stress and (un)healthy aging - pennsylvania state university
TRANSCRIPT
Stress and (un)Healthy Aging
Martin Sliwinski
Penn State University
What is aging?
Aging: the accumulation of changes in an organism over time
Risk Mechanisms & Regulators (behavioral, biological & social)
Time-scales (linking short-term & long-term changes)
Aging often involves the study of involution (vs. growth/development)
Stress and (un)Healthy Aging
Memory Executive function
Cognitive Health Physical Health Emotional Health
Metabolic disorder Cardiovascular disease
Depression Anxiety
“Stress”
The Important Question(s)…
What connects stress exposure to health outcomes?
Health Emotional
Cognitive
Physical
Exposure
Event/
Hazard ?
What are critical periods in adulthood for intervention (normative/age-graded vs. nonnormative)
What is stress?
Physiological/Behavioral
Responses
Negative Emotional Response
Stress Response
(psychophysiological
sequelae)
What is stress?
Benign
Appraisal
Perceived
Stress “Subjective Stress” (experiential state)
Appraisal of Demand & Capacity
Environmental Challenge Stressor/Hazard (exposure)
Cohen, S., Kessler, R. C., & Underwood Gordon, L. (Eds.) (1995). Measuring
stress: A guide for health and social scientists. New York: Oxford.
What Makes Stress Bad?
Stress is not the culprit, chronic stress is!
Chronic Stress Persistent experience of negative emotional states
Allostatic Load: “Wear and Tear”
“wear and tear that results
from the physiological response to
stress” Allostatic Load
McEwen, B. S. (1998) Protective and Damaging Effects of Stress Mediators. New England J.Med. 338: 171-179
The process of stress pathogenesis (‘critical periods’)
Time
Health Emotional
Cognitive
Physical
Dispositional
Shifts
Behavioral
Affective
Physiological
Physiological
Dysregulation
HPA activity
Cardiovascular
Inflammation
Enduring
Emotional
States
Immediate
Stress
Response
Exposure
Event/
Hazard
Moments/ Minutes
Hours/ Days
Days/ Months
Months/ Years
Years/ Decades
Maladaptive (chronic stress)
Adaptive (acute stress)
Dysregulation/ Impairment
Mechanisms & Risk Regulators (critical period)
Distinguish immediate from enduring stress responses
What should we measure?
“Today/last few hours” …Argument (or avoided argument) …Overload at work or home …Traffic/weather
Everyday stress (daily hassles)
“Any idiot can handle a crisis—it’s this day-to-day living that wears you out.” —Anton Chekhov
“straw that broke the camel’s back”
“Trait” Reactivity
Reactivity is “a stable individual difference in response to stressors” (Cohen et al., 2000)
Daily Stress research has mostly focused on (stable) individual differences (high vs. low responders)
Few studies have examined time-varying (contextual) effects on daily stress
Daily Stress Response is operationalized by the slope relating level of stress on a given day to a person’s negative affect (NA) [or cortisol output]
6 daily
measurements
Burst 1 Burst 4 Burst 3 Burst 2 6 mos. 6 mos. 6 mos. 6 mos.
Burst 5
Measurement-Burst Design
6 daily
measurements 6 daily
measurements
6 daily
measurements
6 daily
measurements
Sample Cognitively intact, non-depressed, independent living adults (N=104) ages 65-95
Measures Daily negative affect (NA), daily stress (hassles), Background stress (30 days prior to each
burst)
(Nesselroade, 1991)
‘Reactivity’ varies more within than between persons
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Person Level Burst Level
% o
f to
tal
Var(
Reacti
vit
y)
Source Var(Reactivity) SE p-value
Between-Person 0.026 0.014 0.02
Within-Person 0.080 0.020 <.01
~24% of the variance in emotional responses is ‘stable’
Burst 1
severity
NA
Burst 2
severity
NA
Burst 3 Burst 4
severity
NA
severity
NA
severity
NA
severity
NA
P1
P2
Burst 5
severity
NA
severity
NA
severity
NA
severity
NA
Within-person variability in background stress (during 30 days prior to burst) predicted within-person variability in slopes
Low stress burst High stress burst
High stress burst Low stress burst
“Daily” Emotional Responses are a mixed bag
Most diary studies use 24 hour recall
Impossible to sequence stressor/event and emotions
The daily stress ‘response’ conflates immediate reactions and enduring mood states (prolonged effects)
Pathogenic Convey Risk (individual differences)
Experience Sampling Design
Query individuals about their mood, thoughts and experiences at pseudo-random times throughout the day
Completed surveys on palmtop computer… 1. Upon waking (WAKE)
2. At 5 random times throughout the day (BEEP) 3. Prior to going to bed (EOD)
…for 7 consecutive days
Lagged effects Enduring responses (3-6 hours)
Concurrent effects “Immediate” responses (0-3 hours)
Stressful Events Negative Affect
Fixed Effects
Time Variable Effect
Stressful events predict current and subsequent NA…
Current Event (t) (0-3 hours) b=4.57, p<.01
Prior Event (t-1) (3-6 hours) b=1.44, p<.01
Variances
Current Event (t) (0-3 hours)
Prior Event (t-1) (3-6 hours)
% Between-Person
13%
43%
Prolonged (lagged) responses exhibit relatively more stable (dispositional) variance
Differential Moderation of Current and Lagged Effects
Recent Social Exchanges Prior evening’s sleep Anticipated Stress
Contextual (state) Variables
Current Event Effects (Immediate)
Lagged Event Effects (enduring)
Personality (PA) Education Cognitive (fluid) function
Dispositional (‘stable’) Variables
What connects everyday stress to long-term health outcomes?
