Tonic arousal and activity: Relationships to personality and personality disorder traits in panic patients

Psychiatry Research. 25,672

65

Elsevier

Tonic Arousal and Activity: Relationships to Personality and Personality Disorder Traits in Panic Patients Roy J. King,

E. Paul Bayon,

Duncan

B. Clark,

and C. BarrTaylor

Abstract. Personality theorists have long predicted a relationship between personality traits and autonomic activation. In this study, 4X patients with panic disorder underwent personality assessment by questionnaire (Eysenck Personality Inventory: 4X patients) and by interview (Personality Disorders Examination: 35 patients). Ambulatory heart rateand activity were measured by the Vitalogmethod and were used as measures 01 activitation and autonomic arousal. There was a significant positive correlation between histrionic traits and activity level and a significant negative correlation between sociability and heart rate.‘l’hefindingsare consistent with previous studies showinga negative relationship betweensensationseeking personality traits and cerebrospinal fluid levels of norepinephrine and a positive relationship between extroversion and cerebrospinal fluid levels of dopamine. Key Words. Theories personality

Arousal,

of arousal traits

histrionic

predicting

have

a long

personality,

sociability,

activity

associations

between

autonomic

activation

and

history

in personality research. Eysenck (1967) proposed that introverts should manifest heightened cortical arousal and, by implication, show features of facilitated avoidance learning. This model has been elaborated upon by Gray (1970, 198 I), who hypothesized that neurotic introverts or anxious individuals have a hyperresponsive behavioral inhibition system that inhibits reward-seeking behavior in the presence of cues signifying nonreward or punishment. Much of the data in the literature is in partial support of either of these two propositions. It has been noted (Gale, 1973), however, that the experimental situation may co-determine levels of arousal in an interactive fashion with extroversion. For example, extroverts often show low arousal in vigilance tasks but may show a heightened arousal while performing more activating tasks involving incentives. Another series of hypotheses and findings concerns the construct of sensation seeking and its relationship to arousal (Zuckerman et al., 1980). This work suggests that sensation seeking involves a heightened arousal-seeking trait. In a study relating a cerebrospinal fluid (CSF) measure of central catecholamines and their metabolites,

Koy J. King. M.D., Ph.D.. ia Assistant PI-ofesaorof’Psychiatry;E. PaulBayon~s KesearchAsstatant;Uuncan B. Clark. M.D.. Ph.D.. IS Postdoctoral Fellow; and C. Barr l.aylor, M.D., is Associate Professor of Psychiatry, Dcpartmcntof’Psychiatryand BehaworalSclences,Stanf’ord Umversity,Stanf’ord,CA.(Keprint requests to Dr. K.J. King. Dept. of Psychiatry and Behavioral Sciences, Stanford University, Stanford. CA Y4305. USA.) 01651781/88/%03.50

@ 1988 Elsevier Scientific

Publishers Ireland

Ltd.

66 Ballenger et al. (1983) found a negative correlation between CSF levels of norepinephrine and self-report sensation-seeking measures in normal subjects. This result suggested that sensation-seeking individuals manifest relatively low arousal under the conditions of the spinal tap. As the collection and analysis of human CSF presents a number of practical and technical problems, a noninvasive indicator of physiological arousal would be useful. Tonic heart rate may serve as such an indicator. Although several theories concerningthe relationship betweenarousaland personality have been proposed, few models of the relationship between locomotor activity and personality have been offered. Garcia-Sevilla (1984) has suggested that the human analog of rodent open-field activity was extroversion, while King( 1986) theorized that activity, mesolimbic dopamine levels, and personality styles like extroversion and histrionic personality traits would interrelate. More specifically, it was predicted that individuals with histrionic or extroverted traits would show enhanced motor activity to incentives, as a consequence of an increased dopamine neuronal activity. Several studies have supported the implications of these theories. An automated motor activity measure in children showed a strong correlation between activity and energetic, restless, attention-seeking, and emotionally expressive behaviors sampled both concurrently and up to 4yearsaftertheactivity recording( Russet al., 19BO). Adult extroverts show a heightened verbalactivity( Ramsay, 1966; Rutteretal., 1972). Kinget al. (1986) showed that in male subjects with current major depressive disorder, CSF levels of dopamine and a self-report measure of extroversion from the Eysenck Personality Inventory indeed did correlate significantly. To summarize, both extroversion and histrionic personality traits have been hypothesized to be correlated with motor activity, but the technology to measure motor activity over long periods has not been used in this context. One of the criticisms of biologically based personality theories is that situationally and temporally limited measures of behavior often show low correlations with selfreport personality questionnaires (Mischel, 1968). However, averaging over multiple time points and over many situations can lead to an improvement in the correlations between behavior and traits assessed by personality inventories (Epstein, 1977). To overcome this problem, we used a device that allowed us to measure heart rate and activity continuously, averaging over multiple situations during a single day in naturalistic, nonlaboratory settings.

