Influence of personality on sexual quality of life in epilepsy

ARTICLE

Auteur(s) : Daniela Mölleken¹, Hertha Richter-Appelt², Stefan Stodieck¹, Thomas Bengner³

¹Epilepsy Center Hamburg, Protestant Hospital Alsterdorf, Hamburg
²Institute for Sexual Research and Forensic Psychiatry, University Clinic Eppendorf, University of Hamburg
³Charité, Campus Mitte, Department of Psychiatry and Psychotherapy, Berlin, Germany

Article reçu le 12 Decembre 2009, accepté le 26 Avril 2010

Epilepsy is associated with an increased rate of sexual dysfunction in women and men (Morrell et al., 1994; Morrell and Guldner, 1996; Herzog et al., 2005). The aetiology of sexual dysfunction in epilepsy is probably multifactorial (Morrell, 1991), based on endocrinological, neurological, pharmacological, psychological, and social factors (Baird et al., 2003; Devinsky, 2005; De Souza et al., 2000; Morrell et al., 2005; Harden, 2002; Lambert, 2001). While endocrinological and pharmaceutical correlates have frequently been studied, studies focusing on psychological influences are far less reported (Talbot et al., 2008). The present study investigated the influence of personality on sexual dysfunction in epilepsy patients.

The term “sexual dysfunction” may refer to different aspects such as erectile dysfunction or decrease in libido. In the present study we documented sexual well-being using a comprehensive questionnaire covering several sexual functions and aspects in women and men (Derogatis et al., 1991; Derogatis, 1997). We have used the term sexual quality of life (SQOL) (Arrington et al., 2004) which encompasses five to six different domains which include: (a) interest, desire, and libido, (b) satisfaction with or quality of sexual experiences such as ejaculation or orgasm and pain or discomfort with sex, (c) sufficient excitement and arousal, for example, as shown by sufficient erection or lubrication for intercourse, (d) the ability to achieve an orgasm, (e) attitudes or behaviours, for example, feelings of avoidance or embarrassment and fluctuation in the frequency of sexual intercourse, and (f) the impact of sexual functioning on the relationship (Derogatis, 1997; Arrington et al., 2004).

Personality has an influence on quality of life in healthy adults (Ramanaiah et al., 1997). An influential model of personality is the five-factor model (e.g. Costa and McCrae, 1992) which distinguishes between openness to new experiences, conscientiousness, extraversion, agreeableness, and neuroticism. Epilepsy is often related to accentuated personality traits (Rose et al., 1996), and a substantial number of epilepsy patients suffer from low quality of life. Thus, personality changes due to epilepsy may have a negative impact on the patient's quality of life. For example, increased neuroticism in epilepsy patients correlates with depression and anxiety and is inversely related to quality of life (Swinkels et al., 2003). Moreover, low quality of life and depression (with or without antidepressant medication) is frequently related to decreased libido (Mathew and Weinman, 1982). Accordingly, epilepsy patients with symptoms of depression and anxiety frequently also suffer from sexual dysfunction (De Souza et al., 2000; Morrell et al., 2005; Talbot et al., 2008). In the present study, we hypothesized that accentuated personality traits in epilepsy patients may have a negative influence on their SQOL.

It is known that certain personality traits may have a positive or negative influence on sexual quality of life. For example, in patients with sexual problems, elevated neuroticism is correlated with dysphoric symptoms, negative body image, and lowered sexual satisfaction. On the other hand, more extraverted patients with sexual problems report more sexual drive and experience a more positive body image, and more positive affects in relation to sexuality than patients with low extraversion (Costa et al., 1992). Furthermore, openness to new experiences is positively correlated with the range of sexual experiences, a liberal attitude towards sex, and sexual drive and fantasy (Costa et al., 1992). In the present study we hypothesised that while extraversion and openness could have a positive effect, neuroticism could have a negative effect on SQOL in epilepsy patients.

