- Dialectical Behavior Therapy
- Acceptance and Commitment Therapy
- Emotion Regulation
- Personality Development
Director, Stanford DBT, Stanford University Medical Center (2011 - Present)
Clinical Director, Early Life Stress and Pediatric Anxiety Program, Stanford Children's (2012 - 2015)
Assistant Clinical Director, Child Psychiatry Outpatient Services, Stanford Children's (2013 - Present)
Fellowship: Stanford University Psychology Postdoctoral Fellowship (2010) CA
PhD Training: Penn State College of Medicine (2008) PA
Internship: Beth Israel Medical Center - New York (2008) NY
Current Research and Scholarly Interests
Dr. Zack is involved with ongoing research related to the treatment of adolescent and adult trauma (Trauma Focused Cognitive Behavioral Therapy - TF-CBT; Prolonged Exposure - PE), and the effective provision of Dialectical Behavior Therapy (DBT) to adolescent girls and women with disorder of emotion regulation. She additionally studies Acceptance and Commitment Therapy (ACT) for adolescent girls with anxiety. More broadly she is interested in the impact of Evidenced Based Treatments on improving quality of life, and helping individuals find the right match for clinical care. Research is conducted through the Early Life Stress and Pediatric Anxiety Disorders Program at Stanford Children's Hospital and the Stanford Dialectical Behavior Therapy Program.
Changes in Brain Volume Associated with Trauma-Focused Cognitive Behavioral Therapy Among Youth with Posttraumatic Stress Disorder.
Journal of traumatic stress
This study investigated group differences and longitudinal changes in brain volume before and after trauma-focused cognitive behavioral therapy (TF-CBT) in 20 unmedicated youth with maltreatment-related posttraumatic stress disorder (PTSD) and 20 non-trauma-exposed healthy control (HC) participants. We collected MRI scans of brain anatomy before and after 5 months of TF-CBT or the same time interval for the HC group. FreeSurfer software was used to segment brain images into 95 cortical and subcortical volumes, which were submitted to optimal scaling regression with lasso variable selection. The resulting model of group differences at baseline included larger right medial orbital frontal and left posterior cingulate corticies and smaller right midcingulate and right precuneus corticies in the PTSD relative to the HC group, R2 = .67. The model of group differences in pre- to posttreatment change included greater longitudinal changes in right rostral middle frontal, left pars triangularis, right entorhinal, and left cuneus corticies in the PTSD relative to the HC group, R2 = .69. Within the PTSD group, pre- to posttreatment symptom improvement was modeled by longitudinal decreases in the left posterior cingulate cortex, R2 = .45, and predicted by baseline measures of a smaller right isthmus (retrosplenial) cingulate and larger left caudate, R2 = .77. In sum, treatment was associated with longitudinal changes in brain regions that support executive functioning but not those that discriminated PTSD from HC participants at baseline. Additionally, results confirm a role for the posterior/retrosplenial cingulate as a correlate of PTSD symptom improvement and predictor of treatment outcome.
View details for DOI 10.1002/jts.22678
View details for PubMedID 33881197
Amygdala and Insula Connectivity Changes Following Psychotherapy for Posttraumatic Stress Disorder: A Randomized Clinical Trial.