Methods Patients. Seventy-six subjects were recrulted to participate in a study comparing the efficacy ol medication treatments for panic disorder and agoraphobia. .I he patients were interviewed by trained clinicians using the Structured Clinical Interview for Diagnosis (Upjohn version: Spitrer and Williams, 1983). Inclusive diagnoses were panic disorder without phobic avoidance. panic disorder with limited phobic avoidance, and panic disorder with extensive phobic avoidance (agoraphobia). Patients underwent a variety ofmedical examinations. Routine blood chemistq assays were obtained. Patients who were pregnant or lactating, had histories ofsellures or head trauma with unconsciousness, a history of alcoholism or substance abuse, or medical illnesswjere excluded from the study. All patients were requested to be drug free forat least 2 weeks before the heart rate and activity monitoring. These patients were screened for benlodia/epineb through a blood test. After completing the medication treatment. the patients were asked to return iora t‘ollouup interview to assess their current functioning as w,ell as to undergo B battery ol pcrhonalit! tat

67 interviews. Forty-eight (12 males and 36 females) of the 76 subjects agreed to at least a written personality test that was mailed to the individuals, while 35 of these 48 subjects consented to an indepth clinical interview assessing DSM-/II-K Axis II personality disorder traits (Loranger et al., 1987). The mean interval between the Vitalog recording of heart rate and activity and the assessment ofpersonalitywas41 weeks.withamedianof33 weeksandarangefrom22weeksto76 weeks. The mean age of the subjects was 37.7 (SD 9.8) years. Heart Rate and Activity Assessment. After the initial screening for the diagnosis of panic disorder, patients worea Vitalog MC-2 Monitorforupto3daysand nights.Thisdevicemeasures the level of activity and heart rate during the monitoring period. The MC-2 is a solid state microcomputer which measures 4 x 8 x I2 cm, weighs 0.5 kg, and is worn on the belt. A motion sensor, which consists of six liquid mercury switches aligned on the faces of a cube, is attached to the lateral thigh. Physical activity was categorized to eight levels representing a total number 01 activations of the mercury switch over each I-min sample. The total number of heartbeats, min during I-min periods was stored in I of 64 categories, each representing 2 beats; min over a range of 40-160 with two additional categories for heart rates <40 and for heart rates 2161. When contact of the electrodes used in heart rate sensing failed, a heart rate of 0 was recorded. These periods were eliminated from the analysis by a command in the statistical computer program. At the end of the data collection, the memory was loaded into a minicomputer for storage and analysis. The average daily heart rate (H R), average daily activity, and sleep heart rate (sleep HR) were determined by averaging the min x min total HR and activity for waking and sleep periods. Waking and sleep periods were determined by activity level. Comparison of the results of this categorization method with self-report from diaries validated this method. A sleep period was defined as a minimum of a 4-hour period between the hours of IO:00 p.m. and IO:00 a.m., beginning with a drop in activity to one activity level unit or below fora minimum of I hour. After this initial hour, all IO-min intervals with any activity over one unit were excluded from the sleep period. The sleep period was defined as ending when activity rose to over one unit for one-halfor more of the IO-min intervals in an hour. A waking period was defined as a minimum of a 4-hour period between the hoursof6:OOa.m. and 12:OOmidnightbeginningwithanincreaseinactivityto two activity units or moreforat least one-half ofthe IO-min periods fora minimum of2 hours, l’he waking period was defined as ending when the record met the criteria for sleep. One waking and one sleep period wereanalyzed for each subject. Where possible, the analysis began with the first slerpperiod,with thefollowingwakingperiod beingusedinmostcasessothat.foragivensubject. the data came from the same 24-hour perrod. For the subjects who had received placebo, the X-weekretestreliabilitycorrelationsforwakingHR(n=l7).sleepHR(~~=l8).andactivity(n=l6) were 0.70.0.69, and 0.73, respectively. Personality

