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ADOLESCENTS’ EXPOSURE TO COMMUNITY VIOLENCE: SLEEP AND PSYCHOPHYSIOLOGICAL FUNCTIONING Michele Cooley-Quille Johns Hopkins University Raymond Lorion Ohio University The relationships among psychophysiological indices, sleep disturbance, and adolescents’ exposure to community violence were examined in a pilot study of 64 community youth (ages 16 –18; 84% African American), 25 of whom had their blood pressure and pulse rates assessed. Neither age nor gender differences were found in self-reported sleep disturbance or community violence exposure. Self-reported exposure to community violence and sleep deprivation were positively related. Multivariate analyses of covariance (MANCOVAs) revealed that youth at the highest of three levels of violence exposure had the lowest resting pulse rates. These results suggest that youth in communities marked by pervasive violence may be physiologically adapting and emotionally desensitizing to that violence. Implications for intervention are discussed. © 1999 John Wiley & Sons, Inc. This project was designed as a preliminary examination of presumed relationships among exposure to community violence, sleep patterns, and physiological response pat- terns. Numerous reported studies of urban youth have documented the nature, extent, BRIEF REPORT JOURNAL OF COMMUNITY PSYCHOLOGY, Vol. 27, No. 4, 367–375 (1999) © 1999 John Wiley & Sons, Inc. CCC 0090-4392/99/040367-09 This work was undertaken by the Hopkins Prevention Research Center with support from the National Insti- tute of Mental Health (Epidemiologic Center for Early Risk Behaviors, Grant 2 P300 MH 38725-11). The au- thors would like to thank the co-investigators of the HPRC Assessment Core Pilot Study for their contributions to the project. Correspondence to: Michele Cooley-Quille, Ph.D., Department of Mental Hygiene, School of Hygiene and Public Health, Johns Hopkins University, Hampton House, 8th Floor, 624 N. Broadway, Baltimore, MD 21205.

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Page 1: Adolescents' exposure to community violence: Sleep and psychophysiological functioning

ADOLESCENTS’ EXPOSURE TO COMMUNITY VIOLENCE:SLEEP ANDPSYCHOPHYSIOLOGICALFUNCTIONING

Michele Cooley-QuilleJohns Hopkins University

Raymond LorionOhio University

The relationships among psychophysiological indices, sleep disturbance, andadolescents’ exposure to community violence were examined in a pilot studyof 64 community youth (ages 16–18; 84% African American), 25 of whomhad their blood pressure and pulse rates assessed. Neither age nor genderdifferences were found in self-reported sleep disturbance or communityviolence exposure. Self-reported exposure to community violence and sleepdeprivation were positively related. Multivariate analyses of covariance(MANCOVAs) revealed that youth at the highest of three levels of violenceexposure had the lowest resting pulse rates. These results suggest that youthin communities marked by pervasive violence may be physiologicallyadapting and emotionally desensitizing to that violence. Implications forintervention are discussed. © 1999 John Wiley & Sons, Inc.

This project was designed as a preliminary examination of presumed relationshipsamong exposure to community violence, sleep patterns, and physiological response pat-terns. Numerous reported studies of urban youth have documented the nature, extent,

B R I E F R E P O R T

JOURNAL OF COMMUNITY PSYCHOLOGY, Vol. 27, No. 4, 367–375 (1999)© 1999 John Wiley & Sons, Inc. CCC 0090-4392/99/040367-09

This work was undertaken by the Hopkins Prevention Research Center with support from the National Insti-tute of Mental Health (Epidemiologic Center for Early Risk Behaviors, Grant 2 P300 MH 38725-11). The au-thors would like to thank the co-investigators of the HPRC Assessment Core Pilot Study for their contributionsto the project.

Correspondence to: Michele Cooley-Quille, Ph.D., Department of Mental Hygiene, School of Hygiene and Public Health, Johns Hopkins University, Hampton House, 8th Floor, 624 N. Broadway, Baltimore, MD21205.

