Using tadalafil to enhance antidepressant effects in patients with major depression

The Phosphodiesterase Inhibitor Tadalafil as an Adjunct to Antidepressants in Major Depressive Disorder Patients: Randomized, Double-Blind, Placebo-Controlled Trial

Phase1; Phase2 Interventional Sadat City University · NCT05030623

This study is testing if adding tadalafil, a medication usually for erectile dysfunction, can help improve mood in adults with major depression.

Quick facts

PhasePhase1; Phase2
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years to 50 Years
SexAll
SponsorSadat City University Academic / other
Locations1 site (Shibīn Al Kawm, Menoufia)
Trial IDNCT05030623 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates the use of tadalafil, a phosphodiesterase inhibitor, as an adjunct treatment for patients diagnosed with Major Depressive Disorder (MDD). The study aims to explore tadalafil's potential antidepressant-like effects by modulating neuroplasticity-related pathways in the brain, particularly in areas associated with mood regulation. Participants will receive either tadalafil or a placebo while being monitored for changes in depressive symptoms. The trial includes adult outpatients who meet specific diagnostic criteria and have been off psychotropic medications for a designated period.

Who should consider this trial

Good fit: Ideal candidates are adults diagnosed with Major Depressive Disorder who are not currently on psychotropic medications.

Not a fit: Patients with bipolar disorder, personality disorders, or those with a history of substance abuse may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a novel adjunctive option for patients with major depression, potentially improving their overall treatment outcomes.

How similar studies have performed: While the use of tadalafil for erectile dysfunction has shown benefits, its application as an adjunct treatment for depression is relatively novel and has not been extensively tested in similar studies.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Eighty adult outpatients with the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) diagnosis of MDD based on a MINI Neuropsychiatric Interview (MINI) (American Psychiatric Association., 2000; Sheehan et al., 1998), without psychotic features and a total 17 item HAM-D score of at least 18 with item 1 (depressed mood) scored 2 or greater were eligible (Hamilton, 1960).

Patients were requested to be free of all the psychotropic and anti-inflammatory medications for at least 4 weeks before participating in the study.

Exclusion Criteria:

Patients with bipolar I or bipolar II disorder Patients with personality disorders Patients with eating disorders Patients with substance dependence or abuse Patients with concurrent active medical condition Patients with history of seizures Patients with history of receiving Electroconvulsive therapy (ECT) Patients with inflammatory disorders Patients with allergy or contraindications to the used medications Patients with finally pregnant or lactating females Cardiovascular disorders Severe renal impairment: creatinine clearance of ≤ 25 ml/min Moderate or severe hepatic impairment

Where this trial is running

Shibīn Al Kawm, Menoufia

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Major Depressive Disorder
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.