Social Disconnection Study

Role of Synaptic Density in Mediating the Relation Between Social Disconnection and Late-life Suicide Risk

The purpose of this research study is to examine the effect of social connectedness on the brain. Study procedures include one Magnetic Resonance Imaging (MRI) or functional Magnetic Resonance Imaging (fMRI) scan, one Positron Emission Tomography (PET) scan, one Magnetic Resonance Spectroscopy (MRS) scan, an electroencephalogram (EEG), and in-person and phone call follow-ups.

Study Overview

• Status: Recruiting
• Conditions: Social Disconnection

Detailed Description

The purpose of this study is to examine the effect of social connectedness (social isolation and loneliness) on synaptic density in the brain using PET scans. Participants will have a screening appointment to determine eligibility. Participants will participate in the following study procedures:

MRI or fMRI scan: the purpose of the MR scan is to help us identify the different regions of the brain on the PET scans. Participants may be asked to do some cognitive and behavioral tasks during parts of the MR scan.

PET scan: an arterial catheter and one or two IV catheters will be placed (one for radiotracer injection and one to take blood samples). The radiotracer, [18F]SDM-8 will be used. A radiotracer is a minimal amount of a drug that is labeled with a very small amount of a radioactive substance that binds to receptors in the brain and can be detected by a special camera in the PET scanner.

Electroencephalography (EEG): EEG is a procedure that allows measurement of physiological brain responses. Sensors placed on and around the head record small electrical currents produced by the brain.

Follow-up phone calls and appointments: participants will have follow-up phone calls every 3 months for 9 months following scan visits, and an in-person follow-up appointment 1 year after scans to assess mood and cognition, as well as document any changes. Follow-up assessments may continue for up to 5 years after the year one follow-up appointment.

Some subjects may be asked to return after the 1 year follow-up period to repeat study procedures to examine changes over time.

• Study Type: Observational
• Enrollment (Estimated): 100

Contacts and Locations

• Study Contact: Name: Nicole DellaGioia, MA; Phone Number: 203-737-6884; Email: nicole.dellagioia@yale.edu
• Study Contact Backup: Name: Sarah Boster, MA; Phone Number: 203-737-7066; Email: sarah.debonee@yale.edu

Study Locations

• United States
  • Connecticut
    • New Haven, Connecticut, United States, 06510
      • Recruiting
      • Yale Translational Brain Imaging Program
      • Contact: Sarah Boster, MA; Phone Number: 203-737-7066; Email: sarah.debonee@yale.edu
      • Contact: Nicole DellaGioia, MA; Phone Number: 2037376884; Email: nicole.dellagioia@yale.edu
      • Principal Investigator: Irina Esterlis, Ph.D.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Transdiagnostic sample of older individuals (age 55+ years) with stress disorders without psychosis including individuals with MDD, bipolar disorder, post-traumatic stress disorder (PTSD), dysthymia, and non-psychiatric individuals.

Description

Inclusion Criteria:

• able to give written informed consent
• age 55+
• English speaking

Exclusion Criteria:

• contraindication to MRI scanning including claustrophobia, high girth, moderate to significant white matter atrophy, and presence of ferromagnetic material in the body, including orthodontic braces or other non MR-compatible foreign bodies. All participants will be screened for metal objects by the same methods used for routine clinical MRI scanning
• for women: pregnancy or breastfeeding
• serious medical or neurological illness that in the opinion of the PI would interfere with the scientific goals of the study or participant safety
• pervasive developmental disorders (PDD) or primary psychotic disorders
• meet DSM-5 criteria for current severe substance use disorder (except marijuana or nicotine)
• head injury that led to significant long term decline in cognitive abilities as seen by decline in grades or work performance
• current psychosis, active significant suicidal (score of 6 on MADRS suicide item) or homicidal ideation
• lifetime history of neurologic abnormality including seizure disorder, cerebrovascular, or neoplastic lesion, neurodegenerative disorder, or significant head trauma resulting in post-traumatic amnesia >24 hours
• full scale IQ lower than 70
• contraindications to PET (e.g. poor venous access for placement of venous lines)
• history of prior radiation exposure for research purposes within the past year such that participation in this study would place them over FDA limits for annual radiation exposure. This guideline is an effective dose of 5 rem received per year
• history of a bleeding disorder or currently taking anticoagulants (such as Coumadin, Heparin, Pradaxa, Xarelto) *for subjects obtaining arterial line.
• blood donation within 8 weeks of the start of the study
• REM sleep disorder
• brain injury (TBI, seizure/epilepsy, stroke, TIA) in lifetime (self-report and medical chart review)
• electroconvulsive or ketamine therapy, or similar therapies that have rapid effects on brain neurochemistry within the past 6 months
• high risk for stroke (above first quartile on Framingham Stroke Risk Profile)
• current cancer

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Transdiagnostic; Participants will be a transdiagnostic sample of older individuals (age 55+ years) with stress disorders without psychosis including individuals with MDD, bipolar disorder, post-traumatic stress disorder (PTSD), dysthymia, and non-psychiatric individuals.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Social disconnection	Social disconnection composite measure determined by the following: Item #3 - Hamilton Depression Rating Scale (social withdrawal; range = 0-4) Item #12 - Beck Depression Inventory-II (loss of interest in people; range = 0-3) Item #14 - Center for Epidemiologic Studies Depression Scale (feelings of loneliness; range = 0-3) Item #2 - Snaith-Hamilton Pleasure Scale (enjoyment being with family or close friends; range = 0-1) Item #7 - Snaith-Hamilton Pleasure Scale (enjoyment seeing other people's smiling faces; range = 0-1) Item #17 - Profile of Mood States (loneliness; range = 0-4) Higher composite score = greater severity of social disconnection.	enrollment to end of study participation (approximately 1 year)
SV2A density	SV2A density as measured using [18F]SDM8 PET imaging.	enrollment to end of study participation (approximately 1 year)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite measure of suicide risk	Suicide risk will be operationalized as a composite score of death ideation, depressive symptoms, loss of personal and self-worth, executive control, and perceived meaning in life based on the following: Geriatric Suicide Ideation Scale (GSIS) suicide ideation subscale score (range 10-50, higher score indicates greater active suicidal ideation). GSIS death ideation subscale score (range 5-25, higher score indicates greater death ideation) Montgomery Asberg Depression Rating Scale (MADRS) total score (range 0-60, higher score indicates greater severity of depression) GSIS loss of personal and social worth subscale score (range 7-35, higher score indicates greater feeling of loss of personal and social worth) Cogstate Go/No-Go task score GSIS perceived meaning in life subscale score (range 8-40, higher score indicates lower perceived meaning in life)	enrollment to end of study participation (approximately 1 year)
Sex		enrollment to end of study participation (approximately 1 year)
Composite measure of suicide risk over time	identification of predominant trajectories of suicide risk measures (see 'composite measure of suicide risk' outcome measure) over 5 time points spanning the 12-month study period (0, 3, 6, 9, and 12 months).	12-month study period (from scanning to year 1 follow-up)

Collaborators and Investigators

• Sponsor: Yale University
• Investigators: Principal Investigator: Irina Esterlis, Ph.D., Yale University

Study record dates

Study Major Dates

• Study Start (Actual): May 8, 2023
• Primary Completion (Estimated): February 1, 2028
• Study Completion (Estimated): February 1, 2028

Study Registration Dates

• First Submitted: November 12, 2024
• First Submitted That Met QC Criteria: November 21, 2024
• First Posted (Actual): November 26, 2024

Study Record Updates

• Last Update Posted (Actual): June 8, 2026
• Last Update Submitted That Met QC Criteria: June 4, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: isolation; loneliness; social disconnection
• Other Study ID Numbers: 2000033973

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No