BACKGROUND: Exposure-based psychotherapy is a first-line treatment for posttraumatic stress disorder (PTSD), but its mechanisms are poorly understood. Functional brain connectivity is a promising metric for identifying treatment mechanisms and biosignatures of therapeutic response. To this end, we assessed amygdala and insula treatment-related connectivity changes and their relationship to PTSD symptom improvements.METHODS: Individuals with a primary PTSD diagnosis (N= 66) participated in a randomized clinical trial of prolonged exposure therapy (n= 36) versus treatment waiting list (n= 30). Task-free functional magnetic resonance imaging was completed prior to randomization and 1 month following cessation of treatment/waiting list. Whole-brain blood oxygenation level-dependent responses were acquired. Intrinsic connectivity was assessed by subregion in the amygdala and insula, limbic structures key to the disorder pathophysiology. Dynamic causal modeling assessed evidence for effective connectivity changes in select nodes informed by intrinsic connectivity findings.RESULTS: The amygdala and insula displayed widespread patterns of primarily subregion-uniform intrinsic connectivity change, including increased connectivity between the amygdala and insula; increased connectivity of both regions with the ventral prefrontal cortex and frontopolar and sensory cortices; and decreased connectivity of both regions with the left frontoparietal nodes of the executive control network. Larger decreases in amygdala-frontal connectivity and insula-parietal connectivity were associated with larger PTSD symptom reductions. Dynamic causal modeling evidence suggested that treatment decreased left frontal inhibition of the left amygdala, and larger decreases were associated with larger symptom reductions.CONCLUSIONS: PTSD psychotherapy adaptively attenuates functional interactions between frontoparietal and limbic brain circuitry at rest, which may reflect a potential mechanism or biosignature of recovery.
View details for DOI 10.1016/j.biopsych.2020.11.021
View details for PubMedID 33516458
- Longitudinal changes in brain function associated with symptom improvement in youth with PTSD JOURNAL OF PSYCHIATRIC RESEARCH 2019; 114: 161–69
- Intrinsic Brain Connectivity Moderators of Psychotherapy Response and Changes in PTSD: A Combined Connectomic, Network Level, and Seeded Connectivity Approach ELSEVIER SCIENCE INC. 2019: S111–S112
Longitudinal changes in brain function associated with symptom improvement in youth with PTSD.
Journal of psychiatric research
2019; 114: 161–69
BACKGROUND: Previous studies indicate that youth with posttraumatic stress disorder (PTSD) have abnormal activation in brain regions important for emotion processing. It is unknown whether symptom improvement is accompanied by normative changes in these regions. This study identified neural changes associated with symptom improvement with the long-term goal of identifying malleable targets for interventions.METHODS: A total of 80 functional magnetic resonance imaging (fMRI) scans were collected, including 20 adolescents with PTSD (ages 9-17) and 20 age- and sex-matched healthy control subjects, each scanned before and after a 5-month period. Trauma-focused cognitive behavioral therapy was provided to the PTSD group to ensure improvement in symptoms. Whole brain voxel-wise activation and region of interest analyses of facial expression task data were conducted to identify abnormalities in the PTSD group versus HC at baseline (BL), and neural changes correlated with symptom improvement from BL to EOS of study (EOS).RESULTS: At BL, the PTSD group had abnormally elevated activation in the cingulate cortex, hippocampus, amygdala, and medial frontal cortex compared to HC. From BL to EOS, PTSD symptoms improved an average of 39%. Longitudinal improvement in symptoms of PTSD was associated with decreasing activation in posterior cingulate, mid-cingulate, and hippocampus, while improvement in dissociative symptoms was correlated with decreasing activation in the amygdala.CONCLUSIONS: Abnormalities in emotion-processing brain networks in youth with PTSD normalize when symptoms improve, demonstrating neural plasticity of these regions in young patients and the importance of early intervention.
View details for PubMedID 31082658
- Using fMRI connectivity to define a treatment-resistant form of post-traumatic stress disorder SCIENCE TRANSLATIONAL MEDICINE 2019; 11 (486)
Using fMRI connectivity to define a treatment-resistant form of post-traumatic stress disorder.
Science translational medicine
2019; 11 (486)
A mechanistic understanding of the pathology of psychiatric disorders has been hampered by extensive heterogeneity in biology, symptoms, and behavior within diagnostic categories that are defined subjectively. We investigated whether leveraging individual differences in information-processing impairments in patients with post-traumatic stress disorder (PTSD) could reveal phenotypes within the disorder. We found that a subgroup of patients with PTSD from two independent cohorts displayed both aberrant functional connectivity within the ventral attention network (VAN) as revealed by functional magnetic resonance imaging (fMRI) neuroimaging and impaired verbal memory on a word list learning task. This combined phenotype was not associated with differences in symptoms or comorbidities, but nonetheless could be used to predict a poor response to psychotherapy, the best-validated treatment for PTSD. Using concurrent focal noninvasive transcranial magnetic stimulation and electroencephalography, we then identified alterations in neural signal flow in the VAN that were evoked by direct stimulation of that network. These alterations were associated with individual differences in functional fMRI connectivity within the VAN. Our findings define specific neurobiological mechanisms in a subgroup of patients with PTSD that could contribute to the poor response to psychotherapy.
