A Phase 1/2 interventional study of Fluoxetine - immediate treatment and Fluoxetine - delayed treatment in Obsessive-Compulsive Disorder, sponsored by Yale University. Recruiting at 1 site in United States. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-22.
Sponsored by Yale University · Phase 1/2, Interventional, and Basic science
The proposed randomized, double-blind research study will use functional magnetic resonance neuroimaging using state-of-the-art HCP acquisition protocols and analytic pipelines, to identify predictors and correlates of response to an accepted first-line pharmacological treatment for obsessive-compulsive disorder.
The proposed study intends to recruit 2 groups:
Hypothesis-driven analyses and exploratory analyses will be performed in parallel.
This study will address the following Specific Aims:
635 studies on the registry are indexed under Obsessive-Compulsive Disorder; 166 are open to participants now.
This study's planned enrollment of 100 is above the median of 45 across 520 interventional studies indexed under Obsessive-Compulsive Disorder.
Browse Obsessive-Compulsive Disorder studies →Yale University is the lead sponsor of 1,770 studies on the registry; 294 are open to participants now.
Of its 221 completed or terminated interventional studies of FDA-regulated products, 129 (58%) have results posted.
Counted across the registry records on this site, refreshed daily.
Inclusion Criteria:
(ii) signed , approved by the Yale Human Investigations Committee; and (iii) ability and willingness to participate in all study procedures, including clinical assessments and fMRI scans.
OCD Participants:
(i) a DSM diagnosis of OCD, established as detailed above; (ii) a baseline Y-BOCS of ≥16; (iii) no current psychoactive medication, with the exception of the occasional use of a PRN medication for sleep; (iv) treatment seeking, and clinically appropriate for fluoxetine pharmacotherapy; (v) for women of , not pregnant or intending to become pregnant, and willing to use reliable over the course of the study, either prescribed contraceptive (oral contraceptive, injectable, or implant) or one barrier method (e.g. diaphragm with spermicide, intrauterine device, cervical cap). Women of childbearing potential must have a negative serum pregnancy test at screening and negative urine pregnancy tests at the study baseline and on each scan day appointment prior to the MRI scan.
Healthy Control Participants:
(i) no current DSM diagnosis (by clinician interview confirmed by SCID or MINI); (ii) no documented or clinically suspected family history in a first- or second- degree relative of OCD, Tourette syndrome, hoarding disorder, body dysmorphic disorder, or a compulsive grooming disorder.
Exclusion Criteria:
Exclusion criteria for all groups will include:
(i) any unstable medical, psychiatric, or neurological condition (including active or otherwise problematic suicidality) that may necessitate urgent treatment; (ii) any substance use disorder within the past 6 months; (iii) use of psychotropic medications within the past 8 weeks, with the exception of occasional use of a sleep aid or analgesic; (iv) use of an as-needed sleep aid or prescription analgesic within 3 days of the scan; (v) any history of a primary psychotic disorder or of mania; (vi) any evidence of substance use on urine toxicology testing; (vii) any major neurological disease or history of major head trauma, including concussion with extended loss of consciousness; (viii) pregnancy; (ix) any metal in the body or other to MRI scanning; (x) severe claustrophobia, back pain, or other condition that may make an extended MR scan difficult or lead to excessive movement during the scan.
OCD Participants:
(i) past allergy or adverse reaction to fluoxetine or another SSRI, or other clinical contraindication to fluoxetine pharmacotherapy; (ii) documented nonresponse to a past trial of fluoxetine of appropriate dose (≥40 mg/dy) and duration (≥12 weeks).
(iii) Patients taking Coumadin or Monoamine oxidase inhibitors (MAOIs) will be excluded from the study.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The healthy control group will be an age matched sample of unmedicated healthy adults who will be recruited and imaged once at baseline and the data compared with that of OCD subjects at baseline.
The OCD group will comprise of unmedicated individuals with clinically significant OCD symptoms. OCD Subjects will be randomized, double-blind, to receive immediate or delayed (by 6 weeks as a placebo lead-in) pharmacotherapy.
Drug: Fluoxetine - immediate treatment · Drug: Fluoxetine - delayed treatment
Following the Baseline assessment, OCD subjects will be randomized to receive either immediate fluoxetine monotherapy or delayed fluoxetine, after a 6-week placebo lead-in.
Also known as: fluoxetine, prozac
Following the Baseline assessment, OCD subjects will be randomized to receive either immediate fluoxetine monotherapy or delayed fluoxetine, after a 6-week placebo lead-in.
Also known as: fluoxetine, prozac
Obsessive-compulsive severity change
Yale-Brown Obsessive-Compulsive Scale (Y-BOCS);72,73 -This is a checklist and Clinician administered - 10 item severity scale, from none to extreme. Total severity score range is 0 to 40. This will be presented as % improvement in Y-BOCS as a continuous measure of treatment response, rather than an artificially dichotomized measure of 'response', in all analyses. This the primary outcome measure of change across the study treatment and scans.
Time frame: 18 weeks
Tic severity change
Yale Global Tic Severity Scale (YGTSS) will be used to measure Tic severity. It is a clinician administered instrument with a score from 0 to 25- 25 being the most severe.
Time frame: 18 weeks
Beck Depression Inventory-II
Beck Depression Inventory-II (BDI-II);82 21 items to assess intensity of depression.
Time frame: 18 weeks
Anxiety
Beck Anxiety Inventory (BAI);83 21 item self report on a 4 point Likert scale - 0 (not at all) to 3 (severely).
Time frame: 18 weeks
Obsessive-compulsive concerns
Dimensional Obsessive-Compulsive Scale (DOCS);84 20 questions, asks about 4 categories of obsessive-compulsive concerns (each consists of 5 items scored on a Likert scale of 0-no symptoms to 4 - extreme symptoms) over the previous month.
Time frame: 18 weeks
Magical ideation
Magical Ideation Scale (MIS);86 30 item true / false scale, assessing erroneous beliefs based on magical thinking.
Time frame: 18 weeks
Sensory phenomena
University of São Paulo Sensory Phenomena Scale (USP-SPS);87
Time frame: 18 weeks
"Not Just Right" experiences and sensations in OCD
Not Just Right Experiences Questionnaire Revised (INC).88 19 Questions: Rate 10 NJR Experiences; Choose most recent one; Identify how long ago it occurred; then complete 7 dimensional ratings of that NJRE: frequency, intensity, immediate distress, delayed distress, rumination, urge to respond, and responsibility to do something about the NJRE, from 1 (absence) to 7 (extreme level /or within the past day).
Time frame: 18 weeks
Plan to share: No
No publications or documents are linked to this record.
Started Oct 2019 (actual). Primary completion is estimated for Sep 2027, 95 months after the start.
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Obsessive-Compulsive Disorder →