- Email: [email protected]
Personality change following head injury: Assessment with the neo five-factor inventory
Journal o# Psychosomatic Research, Vol. 43. No. 5, pp. 505-511, 1997 Copyright © 1997 Elsevier Science Inc. All rights reserved. 0022-3999/97 $I7.~) + .00
ELSEVIER
S0022-3999(97)00152-9
PERSONALITY CHANGE FOLLOWING HEAD INJURY: A S S E S S M E N T WITH THE N E O FIVE-FACTOR INVENTORY ENGELIEN
LANNOO,* CATHY DE DEYNE,t FRANCIS COLARDYN,t G E E R T D E S O E T E $ and C O N S T A N T I N J A N N E S §
(Received 5 March 1997; accepted 13 May 1997) Abstract--We evaluated personality change following head injury in 68 patients at 6 months postinjury using the NEO Five-Factor Inventory to assess the five personality dimensions of the Five-Factor Model of Personality. All items had to be rated twice, once for the preinjury and once for the current status. Twenty-eight trauma patients with injuries to other parts of the body than the head were used as controis. For the head-injured group, 63 relatives also completed the questionnaire. The results showed no differences between the ratings of head-injured patients and the ratings of trauma control patients. Both groups showed significant change in the personality dimensions Neuroticism, Extraversion, and Conscientiousness. Compared to their relatives, head-injured patients report a smaller change in Extraversion and Conscientiousness. Changes were not reported on the Openness and Agreeableness scales, by neither the head-injured or their relatives, nor by the trauma controls. © 1997 Elsevier Science Inc.
Keywords: Trauma.
Five-Factor Model; Head injury; NEO Five-Factor Inventory; Personality change;
INTRODUCTION T h e p r o b l e m of personality change has been frequently r e p o r t e d as one of the most persistent p r o b l e m s after h e a d injury, and is often cited as an i m p o r t a n t obstacle to social reintegration later postinjury [1-4]. A t one extreme, there m a y be a subtle awareness on the part of the patient and his close relatives of a m i n o r change in personality. A t the o t h e r extreme, there m a y be a dramatic personality disorder resulting in socially unacceptable b e h a v i o r [3]. T h e question can be raised w h e t h e r the r e p o r t e d personality changes following h e a d injury are universal or only present and striking in a limited n u m b e r of cases. It is also not clear as to w h e t h e r r e p o r t e d personality changes result f r o m structural brain damage, or are m o r e psychologically induced and reflect the attempts of the patient to cope with his disabilities. P r i g a t a n o [4, 5] classified personality disorders after h e a d injury along three b r o a d categories. A first g r o u p of disturbances is considered to be reactionary in nature. E x a m p l e s are anxiety, depression, and irritability. T h e y reflect the struggle of the
Departments of *Neuropsychology, tIntensive Care, SData Analysis, and §Psychiatry, University Gent, Gent, Belgium. Address correspondence to: Engelien Lannoo, Department of Neuropsychology 4K3, University Hospital, De Pintelaan 185, 9000 Gent, Belgium. Tel: +32/9/240.45.88; Fax: +32/9/240.45.55: E-mail: [email protected] 505