Assessment. All 48 subjects who responded to the followup request received the Eysenck Personality Inventory (EPI) (Eysenck and Eysenck. 1964). The inventory was scored for the sociability and impulsivity subscales (Revelle et al., 19X0), as well as for neuroticism and lie scales. Of these 48 subjects, 35 were brought in for a structured clinical interview assessing personality disorder trarts. The instrument, the Personality Disorders Examination (PDE) (Loranger et al., 1987) assesses the severity of each of the I I DSM- I//-K Axis II personality disorders. In a larger sample of patients and controls from this group (n q 170). histrionic and avoidant traitsdemonstratedgoodinternalconsistency(Cronbach’scr=0.75forbothtraits). Moreover,the interrater reliabilities for histrionic and avoidant traits were high (intraclass I q 0.95 and 0.99. II = 21, respectively). Finally, the retest reliability correlations for a sample of24 subjects tested an average of32 weeks apart were 0.82 for htstrionic traits and 0.68 for avoidant traits. ‘l’hepersonalityassessment,aswellastheanalysisoftheVitalogdata,wasdoneindependently. Experimenters were unaware of each other’s results. Pearson’s product-moment correlations were used to assess the correlations and, where appropriate, partial correlations were obtained from the data set.

68 Hypotheses. Eysenck’s and Gray’s hypotheses, to oversimplify somewhat. postulate that subjects high in sociability and impulsivity have low arousal. We therefore predicted that sociability and impulsivity would be negatively correlated with tonic HR. Similarly, as avoidant traits are proposed to signify high arousal, we predicted a positive correlation between avoidant traits and tonic HR. King’s ( 1986) hypotheses suggest that extroverted and histrionic individuals are high in motor activity. We therefore predicted that sociability, impulsivity, and histrionic traits would be positively correlated with activity.

Results 1 lists the sample means for the panic patients and a group of control community volunteer subjects with a mean age of 33.3 (SD 13.3) years. Note that the panic patients are significantly more avoidant, borderline, and neurotic, and significantly lesssociable than controls. The group with panicdisorders had a mean waking HR of 87.9 (SD 9.0) bpm(n=48),ameansleepHRof66.7(SD8.7)bpm(n=47),andameandailyactivityof 2.46 (SD 0.87) countsimin (n = 46). Although psychophysiological results are not available for the control sample receiving the personality examinations, these values do not differ significantly from those of a separate control group (Taylor et al., 1987). Table 2 shows the correlation between waking H R and activity from the Vitalog with the hypothesized PDE Axis II severity scores and the Eysencksubscalesforthesubjects with panic disorder. As can be seen, there was a significant negativecorrelation between HR and sociability. In addition, there was a significant correlation between histrionic Table

Table 1. Comparison of means (2 SD) between panicdisordered patients and control subjects on personality Personality traits1

Panic patients

Control subiects

Paranoid

PDE 1 \ PDE) Schizotypal (PDEI

5.024.0

3.7 i 4.4

Schizoid

3.8 t 5.2

2.553.8

10.7 I? 9.1

7.7 i 7.3

Compulsive

10.6 I 6.5

10.2 i 5.8

(PDE)

Histrionic

PDE’

7.3 + 4.8

7.3 2 6.6

Dependent

1PDE,

6.5 I 5.1

4.8 f- 4.4

I PDEI ( PDEl

8.4 2 7.3

5.2 2 6.8

7.025.9

6.4 i 4.9

Anttsocial Narcissistrc

(PDEI Borderline ( PDEI

Avoidant

Passive-aggressive Sociabrlrty

EPI

lmpulsrvity

(EPI )

Neurotrcism Lre EPI

(EPI)

t PDE!

