David Thiessen

Dr. David Thiessen

Mathematics and Statistics, University of Regina, Regina, Saskatchewan, Canada
orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 May 2021 in Journal of Medical Internet Research
Verified
Journal Article
Open access
HHHeather Hadjistavropoulos
Heather Hadjistavropoulos
HMHugh McCall
Hugh McCall
DTDavid Thiessen
David Thiessen
ZHZiyin Huang
Ziyin Huang
RCR. Nicholas Carleton
R. Nicholas Carleton
NTNick Titov
Nick Titov
Background: Canadian public safety personnel (PSP) experience high rates of mental health disorders and face many barriers to treatment. Internet-delivered cognitive behavioral therapy (ICBT) overcomes many such barriers, and is effective for treating depression, anxiety, and posttraumatic stress disorder (PTSD) symptoms. Objective: This study was designed to fill a gap in the literature regarding the use of ICBT tailored specifically for PSP. We examined the effectiveness of a tailored ICBT program for treating depression, anxiety, and PTSD symptoms among PSP in the province of Saskatchewan. Methods: We employed a longitudinal single-group open-trial design (N=83) with outcome measures administered at screening and at 8 weeks posttreatment. Data were collected between December 5, 2019 and September 11, 2020. Primary outcomes included changes in depression, anxiety, and PTSD symptoms. Secondary outcomes included changes in functional impairment; symptoms of panic, social anxiety, and anger; as well as treatment satisfaction, working alliance, and program usage patterns. Results: Clients reported large symptom reductions on measures of depression and anxiety, as well as moderate reductions on measures of PTSD and secondary symptoms, except for social anxiety. Most clients who reported symptoms above clinical cut-offs on measures of depression, anxiety, and PTSD during screening experienced clinically significant symptom reductions. Results suggested good engagement, treatment satisfaction, and working alliance. Conclusions: Tailored, transdiagnostic ICBT demonstrated promising outcomes as a treatment for depression, anxiety, and PTSD among Saskatchewan PSP and warrants further investigation. Trial Registration: Clinicaltrials.gov NCT04127032; https://www.clinicaltrials.gov/ct2/show/NCT04127032

7 September 2022 in Journal of Medical Internet Research
Verified
Journal Article
Open access
VPVanessa Peynenburg
Vanessa Peynenburg
HHHeather Hadjistavropoulos
Heather Hadjistavropoulos
DTDavid Thiessen
David Thiessen
NTNick Titov
Nick Titov
BDBlake Dear
Blake Dear
Background: Internet-delivered cognitive behavioral therapy (ICBT) can improve access to mental health care for students, although high attrition rates are concerning and little is known about long-term outcomes. Motivational interviewing (MI) exercises and booster lessons can improve engagement and outcomes in face-to-face cognitive behavioral therapy. Objective: This study aimed to examine the use of pretreatment MI exercises and booster lessons in ICBT for postsecondary students. Methods: In this factorial trial (factor 1: web-based MI before treatment; factor 2: self-guided booster lesson 1 month after treatment), 308 clients were randomized to 1 of 4 treatment conditions, with 277 (89.9%) clients starting treatment. All clients received a 5-week transdiagnostic ICBT course (the UniWellbeing course). Primary outcomes included changes in depression, anxiety, and perceived academic functioning from before treatment to after treatment and at the 1-month and 3-month follow-ups. Results: Overall, 54% (150/277) of students completed treatment and reported large improvements in symptoms of depression and anxiety and small improvements in academic functioning after treatment, which were maintained at the 1-month and 3-month follow-ups. Pretreatment MI did not contribute to better treatment completion or engagement, although small between-group effects favored MI for reductions in depression (Cohen d=0.23) and anxiety (Cohen d=0.25) after treatment. Only 30.9% (43/139) of students randomized to one of the booster conditions accessed the booster. Overall, no main effects were found for the booster. Subanalyses revealed that clients who accessed the booster had larger decreases in depressive symptoms (Cohen d=0.31) at the 3-month follow-up. No interactions were found between MI and the booster. Conclusions: Rather than offering MI before treatment, clients may experience more benefits from MI exercises later in ICBT when motivation wanes. The low uptake of the self-guided booster limited our conclusions regarding its effectiveness. Future research should examine offering a booster for a longer duration after treatment, with therapist support and a longer follow-up period. Trial Registration: ClinicalTrials.gov NCT04264585; https://clinicaltrials.gov/ct2/show/NCT04264585