SQOL and its determinants may differ between the sexes. Interestingly, sexual dysfunction is related to psychological and social problems in women, but to self-reported physical problems in men (Harris et al., 2008; Dunn et al., 1999). In order to study SQOL in both women and men with epilepsy, the DISF-SR (Derogatis et al., 1991; Derogatis, 1997; Derogatis, 1996) was selected as a questionnaire to determine sexual quality of life. This inventory includes almost identical versions for women and men, but at the same time still carefully considers important differences between the sexes in relation to arousal and orgasm.

Methods

Patients

Procedures

Of the remaining 137 patients, we further excluded 88 patients based on the following (many patients had two or more reasons leading to their exclusion): 48 patients had a psychiatric co-morbidity other than self-reported depression or anxiety disorder (mostly substance abuse or alcohol abuse); patients with organic amnesic syndrome were also excluded, as we felt that these patients may not have been able to reflect on their past experiences well enough to fill out the questionnaires validly; 23 patients had a neurological co-morbidity other than epilepsy (e.g. severe head injury, stroke); 14 patients had internal co-morbidities (e.g. urological diagnoses, thyroid disease, heart disease); 13 patients received a primary diagnosis other than epilepsy (e.g. sleep disturbance, syncope due to non-neurological reasons); 12 epilepsy patients took enzyme-inducing antiepileptic drugs known to influence SQOL (Mölleken et al., 2009). In addition, five patients otherwise suited to the study did not complete all three questionnaires relating to SQOL, life satisfaction, and personality (see below), and were thus also excluded. Patients received the questionnaires during the first three days of their stay, as the questionnaires related to the preceding four weeks.

Assessment of SQOL

Assessment of personality

Assessment of general life satisfaction, depression, and trait anxiety

Diagnostic work-up

Statistical methods

Results

To test the hypothesis of the present study, i.e. whether personality traits influence SQOL in epilepsy patients, we calculated a regression analysis with the DISF-SR overall score as the dependent variable, and the five personality factor scores, sex, and the life satisfaction score as independent variables (n = 49). DISF-SR overall T-score was predicted by sex (t (46) = - 2.7, beta = - 0.36, p = 0.007) and the T-score for extraversion (t (46) = 3.1, beta = 0.39, p = 0.003). This model explained 22% of the variance (corrected R² = 0.22, F (2,46) = 7.8, p = 0.001). The effect of extraversion on DISF-SR overall T-score is illustrated in figure 1. When using raw scores from the questionnaires instead of the norm scores, we received a very similar result. DISF-SR overall raw score was predicted by sex (t (46) = - 3.9, beta = - 0.48, p < 0.001) and extraversion (t (46) = 3.0, beta = 0.37, p = 0.004). The model explained 29% of the variance (corrected R² = 0.29, F (2,46) = 10.7, p < 0.001).

We subsequently explored the more fine-grained influence of sex, the five personality factors, and life satisfaction on the different SQOL sub-scales. We calculated five regression analyses with the different DISF-SR sub-scores as the dependent variable, and the five personality factor scores, sex, and the life satisfaction score as independent variables (n = 49). Employing the norms scores, we obtained the following results:

1) DISF-SR fantasy was predicted by sex (t (45) = - 3.6, beta = - 0.44, p < 0.001), extraversion (t (45) = 3.7, beta = 0.46, p < 0.001), and conscientiousness (t (45) = - 2.2, beta = - 0.28, p = 0.03). The model explained 31% of variance (corrected R², F (3,45) = 8.1, p < 0.001);

2) DISF-SR arousal was predicted by sex (t (47) = - 3.0, beta = - 0.40, p = 0.003). The model explained 15% of variance (corrected R², F (1,47) = 9.2, p = 0.004);

3) DISF-SR experience was predicted by extraversion (t (47) = 2.9, beta = 0.39, p = 0.006). The model explained 13% of variance (corrected R², F (1,47) = 8.2, p = 0.006);

4) DISF-SR orgasm was predicted by sex (t (45) = - 2.4, beta = - 0.32, p < 0.02), agreeableness (t (45) = - 2.8, beta = - 0.41, p = 0.006), and life satisfaction (t (45) = 3.4, beta = 0.49, p = 0.001). The model explained 21% of variance (corrected R², F (3,45) = 5.3, p = 0.003);

5) DISF-SR drive was predicted by sex (t (44) = - 3.2, beta = - 0.43, p = 0.003), agreeableness (t (44) = - 2.6, beta = - 0.36, p = 0.01), conscientiousness (t (44) = - 1.9, beta = - 0.27, p = 0.06), and life satisfaction (t (44) = 4.0, beta = 0.62, p < 0.001). The model explained 25% of variance (corrected R², F (4,44) = 5.0, p = 0.002).

