The Effect Of Prefrontal Transcranial Direct Current Stimulation On Clinical Severity, Attentional Bias and Interoceptive Accuracy In Panic Disorder
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Panic Disorder
- Sponsor
- Istanbul University
- Enrollment
- 30
- Locations
- 1
- Primary Endpoint
- Changes in Panic Disorder Severity Scale (PDSS) scores
- Status
- Completed
- Last Updated
- 3 years ago
Overview
Brief Summary
The aim of the present study is to investigate the effect of prefrontal transcranial Direct Current Stimulation (tDCS) on clinical severity, attentional bias and interoceptive accuracy in panic disorder (PD).
The participants will be assigned to active and sham groups (1:1) and will receive 10 sessions of tDCS. The study will also examine if the effects may last for a month.
Detailed Description
Panic Disorder (PD) is one of the most common anxiety disorders. In spite of several available medications, there are unsatisfactory outcomes in a considerable proportion of PD patients and novel treatment approaches are lacking. Given that response to pharmacotherapeutical and psychological treatments occur after long intervals and medications may cause substantial adverse effects which may affect treatment compliance, fast acting and well-tolerated treatments such as non-invasive brain stimulation are considered to be useful as primary treatment approach or as an add-on treatment in PD. Repetitive Transcranial Magnetic Stimulation (rTMS) trials targeting prefrontal cortex mostly reported favorable outcomes in PD. Transcranial Direct Current Stimulation (tDCS) is another promising non-invasive brain stimulation method with numerous distinctive aspects including its low-cost, robust safety and tolerability, low dropout rates, easy application, reliable blinding procedures and the opportunity to use concomitantly with other treatments. Left anodal/right anodal tDCS over the dorsolateral prefrontal cortex has been demonstrated to decrease attentional bias and amygdala reactivity to threat in individuals with high trait anxiety. Moreover, a treatment-resistant case of PD was reported to have significant amelioration of symptoms up to one month after 10 sessions of tDCS. The study is a triple-blind randomized controlled trial. The sample will be consisted of thirty participants diagnosed as having PD due to Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria. The participants will be assigned to active or sham groups equally. Clinical severity will be assessed with adequate scales. Emotion recognition, attentional bias to threat and interoceptive accuracy will also be measured. Then, participants will be applied ten active or sham sessions of left anodal/right cathodal tDCS over the dorsolateral prefrontal cortex (DLPFC). All measurements will be repeated after the applications. Succinctly, the aim of this study is to assess the effect of ten sessions left anodal/right cathodal tDCS over the DLPFC on clinical severity, attentional bias and interoceptive accuracy in PD.
Investigators
Raşit Tükel
Clinical Professor
Istanbul University
Eligibility Criteria
Inclusion Criteria
- •Patients with a primary diagnosis of Panic Disorder, as confirmed by the Structured Clinical Interview for the DSM-5 (SCID-5);
- •Patients currently on medication must be at the same stable dose(s) for one month prior to enrollment and be willing to continue at the same dose(s) through the duration of the study;
- •Right-hand dominancy assessed by Edinburgh Handedness Inventory;
- •Willingness and ability to comply with the requirements of the study protocol;
- •Naïve to tDCS.
- •5 or more years of education
Exclusion Criteria
- •Illiteracy, deficient language or refusal to participate or being not able to follow instructions or complete study tasks;
- •Less than 5 years of education
- •Individuals with any current or lifetime diagnosis of other Axis I disorders, as confirmed by the Structured Clinical Interview for the DSM-5 (SCID-5);
- •History of substance or psychoactive compound use,with the exception of nicotine consumption;
- •The presence of mental retardation diagnosis (previously identified)
- •Individuals with a clinically defined neurological disorder, with an increased risk of seizure for any reason, with a history of treatment with rTMS, deep brain stimulation for any disorder will be excluded;
- •Any personal or family history (1st degree relatives) of seizures other than febrile childhood seizures
- •Personal history of head trauma that resulted in loss of consciousness for \> 5 minutes and retrograde amnesia for \> 30 minutes;
- •Significant hearing loss or visual impairment;
- •Diagnosis of any serious or uncontrolled medical condition such as chronic obstructive pulmonary disease, congestive heart failure or renal failure;
Outcomes
Primary Outcomes
Changes in Panic Disorder Severity Scale (PDSS) scores
Time Frame: Up to one month
The PDSS consists of seven items, each rated on a 5-point scale, which ranges from 0 to 4. The items assess panic frequency, resulting distress, panic-focused anticipatory anxiety, phobic avoidance of situations and of physical sensations, impairment in occupational and social functioning. The overall assessment is made by a total score, which is calculated by summing the scores for all seven items. Minimum score is 0 and maximum score is 28. Higher scores indicate high levels of panic symptomatology. Reduction in score from baseline indicates clinical improvement of panic symptoms.
Changes in Hamilton Anxiety Rating Scale (HAM-A) scores
Time Frame: Up to one month
The Hamilton Anxiety Rating Scale (HAM-A) is a multiple item questionnaire used to provide an indication of anxiety severity. Higher scores indicate high levels of symptomatology. Minimum score is 0 and maximum score is 56. Reduction in score from baseline indicates clinical symptom improvement.
Changes in Clinical Global Impression-Severity (CGI-S) scores
Time Frame: Up to one month
Higher scores indicate the presence of high symptom severity. Decrease in scores from baseline reflects clinical symptom improvement. Minimum score is 1 and maximum score is 7. Patients will be classified as responders with a CGI-S = 1 or 2; and partial responders CGI-S = 3.
Changes in performance on an attentional dot-probe task
Time Frame: Up to one month
Computerized "dot-probe " attentional task will be used. Pairs of emotional faces (neutral/angry or neutral/happy) are randomly presented on a screen. Then, a probe is presented. Subjects are asked to indicate which side the probe approved and need to press the dot after the probe. Total time spent on Region of Interest (angry/neutral face) is measured. Attentional bias towards threat score is the subtraction of median reaction times (milliseconds) in congruent angry versus neutral trials from incongruent angry versus neutral trials. Minimum score is -1000 and maximum score is 1000. Positive scores indicate the presence of attentional vigilance towards threat whereas negative scores indicate an attentional avoidance towards threat.
Secondary Outcomes
- Changes in Hamilton Depression Rating Scale (HAM-D) scores(Up to one month)
- Changes in Sheehan Disability Scale (SDS) Social Life scores(Up to one month)
- Changes in Body Vigilance Scale (BVS) scores(Up to one month)
- Changes in the number of correct responses at a facial expression recognition task(Up to one month)
- Changes in Beck Depression Inventory (BDI) scores(Up to one month)
- Changes in Sheehan Disability Scale (SDS) Work/School scores(Up to one month)
- Changes in Sheehan Disability Scale (SDS) Family Life/Home Responsibilities scores(Up to one month)
- Changes in Heartbeat Detection Accuracy(Up to one month)