506
E. LANNOO et al.
damaged organism to adapt to an environment that no longer takes into consideration limited cognitive skills and physical disabilities. A second set of personality changes are neuropsychologically mediated and flow directly from the neuropathological lesions. Examples are impulsiveness, socially inappropriate behavior, unawareness of deficit, and apparent lack of motivation. A final group of personality disorders existed prior to the onset of the brain injury and are considered to be characterological or premorbid in nature. Examples are obsessive or superorderly behavior, a hard-working attitude, and enjoyment of a dependent role. These variable patterns of personality disturbances following head injury create substantial problems in quantifying and measuring them objectively. Postinjury personality disorders have been assessed in many ways, but little effort has been made to relate this assessment to a conceptual model of personality and personality disorders in general. Some researchers [1, 6, 7] applied the Minnesota Multiphasic Personality Inventory (MMPI). From the MMPI, personality disorder scales were derived [8] to yield a self-report measure of the 11 personality disorders described in the Diagnostic and Statistical Manual of Mental Disorders (DSM-III). However, considerable content biases are found to be inherent in the application of the MMPI in cases of neurologic dysfunction because a number of MMPI items tap areas of dysfunction consistent with the sequelae of neurologic damage [9-11]. Moreover, there are theoretical and methodological problems with the application of the DSM-III in the diagnosis of personality disorders [12-14]. Many of these problems might be resolved by using continuous dimensions instead of discrete categories [15]. Such a dimensional alternative could be provided by the Five-Factor Model of personality (FFM) [16, 17], which is a taxonomy of personality traits in terms of five broad dimensions: Neuroticism, Extraversion, Openness to experience, Agreeableness, and Conscientiousness. There is an emergent and growing consensus suggesting that the FFM is a comprehensive classification of personality dimensions that may be an alternative, conceptually useful framework for understanding personality disorders [18]. No previous research reports have been found on the application of the FFM in the investigation of personality changes following head injury. The present study attempts to examine personality change in patients with moderate to severe head injury by the administration of the Neuroticism-Extraversion-Openness Five-Factor Inventory (NEO-FFI) at 6 months postinjury. The N E O - F F I is a questionnaire designed to operationalize the FFM. To separate head injury-related effects from effects due to the sustaining of a traumatic injury, patients with traumatic injuries to parts of the body other than the head were used as controls.
METHOD Subjects Head injured group. This group consisted of 68 head-injured patients admitted to the intensive care
unit at the University Hospital of Gent during a 30-month period (September 1993 to February 1996). Selection criteria included an admission Glasgow Coma Scale score between 9 and 12 for moderate, and of 8 or less for severe head injury, age between 15 and 65 years, no medical history of central nervous system disease or mental retardation, survival for at least 6 months, and willingness to participate in the study. Of these patients, 63 relatives also completed the NEO-FFI. Trauma control group. This group consisted of 28 patients with injuries to other parts of the body than the head, who were admitted to the intensive care unit during the same study period. Other inclusion
507
Personality change following head injury Table I.--Demographic and medical characteristics
Male/female Age Education (years) GCS TFC (days) PTA (days)
Head-injured
Controls
54/13 35 11 7 15 38
20/8 37 12 15 0 0
GCS: Glasgow Coma Scale; TFC: time to follow commands (coma length); PTA: posttraumatic amnesia.
criteria were age between 15 and 65 years, survival for at least 6 months, and willingness to participate in the study. Patients with evidence of minor head injury (loss of consciousness, amnesia, or facial injuries), and patients with a medical history of central nervous system disease or mental retardation, were excluded. This sample matched the head-injured on gender, age, and education (Table I).
Procedure At 6 months postinjury, patients were administered the Dutch version of the NEO Five-Factor Inventory (NEO-FF1) [19]. This questionnaire measures the five personality dimensions of the FFM: Neuroticism (chronic level of emotional adjustment and instability); Extraversion (quantity and intensity of preferred interpersonal interactions); Openness (active seeking and appreciation of experience); Agreeableness (kinds of interactions a person prefers); and Conscientiousness (degree of organization and control in goal-directed behavior) [18]. It consists of 60 items rated on a five point scale. To assess change since the injury, patients were asked to rate the items twice, once (retrospectively) for their preinjury status, and once for their current postinjury status. Because it is generally assumed that head-injured patients cannot reliably report their own behavioral status due to limited self-awareness and anosognosia [20], a close relative of each head-injured patient was also asked to complete the questionnaire. Comparison of the patient's versus relative's report can provide information on how realistic head-injured patients can evaluate their own behavioral strengths and limitations [21].
Data analysis MANOVA procedures for repeated measures were conducted to examine the differences between the preinjury and current ratings of head-injured patients and their relatives on the five NEO-FFI scales, and to examine the differences between preinjury and current ratings of the head-injured compared to the trauma control group. For both analyses, the raw scale scores were used. Analyses were carried out using SPSS.