View details for PubMedID 30944165
Eye Movement Desensitization and Reprocessing and Dialectical Behavior Therapy
ASSESSING AND TREATING YOUTH EXPOSED TO TRAUMATIC STRESS
View details for Web of Science ID 000549804100013
- PTSD Psychotherapy Outcome Predicted by Brain Activation During Emotional Reactivity and Regulation AMERICAN JOURNAL OF PSYCHIATRY 2017; 174 (12): 1163–74
Selective Effects of Psychotherapy on Frontopolar Cortical Function in PTSD.
The American journal of psychiatry
2017; 174 (12): 1175-1184
Exposure therapy is an effective treatment for posttraumatic stress disorder (PTSD), but a comprehensive, emotion-focused perspective on how psychotherapy affects brain function is lacking. The authors assessed changes in brain function after prolonged exposure therapy across three emotional reactivity and regulation paradigms.Individuals with PTSD underwent functional MRI (fMRI) at rest and while completing three tasks assessing emotional reactivity and regulation. Individuals were then randomly assigned to immediate prolonged exposure treatment (N=36) or a waiting list condition (N=30) and underwent a second scan approximately 4 weeks after the last treatment session or a comparable waiting period, respectively.Treatment-specific changes were observed only during cognitive reappraisal of negative images. Psychotherapy increased lateral frontopolar cortex activity and connectivity with the ventromedial prefrontal cortex/ventral striatum. Greater increases in frontopolar activation were associated with improvement in hyperarousal symptoms and psychological well-being. The frontopolar cortex also displayed a greater variety of temporal resting-state signal pattern changes after treatment. Concurrent transcranial magnetic stimulation and fMRI in healthy participants demonstrated that the lateral frontopolar cortex exerts downstream influence on the ventromedial prefrontal cortex/ventral striatum.Changes in frontopolar function during deliberate regulation of negative affect is one key mechanism of adaptive psychotherapeutic change in PTSD. Given that frontopolar connectivity with ventromedial regions during emotion regulation is enhanced by psychotherapy and that the frontopolar cortex exerts downstream influence on ventromedial regions in healthy individuals, these findings inform a novel conceptualization of how psychotherapy works, and they identify a promising target for stimulation-based therapeutics.
View details for DOI 10.1176/appi.ajp.2017.16091073
View details for PubMedID 28715907
View details for PubMedCentralID PMC5711612
PTSD Psychotherapy Outcome Predicted by Brain Activation During Emotional Reactivity and Regulation.
The American journal of psychiatry
2017; 174 (12): 1163-1174
Exposure therapy is an effective treatment for posttraumatic stress disorder (PTSD), but many patients do not respond. Brain functions governing treatment outcome are not well characterized. The authors examined brain systems relevant to emotional reactivity and regulation, constructs that are thought to be central to PTSD and exposure therapy effects, to identify the functional traits of individuals most likely to benefit from treatment.Individuals with PTSD underwent functional MRI (fMRI) while completing three tasks assessing emotional reactivity and regulation. Participants were then randomly assigned to immediate prolonged exposure treatment (N=36) or a waiting list condition (N=30). A random subset of the prolonged exposure group (N=17) underwent single-pulse transcranial magnetic stimulation (TMS) concurrent with fMRI to examine whether predictive activation patterns reflect causal influence within circuits. Linear mixed-effects modeling in line with the intent-to-treat principle was used to examine how baseline brain function moderated the effect of treatment on PTSD symptoms.At baseline, individuals with larger treatment-related symptom reductions (compared with the waiting list condition) demonstrated 1) greater dorsal prefrontal activation and 2) less left amygdala activation, both during emotion reactivity; 3) better inhibition of the left amygdala induced by single TMS pulses to the right dorsolateral prefrontal cortex; and 4) greater ventromedial prefrontal/ventral striatal activation during emotional conflict regulation. Reappraisal-related activation was not a significant moderator of the treatment effect.Capacity to benefit from prolonged exposure in PTSD is gated by the degree to which prefrontal resources are spontaneously engaged when superficially processing threat and adaptively mitigating emotional interference, but not when deliberately reducing negative emotionality.
