The relationship between somatosensory amplification, alexithymia, and neuroticism

The relationship between somatosensory amplification, alexithymia, and neuroticism

Journal of Ps3'chomatic Research, Voh 38, No. 6, pp. 515-521, 1994 Copyright ~) 1994 Elsevier Science Ltd Printed in Great Britain. All rights reserve...

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Journal of Ps3'chomatic Research, Voh 38, No. 6, pp. 515-521, 1994 Copyright ~) 1994 Elsevier Science Ltd Printed in Great Britain. All rights reserved 0022 3999/94 $7.00+00

Pergamon 0022-3999(93)E0020-Q

THE RELATIONSHIP BETWEEN AMPLIFICATION, ALEXITHYMIA,

SOMATOSENSORY AND NEUROTICISM

THOMAS N . W~SE*t a n d LEE S. M A N N * t

(Received 27 May 1993; accepted & rev&edform 25 October 1993) Abstract--Both amplification of normal visceral phenomena and the personality trait of alexithymia are factors in the process of somatization, whereby somatic symptoms become metaphors for emotional distress. The relationship between these two variables was investigated in 101 psychiatric out-patients. Each subject was administered the Somatosensory Amplification Scale (SSA); the Toronto Alexithymia Scale (TAS); the NEO-FFI, which measures five personality factors; and the health locus of control (HLC). In addition, anxiety and depression were quantitatively measured. SSA and TAS significantly correlated only in the female subjects. A regression model found neuroticism to contribute the most variance in predicting SSA while TAS did not fit into the model. Amplification is a perceptual element in potentiating somatization, whereas alexithymia contributes to the cognitive aspects of the process. The role of neuroticism is discussed as a mediating factor.

Keywords: Alexithymia, Somatosensory amplification, Neuroticism, Somatization, Hypochondriasis, Locus of control.

INTRODUCTION

SOMATIZATION,the process whereby physical complaints become somatic idioms for emotional distress, occurs in a variety of psychiatric disorders [1]. Affective, cognitive, and perceptual factors have been suggested to contribute to somatization [2]. Amplification of somatic phenomena appears to be the central perceptual style of somatization. Another trait that may foster somatization is alexithymia, a personality construct that denotes both the cognitive style of externally oriented, concrete thinking, and the inability to identify and report specific emotional states [3]. The relationship, if any, between somatosensory amplification and alexithymia is not known. This report investigates these traits in a group of psychiatric out-patients. METHODOLOGY The subjects were 101 consecutive psychiatric out-patients referred for evaluation to the senior author (TNW) during a 6 month period from August 1992 through February 1993. All patients received a full psychiatric evaluation by the senior author (TNW) to ascertain the presence of DSM-IIIR Axis I diagnoses [4]. Axis-II diagnoses were not utilized because of the lower reliability of such categorical personality disorders. All somatic complaints were evaluated by a primary care physician prior to psychiatric evaluation. Patients were excluded from the study if cognitively impaired, psychotic or over the age of 75.

*Department of Psychiatry at Fairfax Hospital. tGeorgetown University School of Medicine. Address all correspondence to: Thomas N. Wise, M.D. Fairfax Hospital, 3300 Gallows Road, Falls Church, VA 22046, U.S.A. 515

516

T.N. WISE and L. S. MANN

Somatosensory amplification was measured by a ten-item self-report inventory, the Somatosensory Amplification Scale (SSA), which has been demonstrated to measure in a reliable and valid manner an individual's sensitivity to normal bodily sensations that do not denote serious disease [5]. The scale has been demonstrated to positively correlate with hypochondriacal concerns as well as anxiety and depression. Alexithymia was rated dimensionally using the Toronto Alexithymia Scale (TAS) [6, 7]. The TAS is a twenty-six item self-report inventory demonstrated to have internal consistency, good reliability (c~ = 0.78), as well as construct and criterion validity to measure alexithymic characteristics. The salient features of alexithymia, as measured by the TAS, include a somatic focus, an analytic cognitive style, an inability to fantasize and the inability to identify or report emotional distress. The TAS global score as well as the three factors developed in previous study: (a) inability to identify and report feelings, (b) inability to daydream, and (c) a concrete cognitive style were utilized [8]. Locus of control was measured by the eleven item Health Locus (~f Control Scale (HLC). The HLC measures personal beliefs regarding control of one's health. The reliability coefficient to measure the internal consistency of item content for HLC was 0.55 [9]. This was similar to the HLC coefficients in other studies [10]. Personality was assessed utilizing the NEO Five Factor Inventor)' (NEO-FFI), a sixty-item self-report questionnaire that measures five domains of personality based upon a trait model [I 1]. The five dimensions are neuroticism, extroversion, agreeableness, openness and conscientiousness [12]. Lastly, assessment of patients' dysphoric affective states were measured quantitatively. Depressed and anxious affect were each assessed utilizing a 100 mm visual analogue scale with a greater value indicating a more dysphoric affect. These scales have been demonstrated to provide a valid and reliable assessment of global affect and to correlate significantly with other self-rated psychometric inventories [13- 15].