Table II.--Means and standard deviations of the ratings of head-injured patients and their relatives on the NEO-FFI Head-Injured Preinjury Neuroticism Extraversion Openness Agreeableness Conscientiousness
17 30 22 32 34
(8) (6) (6) (7) (7)
Relatives
Current 20 29 22 31 32
(9) (6) (6) (7) (8)
Preinjury 16 31 20 32 35
(8) (7) (6) (8) (8)
Current 20 27 20 31 31
(6) (7) (5) (8) (9)
pa
pb
pC
0.000 0.000 0.947 0.091 0.000
NS NS (0.003) J NS NS
0.320 0.007 0.341 0.977 0.003
a Main effect of preinjury vs. current ratings. u Main effect of patients' vs. relatives' ratings. c Interaction effect. a p Value in parentheses because the M A N O V A showed a trend toward significance (p < 0.10).
508
E. LANNOO et al. RESULTS
Table II shows the mean values and standard deviations of the ratings of headinjured patients and their relatives on the NEO-FFI. M A N O V A for repeated measures revealed significant differences between preinjury and current ratings of patients and relatives on the NEO-FFI (Hotelling's statistic=0.618, p<0.001). Subsequent univariate tests yielded significant changes on the scales of Neuroticism, Extraversion, and Conscientiousness, and a trend toward a change on the scale of Agreeableness. Analysis of the raw scale scores showed higher ratings on Neuroticism, and lower ratings on Extraversion, Agreeableness, and Conscientiousness (Fig. 1). There was a trend toward a difference between the ratings of patients and relatives (Hotelling=0.175, p =0.088). Subsequent univariate tests showed a significant difference on the Openness scale, with patients rating themselves higher than their relatives (Fig. 1). There was also a significant interaction effect (Hotelling=0.211, p =0.045). Subsequent univariate tests were significant for Extraversion and Conscientiousness, with patients reporting a smaller change than relatives (Fig. 1). Table III contains the mean values and standard deviations of the ratings of the headinjured and trauma control patients on the NEO-FFI. A MANOVA for repeated measures showed no significant differences between patients and controls on the NEO-FFI (Hotelling=0.059, p=0.383). Both groups report significant differences between preinjury and current status (Hotelling=0.398, p<0.001). Subsequent univariate tests revealed significant differences on Neuroticism, Extraversion, and Conscientiousness. Analyses of the raw scale scores demonstrate higher ratings on Neuroticism, and lower ratings on Extraversion and Conscientiousness (Fig. 2). No interaction effect was found (Hotelling=0.092, p =0.152).
40 30352520 "..... "~j •.....
.'.
[ ] Head Injured Preinjury OHead Injured Current [ ] Relative Preinjury [ ] Relative Current
lO N
E
0
A
C
Fig. 1. Ratings of head-injured subjects and their relatives on the NEO-FFI.
Personality change following head injury
509
Table IlL--Means and standard deviations of the ratings of head-injured patients and trauma controls on the NEO-FFI Head-Injured Current
Preinjury
Neuroticism Extraversion Openness Agreeableness Conscientiousness
17 30 22 31 34
Trauma controls
(8) (7) (6) (7) (7)
20 28 22 31 32
Preinjury
(9) (6) (6) (7) (8)
17 31 24 32 36
(8) (4) (6) (4) (5)
Current 21 28 24 31 35
(10) (5) (6) (5) (6)
p~
pb
pc
0.000 0.000 0.782 0.396 0.009
Ns NS NS us US
NS NS NS NS NS
a Main effect of preinjury vs. current ratings. b Main effect of head-injured vs. trauma control ratings. c Interaction effect.
DISCUSSION
The results indicate that head-injured patients report a significant change in personality at 6 months postinjury, but fail to demonstrate any difference between head-injured patients and patients with traumatic injuries to other parts of the body than the head. Compared to preinjury ratings, both groups reported higher ratings on the Neuroticism scale, and lower ratings on the Extraversion and Conscientiousness scales of the NEOFFI. The lack of difference between both groups suggests that the reported personality change might be reactionary in nature, reflecting the attempts of the patients to cope with their disabilities, whether these are related to structural brain damage or to other system injuries. However, it remains possible that head-injury-related personality
ii 30 [ ] Head Injured Preiniury [ ] H e a d Injured Current 25
E~ Controls Preinjury I~! Controls Current
20
15
10 N
E
0
A
c
Fig 2. Ratings of head-injuredsubjects and trauma controls on the NEO-FFI.