Time
Discrete
Events
Acute
Response
Health
Mental
Cognitive
Physical
Prolonged
Activation
(emotional/
physiological)
Chronic Exposure
Ongoing events and strains
Physiological
Dysregulation
HPA activity
Cardiovascular
Inflammation
An important mechanismChronic Stress
Perseverative Cognition (PC) “Repetitive thinking about problematic situations or events” (worry, rumination)
“I have thoughts I cannot stop”
“My thoughts frequently return to one idea”
“I tend to replay past events as I would have liked them to happen”
“When I have an important event coming up, I can’t stop thinking about it”
-- Endocrine response (Zoccola et al., 2008)
--Cardiac effects (Pieper et al., 2007)
-- Negative affect (NA) (Moberly et al., 2008)
--Cognition (Stawski et al., 2006)
Heuristic Model of Chronic Stress
Time
Discrete
Events
Acute
Response
Health
Mental
Cognitive
Physical
Prolonged
Activation
(emotional/
physiological)
Chronic Exposure
Ongoing events and strains
Physiological
Dysregulation
HPA activity
Cardiovascular
Inflammation
Months/years
Hours/days
Perseverative
Cognition
Perseverative Cognition & Severity Negative Affect
Within-Day
Prior Event (t-1)
Current Event (t)
(3-6 hours)
(0-3 hours)
Time Variable Effect
Severity
Thoughts
b= 0.21, p=.13
b=0.78, p<.01
Severity
Thoughts
b=0.03, ns
b=0.16, p=.01
How much you think about a stressor now predicts how you will feel later in the day
Severity & PC Negative Affect
Across-day
Prior Day Event (t-1) (24-48 hours)
Time Variable Effect
Severity
Thoughts
b=-0.36, ns
b=1.00, p<.01
How much you think about a stressor now also predicts how you feel at the end of the day tomorrow
Next steps…
1. Linking psychological/behavioral and biological mechanisms
2. Neural basis for PC
How do stressors ‘get under the skin’? (telomere, inflammation)
3. Why do people worry/ruminate?
What reinforces worry?
Engage/disengage attention Attentional bias
25
Colleagues
Robert Stawski
Jacquie Mogle
Liz Munoz
Stacey Scott
Dave Almeida
Bill Gerin
Nilam Ram
Joshua Smyth
Scott Hofer
Investigators/Fellows/Students
NIH AG-26728 ,12448, and AG26453
Daily Stress and Health Risk
Physical Health: Daily stress is associated with… greater risk of disease burden (10 year follow-up) greater risk of all-cause mortality (5-10 year follow-up) (Almeida and colleagues, in review)
Mental Health: Daily stress increases long-term risk depression (daily stress a stronger predictor than spousal/childhood abuse)
Cognitive Health: Responses to daily stress associated with lower executive function (Stawski et al. 2010) and working memory (Sliwinski et al., 2006)
Perseverative Cognition (PC) accounts for stress effects
Stress
Exposure
Metabolic Risk 27%*
Cortisol waking
rise
40%*
Sleep quality 45%**
Working memory 57%**
Percent of exposure effects on health outcomes accounted for by Perseverative Cognition tendencies
PC N=383 *p<.05; **p<.01