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Dive into the research topics where Kfir Feffer is active.

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Featured researches published by Kfir Feffer.


The Lancet | 2018

Effectiveness of theta burst versus high-frequency repetitive transcranial magnetic stimulation in patients with depression (THREE-D): a randomised non-inferiority trial

Daniel M. Blumberger; Fidel Vila-Rodriguez; Kevin E. Thorpe; Kfir Feffer; Yoshihiro Noda; Peter Giacobbe; Yuliya Knyahnytska; Sidney H. Kennedy; Raymond W. Lam; Zafiris J. Daskalakis; Jonathan Downar

BACKGROUND Treatment-resistant major depressive disorder is common; repetitive transcranial magnetic stimulation (rTMS) by use of high-frequency (10 Hz) left-side dorsolateral prefrontal cortex stimulation is an evidence-based treatment for this disorder. Intermittent theta burst stimulation (iTBS) is a newer form of rTMS that can be delivered in 3 min, versus 37·5 min for a standard 10 Hz treatment session. We aimed to establish the clinical effectiveness, safety, and tolerability of iTBS compared with standard 10 Hz rTMS in adults with treatment-resistant depression. METHODS In this randomised, multicentre, non-inferiority clinical trial, we recruited patients who were referred to specialty neurostimulation centres based at three Canadian university hospitals (Centre for Addiction and Mental Health and Toronto Western Hospital, Toronto, ON, and University of British Columbia Hospital, Vancouver, BC). Participants were aged 18-65 years, were diagnosed with a current treatment-resistant major depressive episode or could not tolerate at least two antidepressants in the current episode, were receiving stable antidepressant medication doses for at least 4 weeks before baseline, and had an HRSD-17 score of at least 18. Participants were randomly allocated (1:1) to treatment groups (10 Hz rTMS or iTBS) by use of a random permuted block method, with stratification by site and number of adequate trials in which the antidepressants were unsuccessful. Treatment was delivered open-label but investigators and outcome assessors were masked to treatment groups. Participants were treated with 10 Hz rTMS or iTBS to the left dorsolateral prefrontal cortex, administered on 5 days a week for 4-6 weeks. The primary outcome measure was change in 17-item Hamilton Rating Scale for Depression (HRSD-17) score, with a non-inferiority margin of 2·25 points. For the primary outcome measure, we did a per-protocol analysis of all participants who were randomly allocated to groups and who attained the primary completion point of 4 weeks. This trial is registered with ClinicalTrials.gov, number NCT01887782. FINDINGS Between Sept 3, 2013, and Oct 3, 2016, we randomly allocated 205 participants to receive 10 Hz rTMS and 209 participants to receive iTBS. 192 (94%) participants in the 10 Hz rTMS group and 193 (92%) in the iTBS group were assessed for the primary outcome after 4-6 weeks of treatment. HRSD-17 scores improved from 23·5 (SD 4·4) to 13·4 (7·8) in the 10 Hz rTMS group and from 23·6 (4·3) to 13·4 (7·9) in the iTBS group (adjusted difference 0·103 [corrected], lower 95% CI -1·16; p=0·0011), which indicated non-inferiority of iTBS. Self-rated intensity of pain associated with treatment was greater in the iTBS group than in the 10 Hz rTMS group (mean score on verbal analogue scale 3·8 [SD 2·0] vs 3·4 [2·0] out of 10; p=0·011). Dropout rates did not differ between groups (10 Hz rTMS: 13 [6%] of 205 participants; iTBS: 16 [8%] of 209 participants); p=0·6004). The most common treatment-related adverse event was headache in both groups (10 Hz rTMS: 131 [64%] of 204; iTBS: 136 [65%] of 208). INTERPRETATION In patients with treatment-resistant depression, iTBS was non-inferior to 10 Hz rTMS for the treatment of depression. Both treatments had low numbers of dropouts and similar side-effects, safety, and tolerability profiles. By use of iTBS, the number of patients treated per day with current rTMS devices can be increased several times without compromising clinical effectiveness. FUNDING Canadian Institutes of Health Research.


Journal of Psychopharmacology | 2017

Novelty-seeking trait predicts the effect of methylphenidate on creativity.