510
E. LANNOO et al.
changes present in head-injured patients and not in control patients might not have been measured by the NEO-FFI. When the preinjury and current ratings of head-injured patients and their close relatives on the NEO-FFI were compared, we found an interaction effect. Relatives report a greater change on the Extraversion and Conscientiousness scales than the patients. This suggests that patients tend to underestimate the degree of personality change. However, patients do not seem to be totally unaware of these changes, nor do they deny them, because they also report a change on these scales, but to a lesser degree than do their relatives. However, the control group did not have relatives who were assessed, and it may be that the observed differences between head-injured patients and their relatives also occur in trauma control patients and are in fact unrelated to the head injury. Changes are not reported on the Openness and Agreeableness scales of the NEOFFI, neither by the head-injured patients and their relatives nor by the trauma control patients with other system injuries. On the Openness scale, however, headinjured patients tended to rate themselves higher than do their relatives, both for their preinjury and postinjury status. Whether this trend toward a difference on this scale is typical for head-injured patients, or more universal in the sense that self-reports on this scale always tend to be higher than the ratings of significant others, warrants further investigation. Little information is available on the stability of the personality dimensions of the FFM over time. It can be hypothesized that some of the personality dimensions are prone to change, especially in case of a traumatic life event, whereas others tend to be more stable over time. Our findings are indicative of changeability on the Neuroticism, Extraversion, and Conscientiousness scales, and a stability on the Openness and Agreeableness scales of the NEO-FFI. However, because the reports of the preinjury status were retrospective, and because of the limited time interval between preinjury and current status, these results should be viewed as hypothesis generating and in need of future corroboration, not only in head-injured patients, but also in normal populations and after other significant life events. In conclusion, our findings indicate that traumatic injuries are followed by a change in personality that is probably reactionary in nature. These changes occur in the domains of Neuroticism, Extraversion, and Conscientiousness of the FFM. However, compared to their relatives, head-injured patients tend to underestimate the degree of change.
REFERENCES 1. Kreutzer JS, Marwitz JH, Seel R, Serio CD. Validation of a neurobehavioral functioning inventory for adults with traumatic brain injury. Arch Phys Med Rehabil 1996;77:116-124. 2. Livingston M, Brooks N, Bond M. Patient outcome in the year following severe head injury and relatives' psychiatric and social functioning. J Neurol Neurosurg Psychiatry 1985;48:876-881. 3. O'Shanick G, O'Shanick AM. Personality and intellectual changes. In: Silver JM, Yudofsky SC, Hales RE, eds. Neuropsychiatry of traumatic brain injury. Washington, DC: American Psychiatric Press 1994:163-188. 4. Prigatano GP. Personality and psychosocial consequences of brain injury. In: Prigatano GP, ed. Neuropsychological rehabilitation after brain injury. Baltimore, Maryland: Johns Hopkins University Press 1986:29-49.