Page 2: Adolescents' exposure to community violence: Sleep and psychophysiological functioning

and emotional and behavioral correlates of exposure to pervasive community violence(e.g., Lorion, Brodsky, & Cooley-Quille, 1999; Singer, Anglin, Song, & Lunghofer, 1995).Research conducted during the past decade has established the importance of this prob-lem for child health and development. Across multiple settings and methods to assessexposure and its sequella, investigators have consistently found distressingly high levelsof exposure for many youth and linked such exposure to heightened levels of self-reported anxiety, depression, and other stress-related affective states (Lorion et al., 1999;Gutterman, Cameron, & Staller, in press). Recent reports also link such exposure to cog-nitive and attentional impairments as well as involvement in aggressive and antisocial be-haviors (e.g., Saltzman, 1996; Singer et al., 1995).

Findings to date raise questions about other parameters of functioning that may beinfluenced by exposure to violence and may themselves influence affect and behavior.Based on clinical experience, anecdotal reports of parents, teachers, and exposed chil-dren, the investigators speculated that exposure would also impact sleep patterns andbasic physiological processes. Sleep deprivation has long been associated with attention-al lags, deficient impulse control, and impaired problem-solving (Armsworth & Holaday,1993; Carskadon, 1990; Morrison, McGee, & Stanton, 1992). If such impacts and theirsequella can be documented, they may identify mechanisms underlying the aforemen-tioned cognitive, emotional, and behavioral correlates of exposure. Understanding bothsets of links may inform treatment and preventive interventions. Alternatively, ignoringsleep loss and other physiological parameters of community violence exposure may re-duce the potential effectiveness of these interventions.

This pilot study was also designed to test the feasibility of obtaining informationabout exposure and other parameters of functioning with increased efficiency. As ex-plained below, existing measures were re-formatted for computerized administration andrecording of answers, a format that may offer a means of collecting sensitive informa-tion with reduced intrusion.

METHODS

Procedure

The pilot study was conducted at the Hopkins Prevention Research Center (HPRC). Af-ter obtaining parental consent and youth assent for study participation, interviews wereconducted with individual respondents using laptop computers. Questions were dis-played on the computer screen. Depending on the participant’s choice, responses wereentered using a mouse by either the respondent him/herself or by a trained interview-er whose race and gender matched the respondent’s. Fifty-eight of the 64 interviews wereconducted at the HPRC; the remaining six were administered at the respondents’ home.The entire interview lasted approximately 2.5 hours; measures unrelated to the focus ofthis report (e.g., racial socialization, religious involvement, social competence) are notpresented herein. Time and resource limitations restricted collection of physiologicaldata to 25 consecutive respondents.

Participants

The targeted community sample included 250 urban youth, aged 16 to18, who had pe-riodically participated in HPRC research projects. Of these, 72 were interviewed; com-plete data on exposure to community violence and sleep patterns were available for 64

368 • Journal of Community Psychology, July 1999

Page 3: Adolescents' exposure to community violence: Sleep and psychophysiological functioning

youth, 40 of whom were female. The mean age of the 64 adolescents was 16.84 (SD 50.70; range 5 16–18). The 26% response rate reflected the loss of some families who re-fused to participate and (the majority) whose addresses and phone numbers were out-dated. Of the 64 participants, 54 (84%) were African American, 1 (2%) was Native Amer-ican, 5 (8%) were Caucasian, and 4 (6%) identified themselves as “other.” No statisticallysignificant differences were found on demographic, community violence, or sleep vari-ables between the 64 youth and the 25 for whom psychophysiological data were available.

Measure s

Community violence. The Children’s Report of Exposure to Violence (CREV; Cooley, Turn-er, & Beidel, 1995) is a 29-item self-report questionnaire designed to assess children’s ex-posure to community violence, defined as deliberate acts intended to cause physicalharm against persons in the community. Responses are made on a 5-point Likert scaleassessing the frequency of lifetime exposure through various modes (i.e., media, hearsay,directly witness, or directly experience). Violent situations include being chased orthreatened, beaten up, robbed or mugged, shot, stabbed or killed. The Total CREV score represents a sum of the responses. The CREV has acceptable 2-week test-retest reliability (r 5 .75), internal consistency (Cronbach’s alpha 5 .78), and construct validi-ty (Cooley et al., 1995). The questions, response choices, and scoring for the computer-ized CREV were identical to the paper-and-pencil version; preliminary evidence of in-ternal reliability (Cronbach’s alpha 5 .93) exceeds that of the paper and pencil version(Cooley et al., 1995).