Hila Z. Gvirts; Naama Mayseless; Aviv Segev; D Yael Lewis; Kfir Feffer; Yael Barnea; Yuval Bloch; Simon G Shamay-Tsoory

In recent years the use of psychostimulants for cognitive enhancement in healthy individuals with no psychiatric disorders has been on the rise. However, it is still unclear whether psychostimulants improve certain cognitive functions at the cost of others, and how these psychostimulants interact with individual personality differences. In the current study, we investigated whether the effect of one common stimulant, methylphenidate (MPH), on creativity is associated with novelty seeking. Thirty-six healthy adults, without attention-deficit hyperactivity disorder (ADHD) symptomology, were assigned randomly in a double-blind fashion to receive MPH or placebo. We found that the effect of MPH on creativity was dependent on novelty-seeking (NS) personality characteristics of the participants. MPH increased creativity in individuals with lower NS, while it reduced creativity levels in individuals with high NS. These findings highlight the role of the dopaminergic system in creativity, and indicate that among healthy individuals NS can be seen as a predictor of the effect of MPH on creativity.


General Hospital Psychiatry | 2016

A comparative study with depressed patients on the acceptability of placebo use

Kfir Feffer; Pesach Lichtenberg; Gideon Becker; Yuval Bloch; Roni Netzer; Uri Nitzan

OBJECTIVE High rates of placebo responses are consistently reported in patients with major depressive disorder. Nonetheless, treating depression with placebo is still ethically controversial and generally prohibited in the clinical setting. In the present study, we assess the acceptability of placebo usage among depressed patients. METHOD Ninety-six outpatients with major depressive disorder were matched to 114 healthy controls. After a thorough explanation of the placebo effect, its efficacy and limitations in the treatment of depression, the study participants completed a 32-item self-report questionnaire. The five core questions addressed the attitude and willingness of subjects to be treated with a placebo in the clinical setting. RESULTS Among study group patients, the majority (56.7%) conveyed consent for placebo treatment if they were to suffer another depressive episode. Both study group and control group expressed high rates of willingness to waive their right to informed consent (55.6% and 50%, respectively), and they did not consider placebo treatment to be a deceit (56%) or to diminish their sense of autonomy (56.7%). CONCLUSIONS Most patients with depression are willing to waive their right to informed consent in order to receive placebo treatment. These findings should encourage further studies of placebo usage and its legitimacy in clinical practice.


Psychiatry Research-neuroimaging | 2016

A possible effect of methylphenidate on state anxiety: A single dose, placebo controlled, crossover study in a control group

Aviv Segev; Hila Z. Gvirts; Kevin Strouse; Naama Mayseless; Hagar Gelbard; Yael Doreen Lewis; Yael Barnea; Kfir Feffer; Simone G. Shamay-Tsoory; Yuval Bloch

Methylphenidate affects state-anxiety in ADHD patients. The current study examines the effect of Methylphenidate on state-anxiety in healthy subjects. In a cross-over, randomized, controlled, double-blind study, 36 healthy subjects received either Methylphenidate or placebo. As a group, no change in state-anxiety was detected with Methylphenidate. However, participants reporting higher anxiety levels experienced a significant and specific state-anxiety reduction following Methylphenidate. Moreover, a strong negative correlation was found between the initial-level of anxiety and net-change in state-anxiety. These changes were unrelated to self-perceived attention levels. Our results point to the state-dependent effects of Methylphenidate on anxiety.


Journal of Nervous and Mental Disease | 2013

Consenting not to be informed: a survey on the acceptability of placebo use in the treatment of depression.

Uri Nitzan; Kfir Feffer; Yuval Bloch; Pesach Lichtenberg; Shaul Lev-Ran; Gideon Becker; Samuel Wolfman; Shmuel Fennig

Abstract The aim of this study was to investigate the opinions of healthy students regarding the acceptability of placebo treatment if they were to experience depression. A survey was conducted among 344 students in five academic centers in Israel. After a thorough explanation of the placebo effect, its efficacy and limitations in the treatment of depression, the study participants completed a 32-item self-report questionnaire. Seventy percent (n = 243) of the participants answered that they would agree to treatment with a placebo as a first-line treatment if they were to experience depression in the future. Eighty-eight percent (n = 297) of the subjects did not think that a physician who administered placebos was deceitful. Once aware of the possible benefits and limitations of placebo treatment, most of our study population was willing to accept placebo as a legitimate treatment of depression. Additional studies on the possible use of placebo as an effective, safe, and acceptable form of therapy are warranted.