Personality change following head injury
51 1
5. Prigatano GP. Neuropsychological deficits, personality variables, and outcome. In: Ylvisaker M, Gobble EM, eds. Community re-entry for head injured adults. Boston: College-HiU Press 1987:1-23. 6. Leininger B, Kreutzer J, Hill M. Comparison of minor and severe head injury emotional sequelae using the MMPI. Brain Inj 1991;5:199-205. 7. Miller HB, Paniak CE. MMPI and MMPI-2 profile and code type congruence in a brain-injured sample. J Clin Exp Neuropsychol 1995;17:58-64. 8. Morey LC, Waugh MH, Blashfield RK. MMPI scales for DSM-III personality disorders: their derivation and correlates. J Pets Assess 1985;49:245-251. 9. Alfano DP, Paniak CE, Finlayson MA. The MMPI and closed head injury. A neurocorrective approach. Neuropsychiatry Neuropsychol Behav Neurol 1993;6:111-116. 10. Bornstein RA, Kozora E. Content bias of the MMPI Sc Scale in neurologic patients. Neuropsychiatry Neuropsychol Behav Neurol 1990;3:200-205. 11. Hamilton JM, Finlayson MA, Alfonso DP. Dimensions of neurobehavioural dysfunction: cross-validation using a head-injured sample. Brain Inj 1995;9:479-485. 12. Nurnberg HG, Raskin M, Levine PE, Pollack S, Siegel O, Prince R. The comorbidity of borderline personality disorder and other DSM-III-R Axis II personality disorders. Am J Psychiatry 1991 ;148:137 1-1377. 13. Skodol AE, Rosnick L, Kellman HD, Oldham J, Hyler SE. Validating structured DSM-III-R personality disorder assessments with longitudinal data. Am J Psychiatry 1988;145:1297-1299. 14. Widiger TA. The DSM-III-R categorical personality disorder diagnoses: a critique and an alternative. Psychol Inquiry 1993;4:75-90. 15. Widiger TA, Frances AJ. Toward a dimensional model for the personality disorders. In: Costa PT, Widiger TA, eds. Personality disorders and the five-factor model of personality. Washington, DC: American Psychological Association 1994:19-39. 16. Digman JM. Personality structure: emergence of the five-factor model. Ann Rev Psychol 1990;50:116-123. 17. McCrae RR. The five-factor model. Issues and applications ]special issue]. J Pers 1992;60. 18. Costa PT, Widiger TA. Introduction: Personality disorders and the five-factor model of personality. In: Costa PT, Widiger TA, eds. Personality disorders and the five-factor model of personality. Washington, DC: American Psychological Association 1993:1-10. 19. Hoekstra HA, Ormel J, De Fruyt F. NEO PI-R. NEO FF-I. Big five Persoonlijkheidsvragenlijsten. Handleiding [NEO PI-R. NEO FF-I. Big Five. Personality questionnaires. Manual]. Lisse: Swets & Zeitlinger 1996. 20. Prigatano GP. Disturbances of self-awareness of deficit after traumatic brain injury. In: Prigatano GP, Schacter DL, eds. Awareness of deficit after brain injury. Clinical and theoretical issues. New York: Oxford University Press 1991:111-126. 21. Prigatano GP, Altman IM, O'Brien KP. Behavioral limitations that traumatic-brain-injured patients tend to underestimate. Clin Neuropsychol 1990:4:163-176.
ELSEVIER
S0022-3999(97)00152-9
PERSONALITY CHANGE FOLLOWING HEAD INJURY: A S S E S S M E N T WITH THE N E O FIVE-FACTOR INVENTORY ENGELIEN
LANNOO,* CATHY DE DEYNE,t FRANCIS COLARDYN,t G E E R T D E S O E T E $ and C O N S T A N T I N J A N N E S §
(Received 5 March 1997; accepted 13 May 1997) Abstract--We evaluated personality change following head injury in 68 patients at 6 months postinjury using the NEO Five-Factor Inventory to assess the five personality dimensions of the Five-Factor Model of Personality. All items had to be rated twice, once for the preinjury and once for the current status. Twenty-eight trauma patients with injuries to other parts of the body than the head were used as controis. For the head-injured group, 63 relatives also completed the questionnaire. The results showed no differences between the ratings of head-injured patients and the ratings of trauma control patients. Both groups showed significant change in the personality dimensions Neuroticism, Extraversion, and Conscientiousness. Compared to their relatives, head-injured patients report a smaller change in Extraversion and Conscientiousness. Changes were not reported on the Openness and Agreeableness scales, by neither the head-injured or their relatives, nor by the trauma controls. © 1997 Elsevier Science Inc.
Keywords: Trauma.
