did not consider specif-ic personality characteristics of patients al-though they might have a crucial influence on the mental state of the patient. The aim of this study was to compare RLS patients with healthy controls in view of personality traits, depression, and anxiety.Methods.  In all, 30 consecutive patients with idiopathic RLS (de novo) were compared to 30 age- and sex-matched healthy controls. The severity of symptoms was assessed us-ing the RLS severity scale. Sleep disorders, depression, and anxiety disorders were ex-clusion criteria for the control group. Partici-pants were asked to fill in the NEO Five-Fac-tor Inventory (NEO-FFI) to assess personal-ity traits, as well as the Self-Rating Depres-sion Scale (SDS) and the Self-Rating Anxiety Scale (SAS).Results.  RLS patients scored significant-ly higher on the SDS (39.0±7.4 vs. 28.8±5.7, 

p<0.001) as well as the SAS (37.4±4.9 vs. 26.0±4.3, p<0.001) compared to the con-trol group. In the NEO-FFI, patients exhib-ited significantly higher scores on the sub-scale “neuroticism” (52.3±8.4 vs. 41.6±9.0, p<0.001). In addition, they scored significant-ly lower on the subscales “openness to expe-rience” (45.3±6.9 vs. 51.9±10.5, p=0.007) and showed a trend in “agreeableness” (48.6±11.5 vs. 55.5±9.6, p=0.017; ns after Bonferroni cor-rection) compared to healthy controls.Discussion.  RLS patients seem to be more worried, nervous, and discontent. They are more easily irritable and more vulnerable to stress. They also tend to withdraw from social contacts and rather occupy themselves with their symptoms.

KeywordsSelf-Rating Depression Scale · Self-Rating Anxiety Scale · Depression · Anxiety · NEO Five-Factor Inventory

Persönlichkeitsmerkmale bei Patienten mit Restless-Legs-Syndrom

ZusammenfassungZiel.  Die Prävalenz von depressiven und Angstsymptomen ist beim Restless-Legs-Syn-drom (RLS) erhöht. Die spezifische Persön-lichkeit wurde jedoch in den meisten Studi-en nicht berücksichtigt, obwohl sie einen er-heblichen Einfluss auf die psychische Verfas-sung haben kann. Ziel dieser Studie war es daher, Persönlichkeitsmerkmale, Depression und Angst von RLS-Patienten im Vergleich zu Gesunden zu untersuchen.Patienten und Methoden.  Dreißig konseku-tive Patienten mit idiopathischem RLS (de no-vo) wurden mit 30 alters- und geschlechts-gleichen gesunden Kontrollen verglichen. Der Schweregrad des RLS wurde mit der RLS-Schweregradskala gemessen. Schlafstörun-gen, Depression und Angststörungen waren Ausschlussmerkmale bei den Kontrollen.  Alle Teilnehmer füllten das NEO-5-Faktoren-Inventar (NEO-FFI) aus, um die Persönlich-keitsmerkmale darzustellen, außerdem die Self-Rating Depression Scale (SDS) und die Self-Rating Anxiety Scale (SAS).Ergebnisse.  RLS-Patienten hatten signifi-kant höhere Werte in der SDS (39,0±7,4 vs. 

28,8±5,7; p<0,001) und in der SAS (37,4±4,9 vs. 26,0±4,3; p<0,001). Im NEO-FFI zeig-ten die Patienten signifikant höhere Werte in der Subskala „Neurotizismus“ (52,3±8,4 vs. 41,6±9,0; p<0,001). Außerdem zeigten sie signifikant niedrigere Werte in den Sub-skalen „Offenheit für Erfahrung“ (45,3±6,9 vs. 51,9±10,5; p=0,007) und zeigten einen Trend für „Verträglichkeit“ (48,6±11,5 vs. 55,5±9,6; p=0,017; nichtsignifikant nach Bonferro-ni-Korrektur) im Vergleich zu den gesunden Kontrollen.Diskussion.  RLS-Patienten scheinen ängst-licher, nervöser und unzufriedener zu sein. Sie sind leichter irritierbar und anfälliger für Stress. Sie tendieren außerdem dazu, vor so-zialen Kontakten zurückzuschrecken und be-schäftigen sich vermehrt mit ihren Symp-tomen.

SchlüsselwörterSelf-Rating Depression Scale · Self-Rating Anxiety Scale · Depression · Angst · NEO-5-Faktoren-Inventar

283Somnologie 4 · 2013  |