European Psychiatry | 2017

Factors associated with response after deep transcranial magnetic stimulation in a real-world clinical setting: Results from the first 40 cases of treatment-resistant depression

Kfir Feffer; K.A.B. Lapidus; Yoram Braw; Yuval Bloch; S. Kron; R. Netzer; U. Nitzan

BACKGROUND Deep transcranial magnetic stimulation (dTMS) has been sanctioned by the United States Food and Drug Administration for treatment-resistant depression. In a retrospective cohort study, we evaluated response and effectiveness of dTMS in real-world practice, as an add-on treatment for resistant depression. METHODS Forty adult outpatients suffering from depression, all taking psychiatric medications, underwent 20 dTMS treatments over a 4-6 week period. At baseline (T0), visit 10 (T1), and visit 20 (T2), the Clinical Global Impression-Severity (CGI-S) scale was administered, and the Clinical Global Impression Improvement (CGI-I) scale was completed at T1 and T2; the Hamilton Depression Rating Scale (HDRS-21) was administrated at T0 and T2 only. The patients also completed the Quick Inventory of Depressive Symptoms-Self-Report (QIDS-SR) at T0, T1, and T2. RESULTS Depressive symptoms (HDRS-21 total score) decreased significantly following treatment. The HDRS total score decreased from an average of 21.22 (±6.09) at T0, to 13.95 (±7.24) at T2. Correspondingly, at T2, 32.5% were responders to the treatment and 20% were in remission, based on the HDRS-21. Treatment was well tolerated, with a discontinuation rate of 7.5%. While depressive symptoms at baseline did not predict remission/response at T2, higher HDRS scores at T0 were associated with a larger decrease in depressive symptoms during the study. CONCLUSIONS Significant antidepressant effects were seen following 20 dTMS treatments, given as augmentation to ongoing medications in treatment-resistant depression. The findings suggest that among patients with TRD, the severity of the depressive episode (and not necessarily the number of failed antidepressant medication trials) is associated with a positive therapeutic effect of dTMS. Hence, the initial severity of the depressive episode may guide clinicians in referring patients for dTMS.


Journal of Ect | 2018

Improvements in Health-Related Quality of Life With Electroconvulsive Therapy: A Meta-Analysis

Peter Giacobbe; Uros Rakita; Kirsten Penner-Goeke; Kfir Feffer; Alastair J. Flint; Sidney H. Kennedy; Jonathan Downar


European Psychiatry | 2011

FC31-02 - Is it ethical not to prescribe placebo? the patient’s perspective on the usage of placebo for the treatment of depression - a comparative study

Kfir Feffer; Uri Nitzan; Pesach Lichtenberg; Shaul Lev-Ran; Shmuel Fennig


International Clinical Psychopharmacology | 2018

The effect of methylphenidate on decision making in patients with borderline personality disorder and attention-deficit/hyperactivity disorder

Hila Z. Gvirts; Yael Doreen Lewis; Shira Dvora; Kfir Feffer; U. Nitzan; Ziv Carmel; Yechiel Levkovitz; Hagai Maoz


Biological Psychiatry | 2018

222. Clinical Results From the Theta Burst Versus High Frequency Repetitive Transcranial Magnetic Stimulation Effectiveness Evaluation in Depression (THREE-D) Randomized Non-Inferiority Trial

Daniel M. Blumberger; Fidel Vila-Rodriguez; Kevin E. Thorpe; Kfir Feffer; Yoshihiro Nodaa; Peter Giacobbe; Yuliya Knyahnytska; Sidney H. Kennedy; Raymond W. Lam; Zafiris J. Daskalakis; Jonathan Downar

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Pesach Lichtenberg

Hebrew University of Jerusalem

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Daniel M. Blumberger

Centre for Addiction and Mental Health

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