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Dive into the research topics where Kenneth A. Kobak is active.

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Featured researches published by Kenneth A. Kobak.


Psychotherapy and Psychosomatics | 2002

Obsessive-Compulsive Symptom Dimensions as Predictors of Compliance with and Response to Behaviour Therapy: Results from a Controlled Trial

David Mataix-Cols; Isaac Marks; John H. Greist; Kenneth A. Kobak; Lee Baer

Background: Recent factor-analytic studies in obsessive-compulsive disorder (OCD) identified consistent symptom dimensions. Support for the validity of these dimensions comes from studies of psychiatric comorbidity, functional brain imaging, genetic transmission, and treatment response to medications. This study examined whether previously identified OCD symptom dimensions are associated with treatment compliance and response to behaviour therapy (BT) for OCD. Methods: One hundred and fifty-three OCD outpatients who participated in a multi-centre randomised controlled trial of computer- versus clinician-guided BT for OCD were included in the study. Logistic and multiple regression models tested for significant predictors of compliance with and response to BT and relaxation. Results: The patients studied were phenomenologically comparable (including the presence of ‘pure’ obsessions and mental rituals) to those in previous serotonin reuptake inhibitor (SRI) trials and those in clinical epidemiology studies. High scorers on the ‘hoarding’ dimension were more likely to drop out prematurely from the study and tended to improve less. For those completing treatment, the strongest predictor of outcome was pre-treatment severity. Initial depression scores were unrelated to outcome. After controlling for symptom severity, higher scores on the ‘sexual/religious obsessions’ factor predicted poorer outcome with BT, especially when computer-guided. Conclusions: BT is especially indicated for OCD patients with aggressive/checking, contamination/cleaning and symmetry/ordering symptoms. Previous accounts of unsuccessful BT in patients with hoarding symptoms may be due in part to their propensity to drop out earlier from treatment. Patients with sexual/religious obsessions, but not those with mental rituals, might respond less well to traditional BT techniques. Existing treatments need to be refined and/or new treatments developed to improve these patients’ adherence and response to treatment.


International Clinical Psychopharmacology | 2008

The GRID-HAMD: standardization of the Hamilton Depression Rating Scale.

Janet B. W. Williams; Kenneth A. Kobak; Per Bech; Nina Engelhardt; Ken Evans; Joshua D. Lipsitz; Jason Olin; Jay Pearson; Amir H. Kalali

This report describes the GRID-Hamilton Depression Rating Scale (GRID-HAMD), an improved version of the Hamilton Depression Rating Scale that was developed through a broad-based international consensus process. The GRID-HAMD separates the frequency of the symptom from its intensity for most items, refines several problematic anchors, and integrates both a structured interview guide and consensus-derived conventions for all items. Usability was established in a small three-site sample of convenience, evaluating 29 outpatients, with most evaluators finding the scale easy to use. Test–retest (4-week) and interrater reliability were established in 34 adult outpatients with major depressive disorder, as part of an ongoing clinical trial. In a separate study, interrater reliability was found to be superior to the Guy version of the HAMD, and as good as the Structured Interview Guide for the Hamilton Depression Rating Scale (SIGH-D), across 30 interview pairs. Finally, using the SIGH-D as the criterion standard, the GRID-HAMD demonstrated high concurrent validity. Overall, these data suggest that the GRID-HAMD is an improvement over the original Guy version as well as the SIGH-D in its incorporation of innovative features and preservation of high reliability and validity.


International Clinical Psychopharmacology | 2005

St John's wort versus placebo in obsessive–compulsive disorder: results from a double-blind study

Kenneth A. Kobak; Leslie V. H. Taylor; Alexander Bystritsky; Cary J. Kohlenberg; John H. Greist; Phebe Tucker; Gemma Warner; Rise Futterer; Tanya Vapnik