9.9k7.3

5.32 4.23

13.6i9.9

9.2? 8.22

4.913.5

4.0 -t 3.2

5.9 i 3.0

7.2 I 3.02

3.9 i 2.0

3.9 i 1.8

12.7 i 5.9

6.8 + 4.54

2.6~ 1.5

2.7 + I.8

traits

1, PDE Personality Disorders Examlnatlon. EPIL Eysenck PersonaMy Inventory. Forthe PDE variables, sample swes are 35 for the patlent group and 42 for the control group. while for the EPI variables, sample snes are 48 pabents and 43 controls 2. p c 0 05. Z-talled f test. 3 p.- 0.005. Stalled f test 4 0’ 0 001. Stalled t test

69 Table 2. Planned analyses Trait

Waking heart rate

n

Sociability

(EPI I

-0.261

48

lmpuhvity

EPI!

-0.11

48

0.07

35

Avoldant

~PDEI

Trait Sociability lmpuhvity Histrlonlc

/ EPI, I EPI I (PDEI

Note. EPI Eysenck Disorders Examlnatton.

Personality

Activity

n

-0.05

46

0.02

46

0.352

33

Inventory

PDE = Personaltty

1.p - 0.05, 1-talled Pearson’s 2. p L 0.025. 1-talled Pearson’s traits and activity levels. Heart rate and activity in this sample were positively correlated. When a partial correlation coefficient controlling for level of activity was calculated, HR and sociability remained significantly associated (1. = -0.26, n = 48,p< 0.05. one-tailed). To control for the severity of illness, a multiple regression analysis was performed usingillnesscategory(uncomplicated, limitedphobicavoidance,andagoraphobia)and the sociability scores as predictors for HR. When diagnosis was controlled for, sociability retained significance as a predictor of H R (F~4.40; ~//!f-I ,44;p
Discussion These results indicate that within a sample of individuals without anxiety disorder, social introversion is associated with high levels of autonomic arousal, and histrionic traits are linked to high levels of motor activity. Neither of these two relationships appears explainable by differences in levels of phobicavoidance. Compared to a sample of control subjects, panic patients are more avoidant, more neurotic, and less sociable, but they do not differ in their level of histrionic traits--results similar to those of Mavissakalian and Hamann (1986). Thus, the relationship between this index of cardiac arousal and sociability could be a result of the subjects having an anxiety disorder that in a subgroup leads to a perception of social aversiveness. This is in

70 Table 3. Post hoc correlations Vitalog measures

of personality

traits with

Waking HR

Sleeping HR

Activitv

t PDE

0.07

-0.15

0.07

Schlzold \PDEI

-0.10

-0.23

0.06

0.06

-0.16

0.08

0.00

-0.02'

.07

-0.10

-0.36'

-2

Trait Paranoid

8, PDE’ / PDE)

Schlzotypal Compulsive

(PDE,

Hlstrionlc Dependent AntIsocial Narclsslstlc Avoidant

PDE

0.13

0.24

PDE)

-0.18

-0.38'

0.28

-0.04

-0.19

0.29

PDE’

, PDE’

Borderline

(PDE

Passive-Aggressive Soclabillty

EPI

lmpulslvlty

, EPI

Neuroticism

PDE)