Sleep disturbance. Youth reported their sleep difficulty over the previous week on a 5-itemquestionnaire (e.g., During the past 7 nights, how many times have you had troublefalling asleep?) developed specifically for this pilot study. Responses were reported on a5-point Likert scale; higher scores reflected increased difficulty sleeping.

Psychophysiological arousal. Psychophysiological arousal was assessed via measures of bloodpressure and pulse rate. Participants were asked not to smoke at least 2 hours prior totheir interview. An automatic pulse-rate monitor/electrosphygmomanometer was used.The arm cuff appropriate for the subject’s size was placed on the non-dominant arm inline with the brachial artery and humerus. Participants were instructed not to speak ormove that arm while the cuff inflated or deflated. Inflation ranged between 150–180mmHg/sec; deflation rate was 2 mmHg. After a test reading, the participant sat quietlyand relaxed during a 5-minute “adaptation” period followed by a baseline period inwhich four blood pressure and pulse rate readings were taken at 1-minute intervals. Dur-ing the interview, readings were taken at 5-minute intervals. For this study, the mean values of the first 3 readings taken during the Baseline and Interview periods were calcu-lated resulting in six measures: Baseline systolic; Baseline diastolic; Baseline pulse rate;Interview systolic; Interview diastolic; and Interview pulse rate.

RESULTS

Sex and Age Differences

There were no significant gender or age differences in exposure to community violence.This was found for exposure operationalized as a continuous (i.e., Total CREV score) or

Psychophysiology, Sleep, and Community Violence • 369

Page 4: Adolescents' exposure to community violence: Sleep and psychophysiological functioning

Tabl

e 1.

Zer

o-O

rder

Cor

rela

tion

s an

d D

escr

ipti

ve D

ata

Vari

able

Slp

2B

-S 3

B-D

4B

-P 5

I-S 6

I-D 7

I-P 8

NM

(SD

)R

ange

1.a

Com

mun

ity

Vio

len

ce0.

362

0.22

0.31

20.

192

0.15

20.

062

0.22

6248

.50

17.2

713

,99

2.a

Slee

p D

istu

rban

ce—

0.08

0.37

b2

0.21

0.03

0.03

20.

3163

5.89

2.51

1,15

3.B

asel

ine—

Syst

olic

—0.

57**

0.67

**0.

88**

0.57

**0.

2925

115.

0420

.25

35,

150

4.B

asel

ine—

Dia

stol

ic—

0.29

0.72

**0.

68**

0.01

2568

.30

11.0

251

,10

05.

Bas

elin

e—Pu

lse

Rat

e—

0.59

**0.

330.

65**

2576

.41

14.5

635

,10

46.

Inte

rvie

w—

Syst

olic

—0.

82**

0.34

2512

0.08

13.0

285

,15

57.

Inte

rvie

w—

Dia

stol

ic—

0.17

2579

.13

14.4

960

,12

48.

Inte

rvie

w—

Puls

e R

ate

—25

78.1

210

.50

63,

99

Not

e:Pa

rtia

l cor

rela

tion

s w

ere

cond

ucte

d w

ith

psy

chop

hys

iolo

gica

l var

iabl

es (

cont

rolli

ng

for

sex)

, N =

22.

a Oth

ers

wer

e bi

vari

ate

corr

elat

ion

s, N

= 5

6.b.1

0 ,

p.

.05;

*p

,.0

5; *

*p,

.01.

Page 5: Adolescents' exposure to community violence: Sleep and psychophysiological functioning

as a 3 level (low, moderate, high) categorical variable, using t-tests and x2, respectively.Youth whose CREV score fell into the lowest quartile were assigned to the “low” catego-ry; those in the middle 2 quartiles to the “moderate;” and those in the upper quartile tothe “high.” T-tests revealed no significant gender or age differences in sleep disturbance.

There were significant gender differences (Baseline systolic: t(23) 5 2.12; p , .05)as well as statistical trends (Baseline pulse rate: t(25) 5 21.76; Interview systolic: t(25)5 1.77; p , .10) for the physiological variables. Given the recognized sex differences inblood pressure and pulse rates (cf., Brunswick & Collette, 1977), subsequent analyses in-volving autonomic variables controlled for sex. Age did not relate significantly to bloodpressure or pulse rate (p . .10).

