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This article was submitted to Psychology for Clinical Settings, a section of the journal Frontiers in Psychology.
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Accumulating evidence indicates that psychotherapy participants show increased physiological responsiveness to stress. The purpose of the present study was to examine differences between individuals participating in outpatient psychotherapy and matched controls using an experimental design. Forty-two psychotherapy participants and 48 matched controls were assessed on cardiovascular and cortisol functioning at baseline, during the Trier Social Stress Test (TSST), and during a 20-min recovery period. Psychotherapy participants and matched controls did not differ at baseline or during the TSST on the physiological measures but psychotherapy participants had higher cortisol and heart rate (HR) during the recovery period. In regards to reactivity, cortisol increased during the recovery period for the psychotherapy participants but decreased for those in the matched control group. Psychotherapy participants experiencing clinically significant levels of distress displayed elevated systolic and diastolic blood pressure and HR during the TSST when compared to psychotherapy participants not experiencing clinically significant levels of distress. Overall, physiological reactivity to stress appears to be an important issue for those in psychotherapy and directly addressing this issue may help improve psychotherapy outcomes.
High levels of psychological distress contribute to elevated physiological activity and negative health outcomes (
Stress is a highly prevalent problem with significant negative consequences (
Stress reactivity, or the way individuals physiologically and emotionally respond to stressful situations, is central in understanding how we are affected by stress and how it impacts our functioning. Physiological measurements, such as cardiovascular indices and hormonal change, are an integral aspect of evaluating individual’s stress reactivity. Increased levels of cortisol have consistently been linked to experienced acute and/or chronic stress (
Individuals engaged in psychotherapy display exaggerated physiological reactivity to stress.
In a more general study about adolescents’ externalized behavioral problems,
To determine if stress reduction techniques enhance therapy outcome,
The purpose of the present study was to examine whether psychotherapy participants in an outpatient setting would show elevated physiology relative to a matched control group. Three hypotheses were tested. First, psychotherapy participants would show elevated physiology at baseline before beginning the laboratory stressor. Second, psychotherapy participants would show a larger overall response to the laboratory stressor than the control group. And third, the psychotherapy participants would show increased physiological reactivity to the stressor with greater changes from baseline to stressor.
Forty-two psychotherapy patients were recruited from the Brigham Young University, Provo Utah, counseling center. Psychotherapy patients entering the study had just begun psychotherapy and had received one to two sessions only. A matched control group of 48 college students not receiving psychotherapy were recruited via a research participation system run by the psychology department. Our sample was comprised of college students only. About 57% of participants were females, and 43% were males. The average age of all participants was approximately 23 (SD = 4.1) and the mean BMI was 23.4 (SD = 3.4). This study received Institutional Review Board approval before beginning and all participants read and signed an informed consent form before participating in the study.
The study proceeded in two phases: (a) completion of preliminary questionnaires, and (b) laboratory physiological stress reactivity measurement. All procedures were approved by the Brigham Young University Institutional Review Board. Preliminary questionnaires involved informed consent, a self-report measures of psychological distress, and demographic information. The second phase of the study involved the laboratory stress task. During the laboratory tasks, participants’ physiological measures of stress reactivity were collected. Participants’ completion of the study was compensated with 20 dollars cash.
Physiological stress reactivity was assessed through induction of a stressful situation using the TSST (
Client reported their age and gender, and then were weighed and measured in order to calculate body mass index (BMI).
Psychotherapy outcome and participant’s progress was monitored using the Outcome-Questionnaire (OQ-45,
Heart rate, diastolic, and systolic blood pressure (SBP) data were collected using a Dinamap Model 8100 automated blood pressure monitor (Critikon Corporation, Tampa, FL, USA) that capitalizes on the oscillometric method. Readings were obtained following the specifications of the manufacturer using a cuff that was measured and properly sized to fit on the upper non-dominant arm of the participant. Cortisol was measured via saliva samples. Salivary samples were stored at -20°C until analysis. After thawing the samples, the salivettes were centrifuged for 5 min at 3000 rpm. Concentrations of salivary cortisol were measured using a commercially available immunoassay with chemiluminescence detection (CLIA; IBL, Hamburg, Germany).
Before analyzing the research questions, experimental groups were first compared to examine whether groups were not significantly different at baseline for demographic, blood pressure, and psychological distress using independent sample
Sample characteristics by experimental group.