1

EPI

Lie :EPI Note. HR Personality

heart rate PDE Inventory

0.26

--2

-0.02

0.16

-0.01

-0.11

0.20

-0.08

0.00

0.06

--2

-0.18

--L

-2

-0.09

-1

-0.05

0.03

0.03

0.06

0.13

Personality D&orders Examlnatlon

0.13 EPI

Eysenck

1. p L 0.05, 2-talled Pearson’s 2. See Table 2 for planned analyses For this table. the correlations of the PDE variables had sample sues of 35 with waking HR. 34 w!th sleep HR, and 33 with actlvlty The correlations of the EPI variables had sample sizes of 48 with wakmg HR and 46 with both sleep HR and activity

with the childhood data of Kagan et al. (19X7), who showed that extremely cautious, shy children showed longitudinally stable signsofautonomicarousal across a number of situations. Whether this elevated arousal is a temperamental bias or a disease state (anxiety disorder) remains a critical question to be answered. In this study, the average length of time between the Vitalog recording and the personality assessment was >40 weeks, indicating some temporal stability to the finding. The results of this study are consistent with both Eysenck’s and Gray’s models. as the introverted patients showed higher arousal and panic patients were also relatively high in neuroticism compared with controls. Although factors that influence H R such as physical fitness and activity may mediate the relationship between introversion and HR, in this study, controlling for the levels of daily activity did not reduce the association between introversion and elevated tonic HR. The findings of this study are more specifically in agreement with the results of Ballenger et al. (1983). who showed a relationship between sensation-seeking traitsand a presumptive measure of central arousalLCSF levels of norepinephrine. The counterpartofaheightenedawarenessofdangerorriskisalackofsensation-seekingtraits, both perhaps operating at a cognitive level involving the internal calculations of dangerousness of multiple stimuli. The association between histrionic traits and activity may reflect a propensity for histrionic individuals to initiate interpersonal action. Attention-seeking behavior may agreement

71

be a dominant mode of activity for the socially active primates. This result agrees with the work of Buss et al. (1980), who found that attention-seeking traits were correlated with activity measured by an actometer in school-aged children. The lack of a correlation between extroversion and activity may be explainable by the evidence that in this anxious sample much of the variance in introversion is related to elevated autonomic arousal rather than to differences in general activity. Whether the relationship between histrionic traits and activity is due to normal variations in both traits or due to a psychopathological condition such as “attention deficit disorder, residual type”(Wender etal., 198 1)again isan important issue. Dienske et al. (1985) showed that among control children, hyperactivity was not related to attentional problems but, among child patients, hyperactivity was correlated with inattention. Thus, patient and control populations may differ in their clustering of behavioral and physiologicalmeasures. Thepost hocnegativecorrelation between both histrionic and antisocial traits and sleep HR is curious and needs to be replicated using all night sleep recording of sleep stages and autonomic measures. It is consistent, however, with Cloninger’s (1987) model of histrionic/antisocial traits reflecting low harm-avoidance as well as high novelty-seeking activity. Also, Fowles (I 980) has presented a model of sociopathy that postulates low tonic electrodermal arousal, coupled with a high phasic H R and motor activity in psychopaths. Since sleep H R may reflect basalautonomicactivityintheabsenceofexternalincentives,theposthocresults offer a direction for future studies along these lines. This study indicates that experiments monitoring subjects in naturalistic settings over long periods of recording time may be useful in exploring the validity of various theories about the relationship between personality and neurobiology. Usingthe Vitalogdevice, the continuous measurement of tonic HR as an indicator of arousal and activity, as an indicator of exploratory behavior overcomes a number of methodological problems that have limited this area of personality research. Acknowledgments. This work was supported by grants from the Robert Wood Johnson Foundation, Upjohn Corporation, and a postdoctoral training grant from NI M H (MH-16744).

References Ballenger, J.C., Post, R.M., Jimerson. D.C., Lake, C.R., Murphy, D.L., Zuckerman, M., and Cronin, C. Biochemical correlates of personality traits in normals: An exploratory study. Per.wnalif_v and Individual Dlyferences. 4,6 15 ( 1983). Buss, D.M., Block, J.B., and Block, J. Preschool activity level: Personality correlates and developmental implications. Child Development, 51,401 (1980). Cloninger, C.R. A systematic method for clinical description and classification of personality variants. Archives of’General P.sychiarry, 44,573 (1987). Dienske, H., DeJonge, G., and Sanders-Woudstra, J.A.R. Quantitativecriteria forattention and activity in child psychiatric patients. JournaloJ’Child P.ycho/ogy and P.s~l~chiarr~r~, 26,895 (1985). Epstein, S. Traits are alive and-well. In: Magnuson, D., and Endler, N., eds. Persona/it.l, a/ the Crossroads: Current Issues in lnrernational Ps,~cholog~l. Lawrence Erlbaum, Hillsdale, NJ ( 1977). Eysenck, H.J. The Biological Basis oj’Per.wna/it~~. Charles CThomas, Pubhsher, Springfield, IL(1967). Eysenck, H.J., and Eysenck, S.B.G. Manualof’rhe E~wnck Personalit), Inventor!,. University of London Press, London ( 1964).