Although St Johns wort (Hypericum perforatum) is one of the most widely used and studied herbal medicines for depression, less is known about its efficacy in anxiety disorders, in spite of the fact that patients with anxiety disorders are among the most likely to self-medicate using alternative treatments. Pharmacokinetic evidence for the serotonergic, domaminergic and GABAminergic activity of hypericum, and a recent successful open-label study, suggests that it may be effective for obsessive–compulsive disorder (OCD). Sixty subjects were randomized to 12 weeks of treatment with St Johns wort (LI 160) or matching placebo. Subjects with Hamilton Depression Scale scores of 16 or above were excluded. A flexible-dose schedule was utilized (600–1800u2009mg/day). The mean change on the Yale–Brown Obsessive–Compulsive Scale (Y-BOCS) with St Johns wort (3.43) was not significantly different than the mean change found with placebo (3.60) (P=899). No significant differences were found on any of the Y-BOCS subscales. The percentage of patients rated as ‘much’ or ‘very much’ improved at endpoint was not significantly different between St Johns wort (17.9%) and placebo (16.7%) (P=0.905). Only one patient from each group discontinued due to adverse events [sinus infection (St Johns wort); confusion (placebo)]. The results fail to support the efficacy of St Johns wort for OCD.


Journal of Clinical Psychopharmacology | 2010

Site versus centralized raters in a clinical depression trial: impact on patient selection and placebo response.

Kenneth A. Kobak; Andrew F. Leuchter; David J. DeBrota; Nina Engelhardt; Janet B. W. Williams; Ian A. Cook; Andrew C. Leon; Jonathan E. Alpert

The use of centralized raters who are remotely linked to sites and interview patients via videoconferencing or teleconferencing has been suggested as a way to improve interrater reliability and interview quality. This study compared the effect of site-based and centralized ratings on patient selection and placebo response in subjects with major depressive disorder. Subjects in a 2-center placebo and active comparator controlled depression trial were interviewed twice at each of 3 time points: baseline, 1-week postbaseline, and end point-once by the site rater and once remotely via videoconference by a centralized rater. Raters were blind to each others scores. A site-based score of greater than 17 on the 17-item Hamilton Depression Rating Scale (HDRS-17) was required for study entry. When examining all subjects entering the study, site-based raters HDRS-17 scores were significantly higher than centralized raters at baseline and postbaseline but not at end point. At baseline, 35% of subjects given an HDRS-17 total score of greater than 17 by a site rater were given an HDRS total score of lower than 17 by a centralized rater and would have been ineligible to enter the study if the centralized raters score was used to determine study entry. The mean placebo change for site raters (7.52) was significantly greater than the mean placebo change for centralized raters (3.18, P < 0.001). Twenty-eight percent were placebo responders (>50% reduction in HDRS) based on site ratings versus 14% for central ratings (P < 0.001). When examining data only from those subjects whom site and centralized raters agreed were eligible for the study, there was no significant difference in the HDRS-17 scores. Findings suggest that the use of centralized raters could significantly change the study sample in a major depressive disorder trial and lead to significantly less change in mood ratings among those randomized to placebo.


Journal of Psychiatric Research | 2003

Development of a standardized training program for the Hamilton Depression Scale using internet-based technologies: results from a pilot study

Kenneth A. Kobak; Joshua D. Lipsitz; Alan Feiger

Poor inter-rater reliability is a major concern, contributing to error variance, which decreases power and increases the risk for failed trials. This is particularly problematic with the Hamilton Depression Scale (HAMD), due to lack of standardized questions or explicit scoring procedures. Establishing standardized procedures for administering and scoring the HAMD is typically done at study initiation meetings. However, the format and time allotted is usually insufficient, and evaluation of the trainees ability to actually conduct a clinical interview is limited. To address this problem, we developed a web-based, interactive rater education program for standardized training to diverse sites in multi-center trials. The program includes both didactic training on scoring conventions and live, remote observation of trainees applied skills. The program was pilot tested with nine raters from a single site. Results found a significant increase in didactic knowledge pre-to-post testing, with the mean number of incorrect answers decreasing from 6.5 (S.D.=1.64) to 1.3 (S.D.=1.03), t(5)=7.35, P=0.001 (20 item exam). Seventy-five percent of the trainees interviews were within two points of the trainers score. Inter-rater reliability (intraclass correlation) (based on trainees actual interviews) was 0.97, P<0.0001. Results support the feasibility of this methodology for improving rater training. An NIMH funded study is currently underway examining this methodology in a multi-site trial.