RESULTS T h e d i a g n o s e s o f the s t u d y s a m p l e w e r e t w e n t y - n i n e p a t i e n t s w i t h m a j o r m o o d disorders; forty-two with adjustment reactions with depressed or anxious mood; f o u r t e e n w i t h a n x i e t y d i s o r d e r s ; six w i t h a l c o h o l a b u s e ; o n e w i t h a n e a t i n g d i s o r d e r and nine with no psychiatric disorder. T a b l e s I, I I A a n d I I B list d e m o g r a p h i c a n d clinical i n f o r m a t i o n p a r t i t i o n e d by g e n d e r . M a l e s w e r e m o r e e d u c a t e d (yr) (t = 3.3, 96 dr, p < 0.01); a n d f e m a l e s s c o r e d h i g h e r o n the S S A (t = 3.4, 99 df, p < 0.001). A n a n a l y s i s o f c o v a r i a n c e , c o n t r o l l i n g for t h e effect o f e d u c a t i o n ( F = 0.17, N S ) , still r e s u l t e d in significant m a i n effects for sex ( F = 9.3, p < 0.01) u p o n the S S A . O u r s u b j e c t s a p p e a r to lie m i d w a y b e t w e e n B a r s k y ' s f o r m a l l y d i a g n o s e d h y p o c h o n driacs a n d his c o n t r o l s [5]. T h e S S A m e a n s in this s t u d y s i g n i f i c a n t l y differ f r o m B a r s k y ' s c o h o r t o f p a t i e n t s in a m e d i c a l o u t p a t i e n t d e p a r t m e n t w h e r e f o r t y - o n e h y p o c h o n d r i a c a l p a t i e n t s h a d significantly e l e v a t e d S S A scores c o m p a r e d to o u r s (t = - 2.4, p < 0.02). But his c o n t r o l g r o u p o f m e d i c a l o u t - p a t i e n t s w h o w e r e n o t

TABLEI.

DEMOGRAPHICCHARACTERISTICS

N

Age (~,SD)

Education (~¢,SD)

Male

53

46 (13)

16 (3)

W: 51 B: 2

Female

48

42 (12)

15 (2)

W: 47 B: 1

Race

Marital status Mar: Sin: Div: Wid: Mar: Sin: Div: Wid:

36 11 5 I 36 9 2 1

Somatosensory amplification, alexithymia, and neuroticism TABLE IIA.

517

SUMMARYPSYCHOMETRICDATA

TAS (X,SD)

Male Female

SSA

HLC

Anxiety

Depression

(.~',SD)

(Tt~,SD)

(.x',SD)

(~-,SD)

Total

Feelings

Daydream

Analytic

23.1 (5.3) 26.9 (5.9)

33,4 (6.2) 34.5 (6.7)

48.2 (33.2) 60.3 (32.7)

39.7 (28.0) 48.2 (30.3)

63.3 (11,2) 67.8 (12.2)

22.4 (6.8) 24.3 (7.6)

10.3 (3.5) 11.6 (3.3)

8.9 (2.5) 9.8 (2.7)

TABLE lIB.