6 February 2022 in Internet Interventions
Verified
Journal Article
Open access
HHHeather Hadjistavropoulos
Heather Hadjistavropoulos
VPVanessa Peynenburg
Vanessa Peynenburg
DTDavid Thiessen
David Thiessen
MNMarcie Nugent
Marcie Nugent
EKE. Karin
E. Karin
NTNick Titov
Nick Titov
While internet-delivered cognitive behavioural therapy (ICBT) is effective, some patients suggest extended support post-treatment could improve care. In this randomized factorial trial, we examined the benefits of an 8-week therapist-assisted ICBT program offered with or without an optional 4-week extension of support (Factor 1) and with or without an optional booster lesson (Factor 2). Patients screened for ICBT for depression and/or anxiety were randomly assigned to the conditions (N = 434) and we examined the use of the extension and booster, differences between those who did or did not use extension or booster, and the impact of the extension or booster on outcomes, engagement, and satisfaction at 26-weeks post-enrollment. Therapists recorded time and observations with offering support during the extension and booster. In the extension group, 54.4% (n = 56) requested the extension, while in the booster group 50.9% (n = 56) accessed the booster, and in the combined group, 41.6% (n = 47) requested the extension and 51.3% (n = 58) accessed the booster. Those who requested the extension were older, and more likely to report medication and mental health service use and severe mental health-related disability at pre-treatment; they also reported putting less effort into ICBT and finding skills more difficult. The booster was more often used among those with lower symptom severity, and those who put more effort into and had more positive experiences with ICBT. As expected, those assigned to extension sent more messages to their therapist, and those assigned to booster logged in more often. Therapists also took more time to deliver ICBT with an extension (>18 min) or booster (>13 min) compared to the 8-week program, and perceived extension and booster as beneficial for some, but not all patients. Treatment satisfaction was high across conditions, and effect sizes were large from pre-treatment to 26-week follow-up on most measures. No significant group differences were found in this study. Lack of group differences, however, could reflect low use of the extension and booster. Results provide helpful information about the demand for extensions and boosters, and provide directions for future research.

6 September 2022 in JMIR Formative Research
Verified
Journal Article
Open access
VSVictoria Suchan
Victoria Suchan
VPVanessa Peynenburg
Vanessa Peynenburg
DTDavid Thiessen
David Thiessen
MNMarcie Nugent
Marcie Nugent
BDBlake Dear
Blake Dear
HHHeather Hadjistavropoulos
Heather Hadjistavropoulos
Background: Postpartum depression (PPD) and postpartum anxiety (PPA) are often comorbid and are associated with significant personal and economic costs. Fewer than half of the mothers experiencing PPD or PPA symptoms receive face-to-face treatment, suggesting a need for alternative delivery formats such as internet-delivered cognitive behavioral therapy (ICBT). Objective: This pilot study aimed to examine the impact of a therapist-assisted, transdiagnostic ICBT program on symptoms of PPD and PPA, as there is only one previous study on transdiagnostic ICBT with this population, which did not include therapist assistance. Methods: Clients endorsing the symptoms of PPD or PPA (N=63) were randomized to an 8-week transdiagnostic ICBT course (Wellbeing Course for New Moms) or to treatment as usual (TAU). Clients completed measures of depression, anxiety, stress, postnatal bonding, and relationship satisfaction, as well as measures of treatment satisfaction and therapeutic alliance, before treatment, after treatment, and at the 1-month follow-up. Outcome measures were also completed at the 6-month follow-up for clients who completed the ICBT course. Results: Both the ICBT and TAU groups experienced statistically significant improvements over time. The ICBT group experienced larger improvements after treatment and at the 1-month follow-up on more measures than the TAU group, with medium between-group Cohen d effects on primary outcome measures for anxiety (Cohen d=0.65, 95% CI 0.13-1.17), PPD (Cohen d=0.52, 95% CI 0.01-1.04), and depression (Cohen d=0.56, 95% CI 0.05-1.08), and on secondary outcome measures of overall distress (Cohen d=0.69, 95% CI 0.17-1.21), anxiety (Cohen d=0.59, 95% CI 0.07-1.11), and stress (Cohen d=0.76, 95% CI 0.23-1.28). Time-by-group interactions for proportional reductions between groups over time were only significant after treatment and at the 1-month follow-up for the primary anxiety measure (P=.006). This study was underpowered for detecting small or medium effects. Overall, clients perceived the treatment as credible, and 95% (21/22) of the clients were satisfied with the treatment content and therapist support. Conclusions: Findings from this pilot study provide preliminary support for transdiagnostic ICBT in treating PPD and PPA symptoms to improve access to psychological treatments. Trial Registration: ClinicalTrials.gov NCT04012580; https://clinicaltrials.gov/ct2/show/NCT04012580