Annals of General Psychiatry | 2011

The use of videoconferencing with patients with psychosis: a review of the literature.

Ian R. Sharp; Kenneth A. Kobak; Douglas A Osman

Videoconferencing has become an increasingly viable tool in psychiatry, with a growing body of literature on its use with a range of patient populations. A number of factors make it particularly well suited for patients with psychosis. For example, patients living in remote or underserved areas can be seen by a specialist without need for travel. However, the hallmark symptoms of psychotic disorders might lead one to question the feasibility of videoconferencing with these patients. For example, does videoconferencing exacerbate delusions, such as paranoia or delusions of reference? Are acutely psychotic patients willing to be interviewed remotely by videoconferencing? To address these and other issues, we conducted an extensive review of Medline, PsychINFO, and the Telemedicine Information Exchange databases for literature on videoconferencing and psychosis. Findings generally indicated that assessment and treatment via videoconferencing is equivalent to in person and is tolerated and well accepted. There is little evidence that patients with psychosis have difficulty with videoconferencing or experience any exacerbation of symptoms; in fact, there is some evidence to suggest that the distance afforded can be a positive factor. The results of two large clinical trials support the reliability and effectiveness of centralized remote assessment of patients with schizophrenia.


Depression and Anxiety | 2008

Face‐to‐face versus remote administration of the Montgomery–Asberg Depression Rating Scale using videoconference and telephone

Kenneth A. Kobak; Janet B. W. Williams; Elizabeth L. Jeglic; Donna Salvucci; Ian R. Sharp

Although the use of telemedicine in psychiatry has a long history in providing clinical care to patients, its use in clinical trials research has not yet been commonly employed. Telemedicine allows for the remote assessment of study patients, which could be done by a centralized, highly calibrated, and impartial cohort of raters independent of the study site. This study examined the comparability of remote administration of the Montgomery–Asberg Depression Rating Scale (MADRS) by videoconference and by telephone to traditional face‐to‐face administration. Two parallel studies were conducted: one compared face‐to‐face with videoconference administration (N=35), and the other compared face‐to‐face with telephone administration (N=35). In each study, depressed patients were interviewed independently twice: once in the traditional face‐to‐face manner, and the second time by either videoconference or teleconference. A counterbalanced order was used. The mean MADRS score for interviews conducted remotely by videoconference was not significantly different from the mean MADRS scores conducted by face‐to‐face administration (mean difference=0.51 points), P=.388, intraclass correlation (ICC)=.94, P<0001. Similarly, the mean MADRS score for interviews conducted by telephone was not significantly different from the mean MADRS score conducted by face‐to‐face administration (mean difference=0.74 points), P=.270, ICC=.93, P<0001. Results of the study support the comparability of remote administration of the MADRS, by both telephone and videoconference, to face‐to‐face administration. Comparability of the administration mode allows for remote assessment of patients in both research and clinical applications. Depression and Anxiety, 2008.


Journal of Clinical Psychopharmacology | 2009

Sources of unreliability in depression ratings.

Kenneth A. Kobak; Brianne Brown; Ian R. Sharp; Hollie Levy-Mack; Kurrie Wells; Felice Okum; Janet B. W. Williams

