Perceptual Retraining to Reduce Suicide Risk (PRS)

Florida State University

Status: Completed

Conditions: Perceptual Olfactory Bias

Treatments: Behavioral: Sham Neutral training; Behavioral: Perceptual Retraining Treatment

Study type: Interventional

Funder types: Other; Other U.S. Federal agency

Identifiers

NCT02845700

A-16054.13a

Details and patient eligibility

About

The study will use a prospective design consisting of three phases. The phases are:

1. the development of the perceptual retraining treatment (PRT),
2. the evaluation of the treatment's feasibility and acceptability, and
3. an assessment of its efficacy.

During the third phase, a pilot study will be conducted in which participants will be randomly assigned to either PRT or a waitlist control group in order to assess efficacy. Diagnostic information and eligibility criteria will be assessed using the Structured Clinical Interview for Diagnostic and Statistical Manual (DSM) 4th ed. (SCID) and the Clinician Administered PTSD Scale for DSM-5 (CAPS-5).

Full description

This study will use clinical interviews, self-report measures, and behavioral assessments to evaluate the efficacy of the PRT protocol. The study will recruit approximately 30 veterans. The primary inclusionary criterion will be that participants must show some evidence of olfactory perceptual bias toward military-relevant stimuli (e.g., burning rubber, decay, fuel). Investigators are not requiring current suicidal ideation as an entry criterion because investigators believe that a fair percentage of veterans will have some suicidal ideation/intent but making this an entry requirement will limit the investigators ability to recruit given the tight timeline for the study.

The study will consist of the development and evaluation of a novel intervention. The essential feature of this intervention is the use of a gradient of triggering smells (e.g., burning rubber, decay, fuel, etc.), to which participants will be systematically exposed in an effort to facilitate habituation to these odors. The PRT protocol will be administered over two 1-hour sessions. Participants will return 1 month after their final PRT protocol session to complete a battery of follow-up measures, as well as the CAPS-5.

The primary outcome measures of interest are: olfactory perceptual bias (as measured by the olfactory bias assessment), suicidal ideation and behaviors (as measured by the Beck Suicide Scale and Depressive Symptom Inventory- Suicidality Subscale), and symptoms related to suicide, such as anxiety and trauma (as measured by the Beck Anxiety Inventory and PTSD Checklist for DSM-5, respectively).

Enrollment: 13 patients

Sex: All

Ages: 18 to 60 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• evidence of olfactory perceptual bias toward military-relevant stimuli (e.g., burning rubber, decay, fuel).
• military combat exposure in Operation Iraqi Freedom, Enduring Freedom, or New Dawn.
• Age 18-60.

Exclusion criteria

• Significant medical illness that compromises olfactory perception or tolerance (e.g., significant olfactory disease or dysfunction, cardiovascular disease, respiratory disorders, renal disease, epilepsy, stroke, and uncontrolled hypertension or migraines).
• Evidence of imminent suicidal intent
• Evidence of current or past psychotic-spectrum disorders, or uncontrolled bipolar disorder.
• English speakers.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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13 participants in 2 patient groups, including a placebo group

Perceptual Retraining Treatment (PRT)

Active Comparator group

Description:

The Perceptual Retraining Treatment will involve systematic presentation of diluted malodors. For each individual, vials on either side of their initial ideographic detection threshold will be presented. During the retraining, participants will be given feedback to shift their bias away from the malodorous target stimuli. For example, in the context of diluted solutions participants will be given the feedback that they are "correct" when a "neutral" response is given to solutions that are above the starting threshold (stronger malodor) and "incorrect" when a target is endorsed that is below the starting threshold (weaker malodor). Each training session will consist of 4 training blocks.

Treatment:

Behavioral: Perceptual Retraining Treatment

Sham Neutral Training (SNT)

Placebo Comparator group

Description:

Approximately half of the participants will be randomized to the SNT condition designed to control for the effects of time and learning. In the SNT condition, participants will complete the same assessments (including the olfactory bias assessment), as well as a sham training consisting of neutral/neutral odor pairing dilutions, rather than the combat/neutral odor pairings as in the PRT. Following the one-month assessment, they will be given the option to complete the PRT.

Treatment:

Behavioral: Sham Neutral training