Descriptive Data and Intercorrelations

For each variable of interest, mean scores, standard deviations, and ranges are reportedin Table 1. Youth used the full range of scores in reporting community violence; the high-est CREV score was 99 out of a potential maximum of 116. Overall, youth reported ahigh amount of exposure to community violence. The average Sleep Patterns score sug-gests that most youth experienced at least occasional sleep disturbance. Mean bloodpressures were in the normotensive range (i.e., under the 90th percentile for their sexand mean age) as established by the National Heart, Lung, and Blood Institute’s Task

Psychophysiology, Sleep, and Community Violence • 371

Table 2. Comparison of Level of Exposure to Community Violence With Sleep Disturbance and Psychophysiological Arousal

Low Exposure Moderate Exposure High ExposureVariable N M (SD) M (SD) M (SD) F df p

ANOVASleep disturbance 62 5.12 (2.18) 6.35 (2.58) 7.94 (4.06) 3.81 2 .03

MANCOVABaseline—systolic 25 119.50 (9.79) 118.03 (12.23) 97.50 (43.77)Sex 4.93 1 .04Community violence 3.29 2 .06Baseline—Diastolic 25 66.60 (9.36) 68.47 (8.37) 69.75 (22.29)Sex 0.04 1 .85Community violence 0.07 2 .93Baseline—pulse rate 25 77.90 (5.75) 79.91 (13.59) 60.56 (18.01)Sex 0.39 1 .54Community violence 2.88 2 .08

MANCOVAInterview—systolic 25 121.88 (9.28) 121.64 (11.22) 111.60 (22.32)Sex 3.58 1 .07Community violence 1.76 2 .20Interview—Diastolic 25 77.82 (6.46) 80.98 (16.15) 73.38 (15.92)Sex 1.96 1 .18Community violence 0.72 2 .50Interview—pulse rate 25 81.44 (13.03) 79.19 (10.16) 69.68 (4.61)Sex 0.01 1 .94Community violence 1.56 2 .23

Page 6: Adolescents' exposure to community violence: Sleep and psychophysiological functioning

Force on High Blood Pressure in Children and Adolescents (1996). The zero-order cor-relations in Table 1 provide data on multi-collinearity.

General Linear Models

Univariate Analyses. Analysis of variance (ANOVA) compared level of community violenceexposure (low, moderate, high) with sleep disturbance. The F-value was significant (seeTable 2). Compared with those with the least exposure, post-hoc analyses (Scheffe; p ,.05) revealed that youth with the highest level of community violence reported the mostdifficulty sleeping.

Multivariate Analyses. Because the psychophysiological variables were interrelated and toreduce the effects of multicollinearity (see Table 1), multivariate analyses of covariance(MANCOVAs) were conducted. Physiology data from the baseline and interview assess-ment periods were analyzed in separate MANCOVAs, which controlled for sex. MAN-COVA was used to compare the differential relationship of level of community violenceexposure to physiological arousal. Univariate analyses were conducted to examine be-tween group differences.

At baseline, statistical trends (p , .10) suggested differences in systolic blood pres-sure and pulse rates for youth exposed to pervasive community violence. Univariate (AN-COVA) analyses indicated that youth with the highest level of exposure to community violence had the lowest resting heart (Systolic: F(1,20) 5 4.96; p , .05) and pulse(F(1,20) 5 4.73; p , .05) rates compared with the youth with lesser community violenceexposure. Level of community violence did not affect interview blood pressure or pulserates.

DISCUSSION

Studies of significant life events reveal that such events negatively impact youths’ affec-tive, behavioral, cognitive, and physiological-somatic functioning. Identified physiologi-cal and biological responses can include sleep disturbance (Armsworth & Holaday,1993). Quality and quantity of sleep are important to assess because adolescents withsleep problems are more anxious, depressive, inattentive, and conduct disordered thanadequate sleepers (Morrison et al., 1992). Duncan’s (1996) review documented that ur-ban children exposed to neighborhood violence exhibited sleep disturbance. Consistentwith the current study’s results, exposure to community violence was positively associat-ed with sleep disturbance. Relatedly, Dollinger, Molina, and Monteiro (1996) investigat-ed the relationship between sleep and children’s contextually-based fears. Among low-income urban Brazilian children, environmental and culturally based worries related tosleep disturbance. This study’s respondents reported, on average, only occasional sleepdifficulties. If such problems persist and lead to chronic sleep deprivation, major nega-tive consequences may result including increased vulnerability to daytime sleepiness, ac-cidents, mood and behavior problems, and drug and alcohol use (Carskadon, 1990).Even occasional poor sleepers lack energy, are tense, moody, irritable, depressed, andfeel less rested than youth who sleep well (Kirmil-Gray, Eagleston, Gibson, & Thoresen,1984). Clearly, these symptoms may affect youth’s ability to function maximally in social,academic and work settings.

