Crichton Royal Hospital, Dumfries, Scotland, UK
Correspondence: Professor R. G. McCreadie, Department of Clinical Research, Crichton Royal Hospital, Dumfries DG1 4TG, UK. Tel: 01387 244000; fax: 01387 257735; e-mail: rgmccreadie_crh{at}compuserve.com
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ABSTRACT |
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Aims To measure rates of sexual dysfunction in people with schizophrenia compared with the general population.
Method Sexual dysfunction was assessed by a self-completed gender-specific questionnaire. Ninety-eight (73%) of 135 persons with schizophrenia and 81 (71%) of 114 persons recruited as controls returned the questionnaire.
Results At least one sexual dysfunction was reported by 82% of men and 96% of women with schizophrenia. Male patients reported less desire for sex, were less likely to achieve and maintain an erection, were more likely to ejaculate more quickly and were less satisfied with the intensity of their orgasms. Female patients reported less enjoyment than the control group. Sexual dysfunction in female patients was associated with negative schizophrenic symptoms and general psychopathology. There was no association between sexual dysfunction and type of antipsychotic medication.
Conclusions People with schizophrenia report much higher rates of sexual dysfunction than do the general population. Men and women with schizophrenia have a different pattern of sexual dysfunction.
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INTRODUCTION |
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METHOD |
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Participants
Patients
The patients were recruited as part of a larger lifestyle survey
(McCreadie on behalf of Scottish
Comorbidity Study Group, 2002). The key informant
method was used to find cases (McCreadie,
1982). Patients living in Nithsdale with a clinical ICD10
diagnosis of schizophrenia (World Health
Organization, 1992) were identified in April 1999. These included
all current in-patients, day patients and out-patients at Crichton Royal
Hospital, Dumfries, and patients supported by community psychiatric nurses. In
addition, all general practitioners in Nithsdale were asked to notify us of
any other patients with schizophrenia known to them. Finally, mental health
officers (social workers) and voluntary agencies were asked to identify any
others.
General population control group
Through the use of the Community Health Index (a national database that
holds details for all patients registered with a Scottish general
practitioner), a control group was identified. For each patient interviewed
(excluding long-stay in-patients) a person of the same gender, age (within 1
year) and postcode area of residence (matched to five characters) was
recruited as a control.
Assessments
A self-completed gender-specific questionnaire was devised for the study
(by S.M.). Initial versions were piloted. The final version contains 11
questions for men and 10 for women (see Appendix). The questions cover four
areas of sexual functioning: desire, arousal, performance and satisfaction.
The participants were given the questionnaire by one of the researchers, and
asked to complete it in the privacy of their home. The questionnaire used
colloquial language for erection, ejaculation and
orgasm to make questions more understandable.
Patients' mental state was rated by one of four psychiatrists (S.M., J.H., T.M., R.G.M.) using the Positive and Negative Syndrome Scale (PANSS) for schizophrenia (Kay et al, 1987). This scale gives a total score and scores on positive symptom, negative symptom and general psychopathology sub-scales. Current medication was recorded. As part of the larger study, both patients and controls completed a smoking questionnaire recently used in a health and lifestyle survey of the general population in south-west Scotland (Waldron et al, 1995).
Statistical analysis
Data were analysed as a casecontrol study. For comparisons between
groups, chisquared tests, Fisher's exact tests and unpaired t-tests
were used. The casecontrol comparison was unmatched for the following
reasons. The answers to questions 2 and 3 (see Appendix) determined whether
the participant had any sexual activity, either intercourse or masturbation.
If the participant did not, then the response to subsequent questions (4-11
for men, 4-9 for women), namely e (no sexual activity or
masturbation), was ignored. The remaining number of people in each group who
circled a or b in response to these questions was
compared with the number circling c or d.
Two-sided significance tests were used, and as there were many comparisons only differences at least at the 1% level are reported.
Ethical approval
The Dumfries and Galloway Research Ethics Committee approved the study. All
patients gave written informed consent.
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RESULTS |
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Patients and controls
We report the results in cases where both the patient and the recruited
control returned the questionnaire. There were 60 such patients and controls;
34 male and 26 female. More patients than control participants were single and
were living alone (Table
1).
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Men
The following statistically significant differences were found between male
patients and their controls (Table
2). More patients than controls did not have sexual intercourse
and did not masturbate: 9 (27%) v. 0 (0%); 2=8.2,
d.f.=1, P<0.002. More had at least one sexual dysfunction
(answered a or b to questions 1, 4-11 for men;
questions 1, 4-9 for women): 28 (82%) v. 13 (38%);
2=12.04, d.f.=1, P=0.0005.
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Male patients had less desire for sexual intercourse: 17 (52%) v.