We also re-calculated the five latter analyses with raw scores instead of norm scores. This lead to very similar results when the identical variables were included in the respective regression models, and only minor changes in the beta scores, or the amount of variance explained by the models. It is important to note that we did not correct these post-hoc analyses for multiple significance tests, and the alpha error of the reported significances may thus be inflated. However, the resulting regression models remain significant even when the significance level was raised to p < 0.01.

As a side result of the present study, we further tested correlations between the five personality factors and life satisfaction in our patient sample (n = 49). Using raw scores, life satisfaction correlated negatively with neuroticism (r = - 0.58; p < 0.001), and positively with extraversion (r = 0.57; p < 0.001), agreeableness (r = 0.44; p = 0.04), and conscientiousness (r = 0.40; p = 0.04).
Table 1 Demographic and clinical description of the patient sample.

Discussion

To our knowledge, the negative influence of low extraversion on SQOL has not previously been reported in epilepsy patients. In our study, extraversion was related to the frequency of sexual fantasies and sexual experiences, and to overall SQOL. In an earlier study in patients with sexual problems but without epilepsy, higher extraversion was related to increased drive, more sexual experience, a positive body image, and more positive affects in relation to sexuality (Costa et al., 1992). The effect of extraversion on the frequency of sexual experiences found in this earlier study has therefore been replicated in our study. In addition, we observed that extraversion was only moderately decreased in men and women with epilepsy when compared with the norm value, as provided by the NEO-FFI manual. Future studies should analyse causes of lower extraversion in epilepsy. We also found low openness to new experiences and high neuroticism in epilepsy patients. However, in contrast to an earlier study, we found no correlation with overall SQOL (Costa et al., 1992).

In the present study, women with epilepsy had less frequent sexual fantasies and sexual arousal, lower orgasm quality, and lower sexual drive than men with epilepsy. The effect of sex on SQOL in epilepsy in the present paper became evident based on both raw scores and gender-keyed norm scores. Moreover, lower DISF-SR scores were reported for women than men with epilepsy, again visible in all raw and norm scores. Also, the DISF-SR overall score of women was one standard deviation below the expected mean as provided by the test manual, while men showed normal SQOL. Thus, although the DISF-SR versions for men and women may differ in some respects, the lower SQOL we report for women cannot be attributed to the differences in the inventories for women and men in some of the sub-scales (see “methods” section). Also, the lower DISF-SR overall score in women is not explained by more severe depression or lower life satisfaction in women than in men with epilepsy. We conclude that women with epilepsy have a decreased SQOL compared to the expected SQOL in healthy women (table 2) and in comparison to men with epilepsy. To our knowledge, this is the first study to directly compare SQOL in women and men. However, future studies comparing SQOL in women and men with epilepsy should include healthy participants in their analysis, to further validate this interpretation.

In contrast to earlier studies (e.g. Herzog et al., 2005), we observed that men with epilepsy had normal SQOL. In a recent related paper, we reported that enzyme-inducing antiepileptic drugs negatively influence SQOL in men, but not in women (Mölleken et al., 2009). In the present study, we excluded twelve patients taking enzyme-inducing antiepileptic drugs and this may explain why we could not observe a decrease of SQOL in men, and may account for differences of SQOL in epilepsy reported elsewhere.

Based on the present study, we cannot determine whether the correlation between extraversion and SQOL is causal, or merely an association. For example, epilepsy and psychosocial responses to the disease may lead to reduced quality of life that in turn might result in a change of personality. However, former longitudinal studies on the influence of personality on quality of life in epilepsy patients were able to show a causal influence of pre-operative personality on post-operative psychosocial adjustment and health-related quality of life (Rose et al., 1996). Also, extraversion has been shown to be very stable throughout life (Srivastava et al., 2003). In contrast, sexual quality of life can be sensitive to changes in relation to life circumstances (Arrington et al., 2004). It is plausible therefore that this asymmetry of extraversion and SQOL reflects a causal influence of extraversion on SQOL in this study, and not vice versa.