3 August 2022 in Journal of Behavioral Medicine
Verified
Journal Article
Open access
PDF file
SMS. H. Mehta
S. H. Mehta
MNMarcie Nugent
Marcie Nugent
VPVanessa Peynenburg
Vanessa Peynenburg
DTDavid Thiessen
David Thiessen
GPG. La Posta
G. La Posta
HHHeather Hadjistavropoulos
Heather Hadjistavropoulos
There is growing interest in offering Internet-delivered cognitive behaviour therapy (ICBT) to individuals with chronic health conditions, with this process often being guided by a single clinician. Due to lack of full time personnel, it is sometimes necessary to have multiple clinicians offer guidance or for no guidance to be offered. In this randomized trial, we compared team-guided ICBT (n = 90) to self-guided ICBT (n = 88). Participants completed measures at pre-, post-, and 3-months post-ICBT. Both groups showed similar rates of treatment completion and large improvements on depression and anxiety at post-treatment and follow-up. Unexpectedly, more participants in the self-guided versus team-guided condition showed clinically significant improvement on depression at post-treatment (76.5% vs 49.2%) and follow-up (70% vs 45.6%). Thus, team-guided ICBT may not provide significant benefits compared to self-guided ICBT. However, it may be an alternative approach to consider among a population of high risk individuals that wants or requires closer monitoring of symptoms.Trail registration TRN: NCT03500237; Date: April 18, 2018.

YFYvonne Nichole Faller
Yvonne Nichole Faller
VPVanessa Peynenburg
Vanessa Peynenburg
Eric Daniel TessierEric Daniel Tessier
Eric Daniel Tessier
DTDavid Thiessen
David Thiessen
HHHeather Hadjistavropoulos
Heather Hadjistavropoulos
Workplace accommodations can improve work functioning for employees with mental health concerns, yet few employees receive accommodations. The current study examined the benefits of providing education on workplace accommodations. In total, 89 participants with symptoms of depression and/or anxiety were randomized to an online psychoeducation course or wait-list control (WLC). The course provided education on symptoms, accommodations, tips for requesting accommodations and making disclosures, and coping strategies. Primary outcomes included the impact of the course on requesting and receiving accommodations, accommodation knowledge, self-stigma, and workplace relationships at 8 weeks post-randomization. Additional analyses examined the impact of the course on symptoms, absenteeism, presenteeism, and self-efficacy and whether supervisory leadership and organizational inclusivity impact disclosure and accommodation use. Participants in the course reported improvements in accommodation knowledge, self-efficacy, and presenteeism compared to the WLC. Both groups reported reduced self-stigma and increased disclosures over time. Specifically, partial disclosures were associated with supportive organizations and supervisors. No group differences were found on accommodation use, symptoms, workplace relationships, or comfort with disclosure. Few participants made accommodation requests, therefore a statistical analysis on requesting or receiving accommodations was not performed. Overall, providing psychoeducation has the potential to assist individuals with depression and anxiety who may require workplace accommodations, but further research is required.