4 (12%); 2=12.30, d.f.=1, P=0.001; were less likely
to achieve an erection: 12 (52%) v. 3 (9%);
2=11.58,
d.f.=1, P=0.0007; were less likely to maintain an erection: 8 (36%)
v. 2 (6%);
2=6.51, d.f.=1, P=0.009; were
more likely to ejaculate too quickly: 8 (35%) v. 1 (3%);
2=8.20, d.f.=1, P=0.002; and were less satisfied with
the intensity of their orgasms: 8 (33%) v. 1 (3%);
2=7.73, d.f.=1, P=0.002.
Women
More female patients than controls had at least one sexual dysfunction: 23
(96%) v. 14 (58%); 2=7.55, d.f.=1, P=0.006;
and patients were less likely to enjoy sex: 6 (46%) v. 1 (5%);
2=6.07, d.f.=1, P=0.007. Although 13 (50%) female
patients did not have sexual intercourse and did not masturbate and 19 (73%)
had little or no desire for sex, these numbers were not significantly higher,
statistically speaking, than in the control group (n=5, 19% for
sexual intercourse and masturbation; n=11, 46% for sexual
desire).
Factors associated with sexual dysfunction
Within the group of patients (n=98) we examined associations
between sexual dysfunction and having or not having a partner, mental state,
types of antipsychotic medication and smoking. The areas of sexual dysfunction
examined were those in which we had found differences between patients and
controls.
Partners
There was no difference in any area of sexual dysfunction between those who
did and did not have a partner.
Mental state
There was no difference between men and women patients in mean total and
sub-scale PANSS scores. In male patients there was no statistically
significant association between any area of sexual dysfunction and PANSS total
and sub-scale scores. In female patients, those reporting problems with
enjoyment during sex had higher negative symptom scores (mean 16.2, s.d. 7.8
v. mean 10.6, s.d. 4.5; t=0.4, d.f.=22, P=0.01);
general psychopathology scores (mean 31.3, s.d. 4.5 v. mean 23.6,
s.d. 6.4; t=3.2, d.f.=22, P=0.001); and total scores (mean
62.0, s.d. 12.6 v. mean 47.4, s.d. 14.9; t=2.5, d.f.=22,
P=0.01).
Medication
As only eight patients were not taking antipsychotic medication, numbers
were too small to compare those taking and not taking such drugs. There was no
statistically significant difference between men and women in the proportion
of those taking typical and atypical antipsychotic drugs
(Table 3). In both men and
women patients there was no association between type of antipsychotic
medication and sexual dysfunction, or between taking or not taking
antidepressant medication and sexual dysfunction.
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Smoking
Sixty-five (66%) patients were current smokers. There was no statistically
significant difference in the number of men (41, 77%) and women (24, 55%) who
smoked, nor in the mean number of cigarettes smoked per day (men 30, s.d. 10;
women 22, s.d. 11). Among male patients, those who did not smoke had less
desire for sexual intercourse: 10 (83%) v. 14 (36%);
2=6.90, d.f.=1, P=0.01. In female patients there was
no association between smoking and any area of sexual dysfunction.
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DISCUSSION |
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In our study, which had a response rate of 72%, we used a self-completed, gender-specific questionnaire. People were given the opportunity to complete it in privacy and in their own time. The advantages of a self-completed questionnaire include less embarrassment, which might encourage people to be more honest in their answers, and the absence of interviewer bias. A disadvantage of this method is that responders are not able to address any points they do not understand within the questionnaire. To overcome this problem we used colloquial explanations for such words as erection and orgasm and used the same question type throughout. Only 9% of the questionnaires were incomplete, which suggests that most people had understood the questions being asked.
We devised our own self-rating questionnaire because at the time we could find none that could be completed by both men and women, by those with and without a partner, and that covered the main areas of sexual functioning: namely, desire, arousal, performance and satisfaction. A recent paper (Smith et al, 2002) used a questionnaire somewhat similar to ours.
Reliability and validity
When this paper was first submitted for publication an assessor sought
information about the reliability and validity of the scale. In only one scale
used in the studies quoted in the first paragraph of this discussion was
reliability assessed (Smith et
al, 2002).