Five-Factor Model; Head injury; NEO Five-Factor Inventory; Personality change;
INTRODUCTION T h e p r o b l e m of personality change has been frequently r e p o r t e d as one of the most persistent p r o b l e m s after h e a d injury, and is often cited as an i m p o r t a n t obstacle to social reintegration later postinjury [1-4]. A t one extreme, there m a y be a subtle awareness on the part of the patient and his close relatives of a m i n o r change in personality. A t the o t h e r extreme, there m a y be a dramatic personality disorder resulting in socially unacceptable b e h a v i o r [3]. T h e question can be raised w h e t h e r the r e p o r t e d personality changes following h e a d injury are universal or only present and striking in a limited n u m b e r of cases. It is also not clear as to w h e t h e r r e p o r t e d personality changes result f r o m structural brain damage, or are m o r e psychologically induced and reflect the attempts of the patient to cope with his disabilities. P r i g a t a n o [4, 5] classified personality disorders after h e a d injury along three b r o a d categories. A first g r o u p of disturbances is considered to be reactionary in nature. E x a m p l e s are anxiety, depression, and irritability. T h e y reflect the struggle of the
Departments of *Neuropsychology, tIntensive Care, SData Analysis, and §Psychiatry, University Gent, Gent, Belgium. Address correspondence to: Engelien Lannoo, Department of Neuropsychology 4K3, University Hospital, De Pintelaan 185, 9000 Gent, Belgium. Tel: +32/9/240.45.88; Fax: +32/9/240.45.55: E-mail: [email protected] 505
506
E. LANNOO et al.
damaged organism to adapt to an environment that no longer takes into consideration limited cognitive skills and physical disabilities. A second set of personality changes are neuropsychologically mediated and flow directly from the neuropathological lesions. Examples are impulsiveness, socially inappropriate behavior, unawareness of deficit, and apparent lack of motivation. A final group of personality disorders existed prior to the onset of the brain injury and are considered to be characterological or premorbid in nature. Examples are obsessive or superorderly behavior, a hard-working attitude, and enjoyment of a dependent role. These variable patterns of personality disturbances following head injury create substantial problems in quantifying and measuring them objectively. Postinjury personality disorders have been assessed in many ways, but little effort has been made to relate this assessment to a conceptual model of personality and personality disorders in general. Some researchers [1, 6, 7] applied the Minnesota Multiphasic Personality Inventory (MMPI). From the MMPI, personality disorder scales were derived [8] to yield a self-report measure of the 11 personality disorders described in the Diagnostic and Statistical Manual of Mental Disorders (DSM-III). However, considerable content biases are found to be inherent in the application of the MMPI in cases of neurologic dysfunction because a number of MMPI items tap areas of dysfunction consistent with the sequelae of neurologic damage [9-11]. Moreover, there are theoretical and methodological problems with the application of the DSM-III in the diagnosis of personality disorders [12-14]. Many of these problems might be resolved by using continuous dimensions instead of discrete categories [15]. Such a dimensional alternative could be provided by the Five-Factor Model of personality (FFM) [16, 17], which is a taxonomy of personality traits in terms of five broad dimensions: Neuroticism, Extraversion, Openness to experience, Agreeableness, and Conscientiousness. There is an emergent and growing consensus suggesting that the FFM is a comprehensive classification of personality dimensions that may be an alternative, conceptually useful framework for understanding personality disorders [18]. No previous research reports have been found on the application of the FFM in the investigation of personality changes following head injury. The present study attempts to examine personality change in patients with moderate to severe head injury by the administration of the Neuroticism-Extraversion-Openness Five-Factor Inventory (NEO-FFI) at 6 months postinjury. The N E O - F F I is a questionnaire designed to operationalize the FFM. To separate head injury-related effects from effects due to the sustaining of a traumatic injury, patients with traumatic injuries to parts of the body other than the head were used as controls.
METHOD Subjects Head injured group. This group consisted of 68 head-injured patients admitted to the intensive care
unit at the University Hospital of Gent during a 30-month period (September 1993 to February 1996). Selection criteria included an admission Glasgow Coma Scale score between 9 and 12 for moderate, and of 8 or less for severe head injury, age between 15 and 65 years, no medical history of central nervous system disease or mental retardation, survival for at least 6 months, and willingness to participate in the study. Of these patients, 63 relatives also completed the NEO-FFI. Trauma control group. This group consisted of 28 patients with injuries to other parts of the body than the head, who were admitted to the intensive care unit during the same study period. Other inclusion
507
Personality change following head injury Table I.--Demographic and medical characteristics
Male/female Age Education (years) GCS TFC (days) PTA (days)
Head-injured
Controls
54/13 35 11 7 15 38
20/8 37 12 15 0 0
GCS: Glasgow Coma Scale; TFC: time to follow commands (coma length); PTA: posttraumatic amnesia.
criteria were age between 15 and 65 years, survival for at least 6 months, and willingness to participate in the study. Patients with evidence of minor head injury (loss of consciousness, amnesia, or facial injuries), and patients with a medical history of central nervous system disease or mental retardation, were excluded. This sample matched the head-injured on gender, age, and education (Table I).