As mentioned in the introduction, certain personality traits in epilepsy patients are associated with depression and anxiety (Swinkels et al., 2003). On the other hand, depression and anxiety are frequently associated with reduced sexual quality of life (De Souza et al., 2000; Morrell et al., 2005; Talbot et al., 2008). This raises the question as to whether personality is directly associated with SQOL or whether the reported association between extraversion and SQOL is mediated by depression and anxiety. The lack of significant depression and anxiety in our sample suggests that mediation is not the answer.

One theoretical implication of the present research is the need for future studies on SQOL in epilepsy to recognise the influence of extraversion and sex on SQOL. As a clinical implication, personality traits and especially extraversion should be investigated using appropriate questionnaires, together with inventories of sexual quality of life, especially for women with epilepsy. Furthermore, our results raise the possibility that decreased SQOL in epilepsy patients due to introversion may be overcome by strengthening self-confidence by means of social skills training in adolescents (e.g. Cheng and Furnham, 2002). Our research underlines the view that the decrease in SQOL in epilepsy is multifactorial and calls for a multidisciplinary approach to ensure appropriate treatment (Morrell, 1991; Harden, 2002; Talbot et al., 2008).

Disclosure

References

[Baird et al., 2003] Baird AD, Wilson SJ, Bladin PF, Saling MM, Reutens DC. Sexual outcome after epilepsy surgery. Epilepsy Behav 2003; 4: 268-78.

[Borkenau and Ostendorf, 1993] Borkenau P, Ostendorf F. NEO-Fünf-Faktoren Inventar (NEO-FFI). Göttingen: Hogrefe, 1993.

[Cheng and Furnham, 2002] Cheng H, Furnham A. Personality, peer relations, and self-confidence as predictors of happiness and loneliness. J Adolesc 2002; 25: 327-39.

[Costa and McCrae, 1992] Costa PT, McCrae RR. Revised NEO Personality Inventory (NEO-PI-R) and the Five Factor Inventory (NEO-FFI): professional manual. Odessa, Florida: Psychological Assessment Resources Inc, 1992.

[Costa et al., 1992] Costa PT, Fagan PJ, Piedmont RL, Ponticas Y, Wise TN. The five-factor model of personality and sexual functioning in outpatient men and women. Psychiatr Med 1992; 10: 199-215.

[Derogatis, 1996] Derogatis LR. Derogatis Interview For Sexual Functioning (DISF/DISF-SR). Baltimore, MD: Preliminary Scoring, Procedures & Administration Manual. Clinical Psychometric Research, 1996.

[Derogatis, 1997] Derogatis LR. The Derogatis Interview for Sexual Functioning (DISF/DISF-SR): an introductory report. J Sex Marital Ther 1997; 23: 291-304.

[Derogatis et al., 1991] Derogatis L, Meyer J, King KM. Psychopathology in individuals with sexual dysfunction. Am J Psychiatry 1991; 138: 757-62.

[De Souza et al., 2000] De Souza EAP, Keiralla DMB, Silveira DC, Guerriero CAM. Sexual dysfunction in epilepsy. Identifying the psychological variables. Arquivos Neuro-Psiquiatria 2000; 58: 214-20.

[Devinsky, 2005] Devinsky O. Neurologist-induced sexual dysfunction. Enzyme-inducing antiepileptic drugs. Neurology 2005; 65: 980-1.

[Dunn et al., 1999] Dunn KM, Croft PR, Hackett GI. Association of sexual problems with social, psychological, and physical problems in men and women: a cross sectional population survey. J Epidemiol Community Health 1999; 53: 144-8.

[Fahrenberg et al., 2000] Fahrenberg J, Myrtek M, Schumacher J, Brähler E. Fragebogen zur Lebenszufriedenheit. Göttingen: Hogrefe Verlag für Psychologie, 2000.