Although they cannot be measured, we believe that our scale has both content validity (the scale contains the number and content of questions appropriate to the attribute to be measured) and face validity (the scale appears to measure what it is supposed to measure). Interrater reliability is not relevant as it is only applicable to observer-rated scales. The scale does not lend itself to assessment of split-half reliability. However, we have some additional evidence that the scale, or at least part of it, may be both reliable and valid. As a result of this survey, carried out in 1999, we realised that erectile dysfunction was a major problem for men with schizophrenia. In 2002 we embarked on a randomised, placebo-controlled study of sildenafil in erectile dysfunction in men with schizophrenia. To enter the study, patients fulfilled the following criterion: the patient for 6 months or longer has been unable to achieve or maintain an erection, sufficient for satisfactory sexual performance either with a partner or through masturbation. Seven men who volunteered for the sildenafil study and fulfilled the entry criterion had been reviewed in 1999, and their psychotropic medication had remained unchanged over the subsequent 3 years. Of the seven, six (86%) in the 1999 survey had reported either never or only occasionally getting an erection. Therefore the patients' assessments of themselves had not changed over 3 years, a measure of testretest reliability. Also, if patients did not have erectile dysfunction, it is unlikely that they would volunteer for such a study a measure of predictive validity.
Patients and controls
The principal difference between the patient and control groups was that
the majority of the people in the latter had partners. However, in our
questionnaire responders were asked to answer each question with reference to
either sexual intercourse or masturbation. A previous study
(Aizenberg et al,
1995), which considered only those with a partner, found higher
rates of sexual dysfunction in people with schizophrenia. One study found that
having a partner was protective against sexual dysfunction
(Raboch, 1984); another did
not (Kockott & Pfeiffer,
1996). In our study the level of sexual dysfunction was the same
in patients with and without partners.
Sexual dysfunction
Sexual dysfunction was common in patients, with 82% of men and 96% of women
reporting at least one sexual dysfunction. Fewer male patients than controls
reported any sexual activity, whether sexual intercourse or masturbation.
Where sexual activity was reported, male patients reported a broader range of
sexual dysfunction than controls, with desire, performance and satisfaction
all affected. The most prominent problem was difficulty achieving an erection
(52%). This percentage is a little higher than in previous studies, in which
the percentages were 38% (Ghadirian et
al, 1982) and 47% (Teusch
et al, 1995).
There were fewer differences between female patients and controls, largely because sexual dysfunction was also wide-spread in the control group. Differences were in enjoyment of sex, a finding reported in a previous study (Miller & Finnerty, 1996). In another study (Teusch et al, 1995) 60% of women lacked interest in sex and 92% had at least one sexual dysfunction. Ghadirian et al (1982) reported that 30% had current difficulty in sexual functioning. Finally, Friedman & Harrison (1984) found that 60% of female patients had never had an orgasm, compared with 13% of controls.
Mental state
A previous study (Kockott &
Pfeiffer, 1996) found an association in both male and female
patients between being less well mentally and having sexual dysfunction. A
study of long-stay patients found that the severely ill patients had less
interest in sex (Lyketsos et al,
1983). A study of patients receiving conventional antipsychotic
medication found an association between depression and sexual dysfunction
(Smith et al, 2002).
In our study, there was an association in female but not in male patients
between a poorer mental state and sexual dysfunction. Scores were higher in
both the negative symptoms and general psychopathology sub-scales; perhaps
symptoms of withdrawal, anxiety and depression contribute to sexual
dysfunction in women patients.
Medication
Most classes of antipsychotic drugs are implicated in sexual dysfunction
(Sadock, 1989). However,
evaluating their effect on sexual dysfunction is complicated by the illness
itself, compliance with treatment, and an incomplete understanding of all the
variables involved in human sexual functioning.
In our study there were too few patients not receiving antipsychotic medication to compare those taking and not taking such drugs. One previous study (Kockott & Pfeiffer, 1996) found a trend only between receiving antipsychotic medication and sexual dysfunction. Another study (Aizenberg et al, 1995) found that the quality of coital erections was significantly more reduced in men with schizophrenia treated with antipsychotic medication than in a similar untreated group.
The newer atypical antipsychotic drugs have a greater affinity for serotonin (5-hydroxytryptamine) 5-HT2 receptors than for dopamine D2 receptors. This is believed to account for the reduced incidence of hyperprolactinaemia in patients receiving this class of antipsychotic. Studies suggest that these drugs may cause fewer sexual side-effects (Meltzer et al, 1979; Aizenberg et al, 2001). However, in our study we found no difference in the reporting of sexual dysfunction between those taking typical and atypical antipsychotic drugs, as did a previous study (Hummer et al, 1999). This may reflect the impact that the schizophrenic illness itself has on sexual functioning. It may also be that dopamine receptor blockade and hyperprolactinaemia are only a small part of the complex relationship between illness, treatment and sexual functioning.
Smoking
In our study 67% of patients were current smokers. Non-smoking male
patients had less desire for sex than did those who smoked. Lower blood levels
of antipsychotic drugs in men who smoke may be one possible explanation of
this finding; smoking increases the metabolism of antipsychotic drugs by
inducing hepatic microsomal enzymes
(Salokangas et al,
1997).
