Clinical TrialMajor Depressive Disorder (MDD)PsilocybinPsilocybinRecruiting

Cancer Related Major Depression Treated With a Single Dose of Psilocybin (CAPSI)

Randomised, quadruple‑blind, active‑placebo controlled Phase II trial (n=100) comparing a single 25 mg oral dose of psilocybin to 1 mg in patients with cancer‑related MDD (age 20–80).

Target Enrollment
100 participants
Study Type
Phase II interventional
Design
Randomized, quadruple Blind

Detailed Description

This randomised, parallel‑group, quadruple‑blind study randomises participants 2:1 to a single oral 25 mg dose of psilocybin or an active placebo (1 mg) to evaluate antidepressant efficacy in cancer‑related major depressive disorder.

Primary outcome is change in depressive symptoms; participants undergo preparatory and follow‑up sessions, safety monitoring including ECG and labs, and must abstain from other psychotherapies or antidepressants during the study period.

Study Arms & Interventions

Psilocybin 25 mg

experimental

Single oral 25 mg psilocybin dose

Interventions

  • Psilocybin25 mg
    via Oral• single dose• 1 doses total

Psilocybin 1 mg

active comparator

Active placebo 1 mg psilocybin

Interventions

  • Psilocybin1 mg
    via Oral• single dose• 1 doses total

    Randomisation 2:1 (25 mg : 1 mg)

Participants

Ages
20 – 80
Sexes
Male & Female

Inclusion Criteria

  • Inclusion Criteria
  • Signed informed consent via minavårdkontakter.se
  • Are 20 to 80 (inclusive) years old at the time of signed informed consent
  • Are able to read, speak, and understand Swedish
  • Are able and willing to adhere to study requirements, including attending all study visits, preparatory and follow-up sessions, and completing all study evaluations
  • Are able to swallow capsules
  • Women of childbearing potential (WOCBP) must agree to practice an effective means of birth control throughout the duration of exposure to the Investigational Product, from Screening through Day 8.
  • A diagnosis of a malignant neoplasm with ICD-10 code C00–C97
  • ≥1 month after cancer diagnosis and ≥12 months of life expectancy at time of inclusion
  • Physical functioning performance status 0–2 (WHO/ECOG)
  • Meet ICD-10 criteria for major depressive disorder and are currently experiencing a major depressive episode of at least 30 days
  • Screening PHQ-9 total score ≥10
  • Willing to abstain from other psychotherapeutic or antidepressant treatments during the study period (180 days; washout 5 half-lives)
  • Have an identified support person
  • Agree to be driven/accompanied home following dosing

Exclusion Criteria

  • Exclusion Criteria
  • Last contact with health care due to cancer monitoring or treatment >1 year ago
  • Women who are pregnant, intend to become pregnant during the study, or are currently nursing
  • Unwilling or unable to discontinue formal psychotherapy
  • Ongoing antidepressant drug treatment (no interruption will be done by study personnel)
  • Previously during the current episode received DBS or VNS
  • Currently receiving ECT or TMS
  • Unable or unwilling to discontinue medications that are UDP or UGT enzyme modulators (eg valproate); prohibited agents must be stopped at least 5× elimination half-life plus one week prior to Baseline
  • Report lifetime use of psychedelic substances (psilocybin, LSD, mescaline, DMT, ayahuasca, 5-MeO-DMT, ibogaine, MDMA, or other psychedelics)
  • Cancer involving the CNS
  • Cancer treatment/follow-up incompatible with protocol
  • Significant cardiovascular conditions (congenital long QT, disabling coronary artery disease, cardiac hypertrophy, ischemia, congestive heart failure, significant ECG abnormalities, artificial heart valve, or other clinically significant cardiac history)
  • Elevated BP at Screening SBP >150 mmHg or DBP >95 mmHg on three readings, or at Baseline SBP >160 mmHg or DBP >100 mmHg on three readings
  • History of stroke or TIA
  • Moderate to severe hepatic impairment (Child-Pugh ≥7)
  • Uncontrolled epilepsy
  • Insulin-dependent diabetes or history of hypoglycaemia requiring medical intervention
  • Inability or unwillingness to suspend sildenafil/tadalafil ≥72 hours prior to dosing
  • Positive urine drug test for listed substances (exceptions for prescribed stable benzodiazepines); cannabis use excluded
  • Prescription methadone or buprenorphine naloxone users excluded; prescription opiates must be stopped at least 5× elimination half-life prior to inclusion
  • Nicotine dependence that disallows nicotine-free period during dosing
  • Meet ICD-10 criteria for schizophrenia spectrum or other psychotic disorders, bipolar I or II, or antisocial personality disorder
  • Moderate or severe alcohol or drug use disorder within the past 12 months
  • Any psychiatric condition or symptom judged by PI to be a more significant clinical problem than MDD
  • First-degree relative with schizophrenia spectrum or other psychotic disorders
  • Psychiatric condition judged incompatible with rapport or safe exposure to psilocybin
  • Suicidal ideation or behaviour meeting exclusion thresholds (see suicidalityDetails)
  • Allergy or intolerance to materials in either drug product
  • Hepatitis B, C or uncontrolled HIV
  • One or more clinically relevant pathological blood test results (as determined by study physician; except CRP)

Primary Results(1 publication)

Participants

N = 100S. et al. 2026 →

Adverse Events (from all publications)

Arm / GroupnAny TEAESevereSeriousDiscont.
Psilocybin 25 mgexperimental67————
Psilocybin 1 mgactive_comparator33————

* The paper describes the CAPSI trial design (2:1 randomization, total N=100) but does not provide the safety results for the participants in this specific manuscript, which focuses on the facilitator training evaluation.

Study Details

Locations

region Västra Götaland — Gothenburg, Sweden
Örebro sjukhus — Örebro, Sweden
Norra Stockholms Psykiatri — Stockholm, Sweden
Psykiatriska Kliniken, Akademiska Sjukhuset — Uppsala, Sweden

Related Publications

Evaluation of a facilitator training program in a randomized controlled trial of psilocybin treatment for depression

Published
Authors
Morel, N. S., Stenbaek, D. S., Lundberg, J., Beckman, M.

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