[Harris et al., 2008] Harris JM, Cherkas LF, Kato BS, Spector TD, Heiman JR. Normal variations in personality are associated with coital orgasmic infrequency in heterosexual women: A population-based study. J Sex Med 2008; 5: 1177-83.

[Harden, 2002] Harden CL. Treatment of sexual disorders in people with epilepsy. Epilepsy Behav 2002; 3: 38-41.

[Hautzinger et al., 1993] Hautzinger M, Bailer M, Worall H, Keller F. Beck-Depressions-Inventar, Manual. Bern: Huber Verlag, 1993.

[Herzog et al., 2005] Herzog AG, Drislane FW, Schomer DL, et al. Differential effects of antiepileptic drugs on sexual function and hormones in men with epilepsy. Neurology 2005; 65: 1016-20.

[Lambert, 2001] Lambert MV. Seizures, hormones and sexuality. Seizure 2001; 10: 319-40.

[Laux et al., 1981] Laux L, Glanzmann P, Schaffner P, Spielberger CD. STAI-deutsche Fassung. Göttingen: Manual. Beltz Test GmbH, 1981.

[Lüders et al., 1998] Lüders H, Acharya J, Baumgartner C, et al. Semiological seizure classification. Epilepsia 1998; 39: 1006-13.

[Manford, 2001] Manford M. Assessment and investigation of possible epileptic seizures. J Neurol Neurosurg Psychiatry 2001; 70 (Suppl. II): ii3-ii8.

[Mathew and Weinman, 1982] Mathew RJ, Weinman ML. Sexual dysfunction in depression. Arch Sex Behav 1982; 11: 323-8.

[Mölleken et al., 2009] Mölleken D, Richter-Appelt H, Stodieck S, Bengner T. Sexual quality of life in epilepsy: correlations with sex hormone blood levels. Epilepsy Behav 2009; 14: 226-31.

[Morrell, 1991] Morrell MJ. Sexual dysfunction in epilepsy. Epilepsia 1991; 32: 38-45.

[Morrell et al., 1994] Morrell MJ, Sperling MR, Stecker M, Dichter MA. Sexual dysfunction in partial epilepsy: a deficit in physiologic sexual arousal. Neurology 1994; 44: 243-7.

[Morrell and Guldner, 1996] Morrell MJ, Guldner GT. Self-reported sexual function and sexual arousability in women with epilepsy. Epilepsia 1996; 37: 1204-10.

[Morrell et al., 2005] Morrell MJ, Flynn KL, Done S, Flaster E, Kalayjian L, Pack AM. Sexual dysfunction, sex steroid abnormalities, and depression in women with epilepsy treated with antiepileptic drugs. Epilepsy Behav 2005; 6: 360-5.

[Ramanaiah et al., 1997] Ramanaiah NV, Detwiler FR, Byravan A. Life satisfaction and the five-factor model of personality. Psychol Rep 1997; 80: 1208-10.

[Rose et al., 1996] Rose KJ, Derry PA, McLachlan RS. Neuroticism in temporal lobe epilepsy: assessment and implications for pre- and postoperative psychosocial adjustment and health-related quality of life. Epilepsia 1996; 37: 484-91.

[Rosenow et al., 2001] Rosenow F, Hamer HM, Knake S, et al. Lateralizing and localizing signs and symptoms of epileptic seizures: Significance and application in clinical practice. Nervenarzt 2001; 72: 743-9.

[Schmidt and Metzler, 1992] Schmidt KH, Metzler P. Wortschatztest, Manual. Weinheim: Beltz, 1992.

[Srivastava et al., 2003] Srivastava S, John OP, Gosling SD, Potter J. Development of personality in early and middle adulthood: set like plaster or persistent change? J Pers Soc Psychol 2003; 84: 1041-53.

[Swinkels et al., 2003] Swinkels WAM, Duijsens IJ, Spinhoven PH. Personality disorder traits in patients with epilepsy. Seizure 2003; 12: 587-94.

[Talbot et al., 2008] Talbot JA, Sheldrick R, Caswell H, Duncan S. Sexual function in men with epilepsy: how important is testosterone? Neurology 2008; 70: 1346-52.