View details for DOI 10.1176/appi.ajp.2017.16091072
View details for PubMedID 28715908
View details for PubMedCentralID PMC5711543
- Selective Effects of Psychotherapy on Frontopolar Cortical Function in PTSD AMERICAN JOURNAL OF PSYCHIATRY 2017; 174 (12): 1175–84
Reorganization of Resting Connectivity Patterns Following Psychotherapy for Posttraumatic Stress Disorder
NATURE PUBLISHING GROUP. 2017: S122–S123
View details for Web of Science ID 000416846301019
- The Effects of Psychotherapy on Amygdalar Subregional Functional Connectivity in PTSD ELSEVIER SCIENCE INC. 2017: S236–S237
Brain Mechanisms and Predictors of Response to Prolonged Exposure Therapy in PTSD
NATURE PUBLISHING GROUP. 2016: S291–S292
View details for Web of Science ID 000440365600493
Attachment History as a Moderator of the Alliance Outcome Relationship in Adolescents
2015; 52 (2): 258-267
The role of the alliance in predicting treatment outcome is robust and long established. However, much less attention has been paid to mechanisms of change, including moderators, particularly for youth. This study examined the moderating role of pretreatment adolescent-caregiver attachment and its impact on the working alliance-treatment outcome relationship. One hundred adolescents and young adults with primary substance dependence disorders were treated at a residential facility, with a cognitive-behavioral emphasis. The working alliance and clinical symptoms were measured at regular intervals throughout treatment. A moderator hypothesis was tested using a path analytic approach. Findings suggested that attachment to the primary caregiver moderated the impact of the working alliance on treatment outcome, such that for youth with the poorest attachment history, working alliance had a stronger relationship with outcome. Conversely, for those with the strongest attachment histories, alliance was not a significant predictor of symptom reduction. This finding may help elucidate alliance-related mechanisms of change, lending support for theories of corrective emotional experience as one function of the working alliance in youth psychotherapy.
View details for DOI 10.1037/a0037727
View details for Web of Science ID 000354606900016
View details for PubMedID 25822108
- Mindfulness Based Interventions for Youth JOURNAL OF RATIONAL-EMOTIVE AND COGNITIVE-BEHAVIOR THERAPY 2014; 32 (1): 44-56
HELPFUL AND HINDERING EVENTS IN PSYCHOTHERAPY: A PRACTICE RESEARCH NETWORK STUDY
2010; 47 (3): 327-344
This paper presents the findings of a psychotherapy process study conducted within the Pennsylvania Psychological Association Practice Research Network (PPA-PRN). The investigation was the product of a long-term collaborative effort, both in terms of the study design and implementation, between experienced clinicians of various theoretical orientations and full-time psychotherapy researchers. Based on a relatively large sample of clients seen in independent practice settings, close to 1,500 therapeutic events (described by clients and therapists as being particularly helpful or hindering) were collected. These events were coded by three independent observers using a therapy content analysis system. Among the findings, both clients and therapists perceived the fostering of self-awareness as being particularly helpful. The results also point to the importance of paying careful attention to the therapeutic alliance and other significant interpersonal relationships. The merits and difficulties of conducting scientifically rigorous and clinically relevant studies in naturalistic contexts are also discussed.
View details for DOI 10.1037/a0021164
View details for Web of Science ID 000282850000007
View details for PubMedID 22402090