SUMMARYNEO-FFI-PROEILES

Sex

Mean T-scores

SD

Count

Male

Neuroticism Extraversion Openness Agreeableness Conscientiousness

73.5 53.7 63.9 43.9 50.8

29.7 33.5 27.7 32.8 36.4

53 53 53 53 53

Female

Neuroticism Extraversion Openness Agreeableness Conscientiousness

73.6 46.1 63.2 54.9 47.3

26.4 30.5 28.9 32.2 31.6

48 48 48 48 48

TABLE 11I. PARTIALCORRELATIONCOEFFICIENTSCONTROLLINGFOR DEPRESSION SSA Total TAS HLC

r = 0.24* -

HLC

Neuroticism 0.38***

Extroversion 0.40***

Openness Agreeable - 0.40*** - 0.23*

Conscientious - 0.32**

*p < 0.05; **p < 0.01; ***p < 0.001.

h y p o c h o n d r i a c a l were s i g n i f i c a n t l y l o w e r amplifiers t h a n o u r p s y c h i a t r i c c o h o r t (t = 5.8, p < 0.0001). T h e p r e v a l e n c e o f a l e x i t h y m i a in this s t u d y c o h o r t ( 3 0 . 7 % ) was less t h a n a r e c e n t r e p o r t by T a y l o r et al., [16] w h e r e 3 9 . 8 % were f o u n d to score in the a l e x i t h y m i c r a n g e o f the T A S [12]. T h e m a l e subjects in this s t u d y were less a l e x i t h y m i c t h a n T a y l o r ' s s a m p l e (t = - 4.1, p < 0.001) w h e r e a s the female subjects in T a y l o r ' s s t u d y were n o t significantly different f r o m this r e p o r t (t = 0.008, p = 0.983). P a r t i a l c o r r e l a t i o n coefficients c o n t r o l l i n g for d e p r e s s i o n revealed T A S to c o r r e l a t e positively with S S A a n d n e u r o t i c i s m ; a n d n e g a t i v e l y c o r r e l a t e with e x t r o v e r s i o n , o p e n n e s s a n d c o n s c i e n t i o u s n e s s ( T a b l e III). W h e n stratified b y g e n d e r the significa n c e o f the p a r t i a l c o r r e l a t i o n was m a i n t a i n e d o n l y for females (r = 0.37, p < 0.001) w h e r e a s the c o r r e l a t i o n for m a l e s was n o t s i g n i f i c a n t (r = 0.24, p > 0.239).

518

T.N. WISEand L. S. MANN

A stepwise hierarchical multiple regression was performed to predict SSA. The first variable forced to enter the equation was TAS (adjusted R square = 9.3%). The next variable that entered the equation was neuroticism, which accounted for an additional 4.3% of the variance. The final variable that entered was conscientiousness, which explained another 3.6%. This model explained a total of 17.1% of the variance. Extraversion, openness and agreeableness did not enter the equation. Rather than entering gender into the regression equation, we can separate stepwise hierarchical regressions since we demonstrated SSA gender differences. In the male only model TAS was forced to enter first, accounting for an adjusted R square of 1% (F = 1.4, p = 0.23), hence it was not significant. We then altered the model and ran a hierarchical regression and the first variable to enter was neuroticism, accounting for an adjusted R square of 10.4. Conscientiousness explained an additional 7% of the variance, resulting in the model explaining 17.4% of the variance for males only. TAS, extraversion, openness and agreeableness did not enter the equation. A stepwise hierarchical regression was run for the female only group, and TAS was forced to enter first, accounting for an adjusted R square of 13.0. The remaining variables neuroticism, extraversion, openness, agreeableness and conscientiousness did not enter the equation. Models were then developed which categorically designated subjects as alexithymic or nonalexithymic. Using a method proposed by Parker et al. [17] total TAS was dichotomized. All patients with a TAS score less than or equal to 62 were placed in the nonalexithymic group (N = 43); and all patients greater than or equal to a TAS of 74 were denoted as alexithymic ( N - - 27). One-way analysis of variance revealed alexithymic individuals to score significantly higher on the SSA ( F = 11.4, df 68, l, p < 0.01); higher on depression ( F = 5.5, df l, 66, p < 0.05); and less education (F = 7.0, df 1, 66, p < 0.01). Utilizing multivariant analysis, high alexithymic individuals significantly differed on the five dimensions of the N E O - F F I from those not alexithymic. (Hotellings t = 10.6, df 5, p < 0.001). Univariant analysis revealed a higher mean score on the personality dimensions of neuroticism ( F - - 20.7, df 1, 67, p < 0.001) and conscientiousness ( F - - 10.1, df 1, 67, p < 0.01) but lower on extraversion ( F = 10.1, df 1, 67, p < 0.01) and lower on openness ( F = 16.5, df 1, 67, p < 0.001).