Background: Good interrater reliability is essential to minimize error variance and improve study power. Reasons why raters differ in scoring the same patient include information variance (different information obtained because of asking different questions), observation variance (the same information is obtained, but raters differ in what they notice and remember), interpretation variance (differences in the significance attached to what is observed), criterion variance (different criteria used to score items), and subject variance (true differences in the subject). We videotaped and transcribed 30 pairs of interviews to examine the most common sources of rater unreliability. Method: Thirty patients who experienced depression were independently interviewed by 2 different raters on the same day. Raters provided rationales for their scoring, and independent assessors reviewed the rationales, the interview transcripts, and the videotapes to code the main reason for each discrepancy. One third of the interviews were conducted by raters who had not administered the Hamilton Depression Rating Scale before; one third, by raters who were experienced but not calibrated; and one third, by experienced and calibrated raters. Results: Experienced and calibrated raters had the highest interrater reliability (intraclass correlation [ICC]; r = 0.93) followed by inexperienced raters (r = 0.77) and experienced but uncalibrated raters (r = 0.55). The most common reason for disagreement was interpretation variance (39%), followed by information variance (30%), criterion variance (27%), and observation variance (4%). Experienced and calibrated raters had significantly less criterion variance than the other cohorts (P = 0.001). Conclusions: Reasons for disagreement varied by level of experience and calibration. Experienced and uncalibrated raters should focus on establishing common conventions, whereas experienced and calibrated raters should focus on fine tuning judgment calls on different thresholds of symptoms. Calibration training seems to improve reliability over experience alone. Experienced raters without cohort calibration had lower reliability than inexperienced raters.


Annals of General Psychiatry | 2015

Integrating technology into cognitive behavior therapy for adolescent depression: a pilot study

Kenneth A. Kobak; James C. Mundt; Betsy D. Kennard

AbstractBackgroundnRapid advances in information technology and telecommunications have resulted in a dramatic increase in the use of mobile devices and the internet to enhance and facilitate access to treatment. Cognitive behavior therapy (CBT) is an empirically based treatment that is well suited for enhancement by new technologies, particularly with youth. To facilitate the dissemination of this evidence-based treatment, we developed a technology-enhanced CBT intervention for the treatment of adolescent depression consisting of (1) online therapist training (2) in-session use of tablets for teaching clients CBT concepts and skills, and (3) text messaging for between session homework reminders and self-monitoring.MethodsEighteen licensed clinicians (social workers nxa0=xa07, psychologists nxa0=xa09) were randomized to have their patients receive either the intervention (CBT) or treatment as usual (TAU). Each clinician treated four adolescents for 12xa0weeks. Clinicians in the CBT arm completed an online tutorial on CBT treatment of adolescent depression, then received an iPad with access to patient education materials for teaching CBT concepts to patients during sessions. Individualized text messages were integrated into treatment for homework reminders, support, and outcomes measurement. Outcome measures included a 49-item multiple choice test for tutorial effectiveness; the system usability scale (SUS) for user satisfaction; quick inventory of depressive symptomatology–adolescent version (QIDS-A-Pat); and clinician and patient ratings on the therapeutic alliance scale for adolescents (TASA).ResultsA significant increase in knowledge of CBT concepts was found after completing the tutorial, t(8)xa0=xa07.02, pxa0<xa00.001. Clinician and patient ratings of user satisfaction were high for both the iPad teaching tools, and the text messaging. Ninety-five percent of teens said reviewing their text messages with their therapist was helpful, and all said they would use text messaging in treatment again. Ratings of the therapeutic alliance were higher in the CBT arm t(131)xa0=xa04.03, pxa0=xa00.001. A significant reduction in depression was found in both groups [t(34)xa0=xa08.453, pxa0<xa00.001 and t(29)xa0=xa06.67, pxa0<xa00.001 for CBT and TAU, respectively). Clinical ratings of improvement were greater on all outcome measures for the CBT arm; however, none reached statistical significance. Effect sizes (Cohen’s d) ranged from small (QIDS-A) to large (TASA). ConclusionsResults support the feasibility of this technology-enhanced CBT intervention as a means of improving CBT treatment of adolescent depression and may help address the critical shortage of therapists trained on empirically based treatments.


Archives of Family Medicine | 2000

Randomized Trial of a Depression Management Program in High Utilizers of Medical Care

David J. Katzelnick; Gregory E. Simon; Steven D. Pearson; Willard G. Manning; Cindy P. Helstad; Henry J. Henk; Stanley M. Cole; Elizabeth Lin; Leslie V. H. Taylor; Kenneth A. Kobak

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Ian R. Sharp

University of Pennsylvania

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John H. Greist

University of Wisconsin-Madison

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Henry J. Henk

Group Health Cooperative

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Steven D. Pearson

National Institutes of Health

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