72 Fowlcs, D.C. ‘l-he three-arousal model: Implications of Gray’s two-factor learning theory for heart rate, electrodermal activity and psychopathology. Ps,,c,ho~h?,sio/og?,, 17,87 ( 1980). Gale, A. The psychophysiology of individualdifferences: Studiesofextroversionand the EEG. In: Kline, P., ed. Nen, Approaches in f.s.whologicd Meusuren~en~. Wiley, New York (1973). Garcia-Sevilla, L.I. Extroversionand neuroticism in rats. Per.sonalir~~und/ndividuu/L)~~eren(‘e.\. 5, 511(1984). Gray, J A. The psychophysiological basis of introversion-extroversion. Behutiour Re.\eurch und Therap),, 8,249 (1970). Gray, J.A. A critique of Eysenck’s theory of personality. In: Eysenck, H.J., ed. A Mode/,/Lw Prr.sonu/if~. Springer, Berlin ( I98 I). Kagan, J., Reknick, J.S., and Snidman, N. The physiology and psychology of behavioral inhibition in children. Child Doveloprnenr, 58, 1459 (1987). King, R. Motivational diversity and mesolimbicdopamine: A hypothesisconcerning temperament. In: Plutchik, R., and Kellerman, H., eds. En~orion: Theor,,, Re.seurc,h and Experience. Biologicul Foundufions qf’Emorion.s. Vol. 3. Academic Press, Orlando, FL (1986). King, R.J., Mefford, I.N., Wang, C., Murchison. A., Caligari, E.J., and Berger, P.A. CSF dopamine levels correlate with extroversion in depressed patients. P~swhiarr.t~ Re.srarch, 19,305 (1986). Loranger,A.W..Sussman,V.l~.,Oldham,J.M..andRossakoff,L.M.Thepersonal~tydisorder examination: A preliminary report. Journul of’Per.sonu/it~~ Disorders, I, I (1987). Mavissakalian, M., and Hamann, M. L)SM-IIIpersonalitydisorderinagoraphobia. Cor77pvrhmsivr P.sJ,chiutry. 27,47 I ( 1986). Mischel, W. Per.sonalit~* and A.s.se.s.sn~ent. Wiley, London ( 1968). Ramsay, R.W. Personality and speech. Journul qf’Per.wnulit~~ und Social P.s.rcholog,~. 4, II6 (1966). Revelle, W., Humphreys, M.S., Simon, L.. and Gilliland, K. The interactive effect 01 personality, time of day and caffeine: A test of the arousal modes. Journal of’ E.rperinwnful P.syho/ogyc Gmerul, 109, I ( 1980). Rutter, D.R., Morley, I.E., and Graham, J.C. Visual interaction in a group of introvertsand extroverts. European Journal oj’Swiu/ P.syho/ogv, 2,37 I (1972). Taylor, C.B., King, R.J., Ehlers, A., Margraf, J., Clark, D., Hayward, C., Roth, W.T., and Agras, S. Treadmillexercise test andambulatorymeasures inpanicattacks. American Journalof Curdiologr,,

60,485

(1987).

Wender, P.H., Reimherr, F.W.. and Wood, D.R. Diagnosisand treatment ofattentiondeficit disorder (minimal braindysfunction) inadults: A replication. Archive.sof’Generul P.svchiutr,~, 38, 449 (1981).

Zuckerman, M., Buchsbaum, M.S., and Murphy, correlates. P.~~~cho/ogicul Bulletin, 88, I87 ( 1980).

D.L. Sensation

seeking and its biological