Procedure At 6 months postinjury, patients were administered the Dutch version of the NEO Five-Factor Inventory (NEO-FF1) [19]. This questionnaire measures the five personality dimensions of the FFM: Neuroticism (chronic level of emotional adjustment and instability); Extraversion (quantity and intensity of preferred interpersonal interactions); Openness (active seeking and appreciation of experience); Agreeableness (kinds of interactions a person prefers); and Conscientiousness (degree of organization and control in goal-directed behavior) [18]. It consists of 60 items rated on a five point scale. To assess change since the injury, patients were asked to rate the items twice, once (retrospectively) for their preinjury status, and once for their current postinjury status. Because it is generally assumed that head-injured patients cannot reliably report their own behavioral status due to limited self-awareness and anosognosia [20], a close relative of each head-injured patient was also asked to complete the questionnaire. Comparison of the patient's versus relative's report can provide information on how realistic head-injured patients can evaluate their own behavioral strengths and limitations [21].
Data analysis MANOVA procedures for repeated measures were conducted to examine the differences between the preinjury and current ratings of head-injured patients and their relatives on the five NEO-FFI scales, and to examine the differences between preinjury and current ratings of the head-injured compared to the trauma control group. For both analyses, the raw scale scores were used. Analyses were carried out using SPSS.
Table II.--Means and standard deviations of the ratings of head-injured patients and their relatives on the NEO-FFI Head-Injured Preinjury Neuroticism Extraversion Openness Agreeableness Conscientiousness
17 30 22 32 34
(8) (6) (6) (7) (7)
Relatives
Current 20 29 22 31 32
(9) (6) (6) (7) (8)
Preinjury 16 31 20 32 35
(8) (7) (6) (8) (8)
Current 20 27 20 31 31
(6) (7) (5) (8) (9)
pa
pb
pC
0.000 0.000 0.947 0.091 0.000
NS NS (0.003) J NS NS
0.320 0.007 0.341 0.977 0.003
a Main effect of preinjury vs. current ratings. u Main effect of patients' vs. relatives' ratings. c Interaction effect. a p Value in parentheses because the M A N O V A showed a trend toward significance (p < 0.10).
508
E. LANNOO et al. RESULTS
Table II shows the mean values and standard deviations of the ratings of headinjured patients and their relatives on the NEO-FFI. M A N O V A for repeated measures revealed significant differences between preinjury and current ratings of patients and relatives on the NEO-FFI (Hotelling's statistic=0.618, p<0.001). Subsequent univariate tests yielded significant changes on the scales of Neuroticism, Extraversion, and Conscientiousness, and a trend toward a change on the scale of Agreeableness. Analysis of the raw scale scores showed higher ratings on Neuroticism, and lower ratings on Extraversion, Agreeableness, and Conscientiousness (Fig. 1). There was a trend toward a difference between the ratings of patients and relatives (Hotelling=0.175, p =0.088). Subsequent univariate tests showed a significant difference on the Openness scale, with patients rating themselves higher than their relatives (Fig. 1). There was also a significant interaction effect (Hotelling=0.211, p =0.045). Subsequent univariate tests were significant for Extraversion and Conscientiousness, with patients reporting a smaller change than relatives (Fig. 1). Table III contains the mean values and standard deviations of the ratings of the headinjured and trauma control patients on the NEO-FFI. A MANOVA for repeated measures showed no significant differences between patients and controls on the NEO-FFI (Hotelling=0.059, p=0.383). Both groups report significant differences between preinjury and current status (Hotelling=0.398, p<0.001). Subsequent univariate tests revealed significant differences on Neuroticism, Extraversion, and Conscientiousness. Analyses of the raw scale scores demonstrate higher ratings on Neuroticism, and lower ratings on Extraversion and Conscientiousness (Fig. 2). No interaction effect was found (Hotelling=0.092, p =0.152).