DISCUSSION Somatization denotes the process in which individuals complain of physical symptoms assumed to be related to underlying emotional distress [18]. Amplification of somatic symptoms has been suggested to be the essential perceptual process in the phenomenon of somatization [19]. Alexithymia, is a construct that encompasses both cognitive and affective styles and has been suggested to foster somatization. Utilizing the Schalling-Sifneos Personality Scale, which may be a less reliable measure of alexithymia, Shipko found somatizing patients were more commonly alexithymic [20]. Other data suggests that the Toronto Alexithymia Scale significantly correlates with other measures of somatization such as the somatization subscale of the SCL-90 and Pennebaker's Inventory of Limbic Languidness [21].

Somatosensoryamplification,alexithymia,and neuroticism

519

The contribution of alexithymia to predict amplication was only significant in females in the regression models developed. The significant bivariant correlation between somatosensory amplification and alexithymia when controlled for depression, was not maintained when the sample was stratified by sex, as only in women did SSA significantly correlate with TAS. These findings in female subjects support the previous data that women more commonly endorse functional somatic symptoms. In a community-based epidemiologic catchment area study, Escobar et al. [22] reported that somatic complaints were significantly greater in women, especially those with dysthymia and depression. The significant contribution of neuroticism, however, suggests the importance of negative affectivity or trait neuroticism in the process of somatization. A variety of researchers have reported that individuals disposed to anxiety, depression, worry and vulnerability report more somatic complaints. Costa et al. [23], found that neuroticism, was significantly related to increased somatic complaints including chest pain, but was not related to objective pathology such as coronary artery disease. The exact mechanism whereby neuroticism contributes to somatosensory amplification is not known. Pennebaker has implicated the cognitive style of selective search for information that may link amplification with negative affectivity and alexithymia [24]. Alexithymic individuals, unable to accurately report affective distress, externally oriented and limited in introspection may amplify normal somatic sensations and cognitively attribute them with negative implications. The alexithymic group had a markedly lower conscientiousness score which reaffirms previous data that this personality dimension is significantly related to alexithymia. Alexithymic traits may be secondary to depressed mood, but the relationship does not appear to be a function of such dysphoria since the partial correlational coefficients remained significant after covarying for depression and anxiety [25]. This supports Acklin's data that alexithymic subjects were vacillating and ineffective in making decisions [26, 27]. Keltikangas-Jarvinen found that alexithymia was significantly associated with obsessional personality patterns utilizing the Lazare, Klerman and Armour personality inventory [28]. Similar findings were reported by Wise et al. [29] when the face content of the TAS was significantly correlated with the obsessoid style. This association, however, demands further study since Bagby e t al. [7] found no relationship between alexithymia and the NEO-PI domain of conscientiousness. Alexithymic patients were also more introverted which supports previous reports linking alexithymia as a trait to both introversion and depression in that the introvert reports low energy and less proclivity for socialization and is thereby prone to depression [30]. Alexithymic individuals are also reported to be more socially anhedonic [31]. Alexithymia traits were inversely correlated with the openness domain of the five factor model. The openness facet denotes limited daydreaming and thus overlaps with the definition of alexithymia but also may explain why such patients are unable to imagine that somatic complaints are augmented by emotional distress [32]. The lack of contribution from health locus of control reaffirms that alexithymia and this cognitive style do not correlate and are distinct dimensions [33]. In summary, the TAS measures both a cognitive and affective phenomena whereas the SSA focuses upon a perceptual style. The two appear to be interrelated and occur within a broader setting of negative affectivity as measured by neuroticism. Thus amplification, alexithymia, and neuroticism are all interrelated but each variable