Psychotherapy group ( |
Control group ( |
||
---|---|---|---|
Gender (% female) | 57% | 56% | 0.93 |
Age | 22.9 (4.1) | 23.0 (4.4) | 0.88 |
Body mass index | 23.4 (3.4) | 24.3 (5.2) | 0.32 |
Outcome questionnaire | 73.6 (25.7) | 43.1 (16.5) | <0.001 |
Systolic blood pressure (mm/Hg) | 108 (10) | 109 (11) | 0.49 |
Diastolic blood pressure (mm/Hg) | 65 (7) | 64 (7) | 0.71 |
Heart rate (bpm) | 69 (11) | 73 (11) | 0.10 |
Cortisol (nmol/l) | 11.8 (7.4) | 11.4 (7.1) | 0.80 |
Systolic blood pressure (mm/Hg) | 112 (13) | 112 (12) | 0.85 |
Diastolic blood pressure (mm/Hg) | 67 (7) | 65 (7) | 0.37 |
Heart rate (bpm) | 74 (11) | 70 (11) | 0.03 |
Cortisol (nmol/l) | 12.7 (10.9) | 9.5 (4.9) | 0.01 |
The psychotherapy group and matched control group did not differ at baseline on measures of SBP, diastolic blood pressure (DBP), HR, or cortisol. In other words, participants in psychotherapy were not more physiologically aroused than matched controls at the beginning of the experiment. Similarly, there were no differences in average physiological stress responses between groups. During the beginning of the recovery phase, those in the psychotherapy group had elevated cortisol [
Sample characteristics by level of clinical distress for those in the psychotherapy group only.
High distress ( |
Low distress ( |
||
---|---|---|---|
Gender (% female) | 58% | 56% | 0.90 |
Age | 23.2 (4.5) | 22.8 (4.1) | 0.60 |
Body mass index | 23.1 (3.7) | 24.3 (4.8) | 0.20 |
Systolic blood pressure (mm/Hg) | 117 (10) | 110 (11) | 0.03 |
Diastolic blood pressure (mm/Hg) | 66 (7) | 62 (7) | 0.02 |
Heart rate (bpm) | 76 (12) | 69 (10) | 0.03 |
Systolic blood pressure (mm/Hg) | 109 (10) | 108 (11) | 0.94 |
Diastolic blood pressure (mm/Hg) | 66 (7) | 64 (7) | 0.19 |
Heart rate (bpm) | 72 (12) | 70 (10) | 0.40 |
Systolic blood pressure (mm/Hg) | 126 (16) | 123 (15) | 0.082 |
Diastolic blood pressure (mm/Hg) | 77 (9) | 73 (8) | 0.395 |
Heart rate (bpm) | 81 (15) | 80 (12) | 0.757 |
Because cortisol was not different between groups at baseline but did differ during recovery, there was a significant difference in terms of physiological reactivity following the stressor. The overall within subjects analysis was
The purpose of this study was to examine whether physiological response to a laboratory stressor would be higher in psychotherapy participants relative to a matched control group. It was hypothesized that psychotherapy participants would have elevated baseline physiology, elevated average physiological response, and greater reactivity to a speech and math stressor relative to baseline levels. No group differences in physiology were found at baseline. Those in psychotherapy did report higher levels of psychological distress as might be expected. There were no differences between groups in average physiological response; however there was a significant difference when comparing those with high levels of clinical distress with those with low levels. Those high in clinical distress displayed higher overall SBP, DBP, and HR to the TSST than did the low distress group. In regards to physiological reactivity, the psychotherapy group showed greater cortisol levels following the TSST relative to the control group indicating a stronger stress response.
There are three key implications of these findings. First, not everyone engaged in psychotherapy has clinical levels of distress and it appears that overall level of clinical distress is an important factor in physiological response to stress. However, most of those who qualified as clinically distressed were in the psychotherapy group. Given the limited size of this study and the small number of controls with clinical distress, there was insufficient power to see whether there was an interaction between psychotherapy participation and clinical distress.
The second implication is that psychotherapy participants may look normal physiologically at rest but have an exaggerated response to stressful situations. To examine the impact of stress in psychotherapy, it is insufficient to measure just baseline physiology. Rather, it is the reaction to and recovery from stressful situations that are important (
The third implication is that stress reduction strategies may be a useful adjunct for those in psychotherapy. High levels of stress can interfere with attention and focus and stress reduction may help improve psychotherapeutic efforts by reducing physiological stress symptoms.
There are several limitations to this study. First, this study was cross sectional in nature so it is not clear how stress physiology impacts long term outcome in psychotherapy. Second, the sample consisted of relatively young, healthy college students with psychotherapy being administered in a counseling center. It is not known if these results will generalize to other age groups, conditions, or different clinical settings. Strengths of the current study were the inclusion of a matched control group with no previous psychotherapy experience and a controlled experimental design. Future studies could build on these findings by conducting controlled experimental longitudinal studies to examine how reducing stress physiology is related to psychotherapy outcome and by looking at different age groups and different clinical settings. Additionally, focusing on the role of resilience in the relationship between psychotherapy and psychophysiological stress reactivity may be especially fruitful (see
In conclusion, people with who are clinically distressed display greater physiological response and greater physiological reactivity to a laboratory stressor relative to a matched control group. Distressed individuals did not differ at baseline physiologically indicating resting physiological measures may be insufficient to identify those who may be at risk of stress related problems in psychotherapy. Rather, examining stress response as well as ability to recover from stress once the stressor is over is crucial. Stress reduction techniques may be a beneficial adjunct to psychotherapy and future studies could examine this possibility using a longitudinal controlled experiment.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.