Johnna Medina, PhD, is a Clinical Instructor at Stanford medicine in the Department of Psychiatry and Behavioral Sciences, where she is an attending psychologist in the Addiction Medicine/Dual-Diagnosis Clinic and continues to collaborate on research projects evaluating mind-body interrelationships (e.g., stress and health) and interventions (e.g., hypnosis, yoga). Dr. Medina earned her bachelor's degrees in Psychology and Art Practice at Stanford University (2009) and her PhD in Clinical Psychology at UT Austin (2017). Her dissertation research focused on exercise and yoga-based interventions for targeting anxiety-related risk and maintenance factors underlying addictive behaviors. She returned to Stanford to complete her postdoctoral research fellowship (2017-2019) as a T32 scholar working under Dr. David Spiegel in the Center on Stress and Health Lab.
Academic Staff - Hourly, Psychiatry and Behavioral Sciences
Fellowship: Stanford University Psychology Postdoctoral Fellowship (2019) CA
Internship: Bruce W Carter VA Medical Center (2017) FL
PhD Training: University of Texas at Austin Registrar (2017) TX
DO RESEARCH PARTICIPANTS DIFFER BY RECRUITMENT SOURCE?OBSERVATIONS FROM A STUDY OF NEWLY-DIAGNOSED BREAST CANCER PATIENTS
OXFORD UNIV PRESS INC. 2020: S75
View details for Web of Science ID 000546262400156
Evening salivary cortisol as a single stress marker in women with metastatic breast cancer.
2020; 115: 104648
Flattened diurnal salivary cortisol patterns predict shorter subsequent survival with breast, lung, and renal cell carcinomas. The underlying cause of this flattened slope is undetermined, though it has been hypothesized to be secondary to a deficit in the amplitude of the circadian clock. To gain greater insight into the portions of the diurnal salivary curve that are associated with cancer survival, we examined (1) which points in the diurnal curve are predictive of the slope of the curve and (2) whether elevated evening cortisol levels alone are associated with reduced HPA-axis feedback inhibition (i.e., decreased sensitivity to the dexamethasone suppression test).We examined study hypotheses on adult women with advanced breast cancer (age = 54.3 ± 9.58 years; n = 99) using non-parametric Wilcoxon's rank-sum tests, Spearman correlation coefficients and an accuracy formula based on a confusion matrix. Cortisol was sampled five times per day for three consecutive days, with dexamethasone administered late on the second day.Salivary cortisol concentrations did not vary between those with flat and steep slopes during the morning (p's > .05), but did vary in the evening (p's < 0.05). Furthermore, the concentration of the 2100h alone was 86% accurate in discriminating between individuals classified as having "flat" or "steep" slopes. Dexamethasone suppression was only associated with diurnal salivary cortisol slope (p = .0042).Evening cortisol levels are a sensitive indicator flattened diurnal cortisol slope, suggesting evening cortisol may also be a useful predictor of breast cancer survival. Future research should focus on determining the causes of abnormally increased evening cortisol.
View details for DOI 10.1016/j.psyneuen.2020.104648
View details for PubMedID 32171899
Examining experiential avoidance as a mediator of the relation between anxiety sensitivity and depressive symptoms.
Cognitive behaviour therapy
Initial evidence suggests that experiential avoidance (EA) mediates the relation between anxiety sensitivity (AS) and depression. We examined the AS-EA-depression pathway, examining both concurrent, and prospective (cross-lag), mediation models. Utilizing data from a study that examined the effects of exercise on AS (N =60), we modeled depressive symptoms, EA, and AS over four time points. Time-varying predictors were disaggregated into between-subjects (each person's mean level of the predictor) and within-subjects change (each person's deviations, at each time point, from their mean level on the predictor) components. Tests of the concurrent relations were partially consistent with predictions, with mean EA levels, but not within-subjects changes in EA, partially mediating the relation between AS and depression symptom severity. However, the prospective, cross-lag mediation model, in which AS predicted future EA controlling for previous EA, and EA predicted future depression, controlling for previous depression, yielded no significant effects. These results suggest that observed between-subjects mediation findings, found here and in previous studies, may not replicate using more stringent, quasi-causal, cross-lag mediation analyses. These results highlight the importance of estimating causal pathways in mediation analyses. Clinical implications and directions for future research are discussed.
View details for PubMedID 30507350