Adolescents living in inner-cities have higher blood pressures than youth living insuburban or rural areas (Thomas & Groer, 1986), independent of race (Burns, Morri-

372 • Journal of Community Psychology, July 1999

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son, Khoury, & Glueck, 1980). Urban living is described as less esthetically pleasing, nois-ier, and more crowded (Thomas & Groer, 1986). Surprisingly, this study found that ur-ban adolescents with the highest levels of exposure to community violence had the low-est resting blood pressure. This pattern is consistent with the suggestion that, for someyouth, exposure to community violence involves a “desensitization process” (Fitzpatrick& Boldizar, 1993). Youth so affected display uncaring and emotionally neutral responsesto witnessed violence. It is assumed that desensitization results from having to adjust tofrequent pain and loss (Osofsky, Werers, Hann, & Fick, 1993) and from perceiving vio-lent events as normal and “nothing special” (Lorion & Saltzman, 1993). Our findings sug-gest that the observed emotional desensitization may accompany or result from physio-logical habituation. Singly or in combination, these responses may represent a means ofadapting to chaotic communities. This adaptation may be protective in the sense thatsigns of danger (e.g., people yelling, police and ambulance sirens, gun shots) occur withsuch frequency that youth learn not to react with a “fight or flight” response but insteadhabituate to fear (e.g., Mowrer, 1960). Extended contact with fear-producing stimuli mayresult in increased physiological reactivity and subjective distress (Turner, Beidel, & Coo-ley-Quille, 1997). With repeated exposure over time, stimuli that originally elicited phys-iological reactivity (e.g., sirens, gun shots) may occur with such frequency that youth be-come desensitized. This may serve a protective—albeit disturbing—function for youthat the extreme level of exposure such that it allows them to function “normally” in con-texts overun by violence.

Although there were significant differences in resting (“baseline”) physiologicalarousal between youth exposed to low, moderate, and high levels of community violence,no significant differences were found for those youth during the interview. Since the in-terview is a non-threatening experience, differences would not be expected. Ideally, anappropriate behavioral assessment task may require some form of exposure to commu-nity violence (e.g., youth could observe films that depict people committing violent actsin communities) while their autonomic responses were assessed. Alternatively, ambula-tory monitors could be used to measure youth’s physiology over 24-hour periods undernatural circumstances. Our non-significant findings may reflect the study sample’s sizeand convenience. It must also be acknowledged that the pilot study relied on a singledata source (i.e., the youth themselves), although different levels of analysis were used(e.g., self-report, psychophysiological assessment).

Without question, future studies must be conducted on this issue. Ideally, such stud-ies would measure sleep disturbance using both advanced technologies (e.g., sleep lab-oratories, measure EEG) and confirm findings under natural circumstances (e.g., dailysleep/wake logs or diaries). It would also seem important to combine these “hard” meth-ods with information obtained using ethnographic and observational techniques. Un-derstanding the qualitative experience of living under such conditions seems essential tous if the physiological findings are to be interpreted in ecologically valid ways.

Until we complete the picture, however, some steps can be taken now. To help ur-ban youth who are frequently exposed to violence in their communities cope with stress,parental support and open communication are beneficial, informal strategies to en-courage in families (Duncan, 1996). It is important for interventionists to assist youth inadapting to the chaotic environments in which they live, recognizing that frequent ex-posure to violent events may lead some youth to interpret these events as “normative.”Failing to experience physiological reactivity (due to desensitization) despite signs of en-vironmental danger (e.g., police and ambulance sirens, helicopters, gun shots) may re-inforce this belief. It may be beneficial to help youth recognize healthy ranges of emo-

Psychophysiology, Sleep, and Community Violence • 373

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tional and physiological responses (i.e., neither extreme) and understand that becom-ing seemingly “unaffected” by signs of danger may be protective or functional in theshort-term, but detrimental in the long-term.

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