Treatment of sexual dysfunction
We conclude that sexual dysfunction is very common indeed in patients with
schizophrenia. This is yet another aspect of the poor quality of life led by
many people with schizophrenia that should be addressed. To this end, we have
now embarked on the first double-blind, placebo-controlled, randomised trial
of sildenafil in male patients with schizophrenia and erectile
dysfunction.
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Clinical Implications and Limitations |
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LIMITATIONS
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APPENDIX |
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For men:
For women:
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ACKNOWLEDGMENTS |
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REFERENCES |
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Aizenberg, D., Modai, I., Landa, A., et al (2001) Comparison of sexual dysfunction in male schizophrenic patients maintained on treatment with classical antipsychotics versus clozapine. Journal of Clinical Psychiatry, 62, 541-544.[Medline]
Friedman, S. & Harrison, G. (1984) Sexual histories, attitudes and behaviour of schizophrenic and normal women. Archives of Sexual Behaviour, 13, 555-567.
Ghadirian, A. M., Chouinard, G. & Annable, L. (1982) Sexual dysfunction and plasma prolactin levels in neuroleptic treated schizophrenic outpatients. Journal of Nervous and Mental Disease, 170, 463-467.[Medline]
Hummer, M., Kemmler, G., Kurz, M., et al
(1999) Sexual disturbances during clozapine and haloperidol
treatment for schizophrenia. American Journal of
Psychiatry, 156,
631-633.
Kay, S., Fishbein, A. & Opler, L. A. (1987) The positive and negative symptom scale (PANSS) for schizophrenia. Schizophrenia Bulletin, 13, 261-275.[Medline]
Kockott, G. & Pfeiffer, W. (1996) Sexual disorders in nonacute psychiatric outpatients. Comprehensive Psychiatry, 37, 56-61.[Medline]
Kotin, J., Wilbert, D. E., Verburg, D. et al (1976) Thioridazine and sexual dysfunction. American Journal of Psychiatry, 133, 82-85.[Abstract]
Lyketsos, G. C., Sakka, P. & Mailis, A. (1983) The sexual adjustment of chronic schizophrenics: a preliminary study. British Journal of Psychiatry, 143, 376-382.[Abstract]
McCreadie, R. G. (1982) The Nithsdale schizophrenia survey I. Psychiatric and social handicaps. British Journal of Psychiatry, 140, 582-586.[Abstract]
McCreadie, R. G. on behalf of the Scottish Comorbidity Study
Group (2002) Use of drugs, alcohol and tobacco by people with
schizophrenia: case-control study. British Journal of
Psychiatry, 181,
321-325.
Meltzer, H. Y., Goode, D. J., Schyve, P. M., et al (1979) Effects of clozapine on human serum prolactin levels. American Journal of Psychiatry, 135, 1550-1555.
Miller, L. J. & Finnerty, M. (1996) Sexuality, pregnancy and childrearing among women with schizophrenia-spectrum disorders. Psychiatric Services, 47, 502-506.[Abstract]
Mullen, B., Brar, J. S., Vagnucci, A. H., et al (2001) Frequency of sexual dysfunction in patients with schizophrenia on haloperidol, clozapine or risperidone. Schizophrenia Research, 48, 155-156.[CrossRef]
Raboch, J. (1984) The sexual development and life of female schizophrenic patients. Archives of Sexual Behaviour, 13, 341-349.
Sadock, V. A. (1989) Normal human sexuality and sexual dysfunctions. In Comprehensive Textbook of Psychiatry (5th edn) (eds H. I. Kaplan & B. J. Sadock), pp. 1045-1061. Baltimore, MD: Williams & Wilkins.
Salokangas, R. K. R., Saarijarvi, S., Taiminem, T., et al (1997) Effect of smoking on neuroleptics in schizophrenia. Schizophrenia Research, 23, 55-60.[CrossRef][Medline]
Smith, S., O'Keane, V. & Murray, R. (2002)
Sexual dysfunction in patients taking conventional antipsychotic medication.
British Journal of Psychiatry,
181, 49-55.
Teusch, N., Scherbaum, N., Böhme, H., et al (1995) Different patterns of sexual dysfunctions associated with psychiatric disorders and psychopharmacological treatment. Pharmacopsychiatrica, 28, 84-92.[Medline]
Waldron, G., Chalmers, J., Bone, A., et al (1995) Health and Lifestyles in Dumfries and Galloway in 1995. Dumfries: Dumfries and Galloway Health Board.
World Health Organization (1992) The ICD-10 Classification of Mental and Behavioural Disorders. Geneva: WHO.
Received for publication February 4, 2002. Revision received July 29, 2002. Accepted for publication September 4, 2002.
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