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emphasizes a more specific phenomenon. Somatosensory amplification reflects visceral perception; alexithymia, denotes the cognitive inability to accurately report a full range of affects and a tendency to externalize. Finally, neuroticism refers to an increased tendency to experience negative and dysphoric affects. REFERENCES 1. KELLNERR. Somatization, theories and research. J Nerv Ment Dis 1990; 178:150 160. 2. BARSKVA J, GOODSONJD, LANE RS. The amplification of somatic symptoms. Psychosom Med 1988; 50: 510-519. 3. TAYLORGJ, BAGBVRM, PARKERJD. The alexithymia construct. A potential paradigm for psychosomatic medicine. Psychosomatics 1991; 32: 153-164. 4. Diagnostic and Statistical Manual of Mental Disorders. Third Edn revised. Washington: American Psychiatric Association, 1987. 5. BARSKVA J, WVSHAKG, KLERMANGL. The somatosensory amplification scale and its relationship to hypochondriasis. J Psychiat Res 1990; 24:323 334. 6. BAGBVRM, TAYLORG J, PARKERJD. Construct validity of the Toronto Alexithymia Scale. Psychother Psyehosom 1988; 50:29 34. 7. BAGBV RM, TAYLOR G J, RYAN D. Toronto Alexithymia Scale: Relationship with personality and psychopathology measures. Psychother Psychosom 1986; 45: 207-215. 8. MANNLS, WiSETN, ShAY L. Factor analysis of the Toronto Alexithymia Scale. Po'chother P.~'chosom 1992; 58: 40~,5. 9. WALLSONBS, WALLSOY KA, KAPLANGD, MALDESSA. Development and validation of the health locus of control scale. J Consult Clinical Psychol 1976; 44: 58(~ 585. 10. WALLSTONKA, WALLSTONBS. Health locus of control scales. In Research with the Locus of Control Construct, Volume I (Edited by LEFCOE~THM), p. 194. New York: Academic Press, 1981. 11. NEO-PI Manual and NEO-FFI Supplement. Odessa, Florida: Psychological Assessment Resources Inc,, 1991. 12. COSTAPT, McCRAE RR. Personality disorders and the five factor model of personality. J Person Dis 1990; 4" 362-371. 13. LUR~ARE. The validity and reliability of the visual analogue scale mood scale. J Psychiat Res 1973: 12: 51-57. 14. MORRISONDP, PECK DF. Do self-report measures of affect agree? A longitudinal study. Br J Clin Psychol 1990; 29: 395-400. 15. SUTHERLANDH J, LOCKWOODGA, CUNNINGHAMAJ. A simple, rapid method for assessing psychological distress in cancer patients: evidence of validity for linear analogue scales. J Psyehosoc Onco11989; 7: 31~43. 16. TAYLORGJ, PARKERJO, BAGBYRM, ACKL1NMW. Alexithymia and somatic complaints in psychiatric out-patients. J Psychosom Res 1992; 36: 417~24. 17. PARKrRJD, TAYLORGJ, BAGBVRM. The alexithymia construct: relationship with sociodemographic variables and intelligence. Compr Psychiatry 1989; 30" 434~441. 18. L1POWSKIZJ. Somatization: The concept and its clinical application. Am JPsychiatry 1988; 145:1358 1368. 19. BARSK¥AJ, GOODSONJD, LANE RS. The amplification of somatic symptoms. Psychosom Med 1988; 50: 510-519. 20. SmPKO S. Alexithymia and somatization. Psychother Psychosom 1982; 37:193 201. 21. PENNE~AKER JW, WATSON D. The psychology of somatic symptoms. In Current Concepts of Somatization, Research and Clinical Perspectives (Edited by KmMAYERLJ, ROBBI~qSJM), pp. 21-36. Washington: American Psychiatric Press, 1991. 22. ESCOBARJ|, BtJR~AMMA, KARNOM. Somatization in the community. Arch Gen Psychiatry 1987; 44: 713 718. 23. COSTAPT. Influence of the normal personality dimension of neuroticism on chest pain symptoms and coronary artery disease. Am J Cardiol 1987; 60:205 265. 24. PENNEBAKERJW. The Psychology of Physical Symptoms. New York: Springer, 1982. 25. WISE TN, MANN LS, MITCHELL JD, HRYVNIAK M, HILL B. Secondary alexithymia: An empirical validation. Compr Psychiatry 1990; 31: 284~-288. 26. ACKLINMW, ALEXANDERG. Alexithymia and somatization. A Rorschach study of four psychosomatic groups. J Nerv Ment Dis 1988; 176" 343-350. 27. ACKLINMW, BERNATE. Depression, alexithymia, and pain prone disorder: A Rorschach study. J Pers Assess 1987; 51: 462~79.

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