40 30352520 "..... "~j •.....
.'.
[ ] Head Injured Preinjury OHead Injured Current [ ] Relative Preinjury [ ] Relative Current
lO N
E
0
A
C
Fig. 1. Ratings of head-injured subjects and their relatives on the NEO-FFI.
Personality change following head injury
509
Table IlL--Means and standard deviations of the ratings of head-injured patients and trauma controls on the NEO-FFI Head-Injured Current
Preinjury
Neuroticism Extraversion Openness Agreeableness Conscientiousness
17 30 22 31 34
Trauma controls
(8) (7) (6) (7) (7)
20 28 22 31 32
Preinjury
(9) (6) (6) (7) (8)
17 31 24 32 36
(8) (4) (6) (4) (5)
Current 21 28 24 31 35
(10) (5) (6) (5) (6)
p~
pb
pc
0.000 0.000 0.782 0.396 0.009
Ns NS NS us US
NS NS NS NS NS
a Main effect of preinjury vs. current ratings. b Main effect of head-injured vs. trauma control ratings. c Interaction effect.
DISCUSSION
The results indicate that head-injured patients report a significant change in personality at 6 months postinjury, but fail to demonstrate any difference between head-injured patients and patients with traumatic injuries to other parts of the body than the head. Compared to preinjury ratings, both groups reported higher ratings on the Neuroticism scale, and lower ratings on the Extraversion and Conscientiousness scales of the NEOFFI. The lack of difference between both groups suggests that the reported personality change might be reactionary in nature, reflecting the attempts of the patients to cope with their disabilities, whether these are related to structural brain damage or to other system injuries. However, it remains possible that head-injury-related personality
ii 30 [ ] Head Injured Preiniury [ ] H e a d Injured Current 25
E~ Controls Preinjury I~! Controls Current
20
15
10 N
E
0
A
c
Fig 2. Ratings of head-injuredsubjects and trauma controls on the NEO-FFI.
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changes present in head-injured patients and not in control patients might not have been measured by the NEO-FFI. When the preinjury and current ratings of head-injured patients and their close relatives on the NEO-FFI were compared, we found an interaction effect. Relatives report a greater change on the Extraversion and Conscientiousness scales than the patients. This suggests that patients tend to underestimate the degree of personality change. However, patients do not seem to be totally unaware of these changes, nor do they deny them, because they also report a change on these scales, but to a lesser degree than do their relatives. However, the control group did not have relatives who were assessed, and it may be that the observed differences between head-injured patients and their relatives also occur in trauma control patients and are in fact unrelated to the head injury. Changes are not reported on the Openness and Agreeableness scales of the NEOFFI, neither by the head-injured patients and their relatives nor by the trauma control patients with other system injuries. On the Openness scale, however, headinjured patients tended to rate themselves higher than do their relatives, both for their preinjury and postinjury status. Whether this trend toward a difference on this scale is typical for head-injured patients, or more universal in the sense that self-reports on this scale always tend to be higher than the ratings of significant others, warrants further investigation. Little information is available on the stability of the personality dimensions of the FFM over time. It can be hypothesized that some of the personality dimensions are prone to change, especially in case of a traumatic life event, whereas others tend to be more stable over time. Our findings are indicative of changeability on the Neuroticism, Extraversion, and Conscientiousness scales, and a stability on the Openness and Agreeableness scales of the NEO-FFI. However, because the reports of the preinjury status were retrospective, and because of the limited time interval between preinjury and current status, these results should be viewed as hypothesis generating and in need of future corroboration, not only in head-injured patients, but also in normal populations and after other significant life events. In conclusion, our findings indicate that traumatic injuries are followed by a change in personality that is probably reactionary in nature. These changes occur in the domains of Neuroticism, Extraversion, and Conscientiousness of the FFM. However, compared to their relatives, head-injured patients tend to underestimate the degree of change.
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