What clinicians need to know about screening patients for psychedelic services

Last reviewed: August 2026 · Psychedelic law changes quickly — verify current status before relying on this page.

For licensed healthcare professionals whose patients are considering or have accessed Oregon’s psilocybin program, and who want to understand what clinical screening involves, what the formal exclusions are, and where a prescribing clinician’s role is most valuable.

The short answer

Oregon’s psilocybin program has three formal exclusion criteria — lithium use within 30 days, current ideation of harm to self or others, and history of diagnosis or treatment for active psychosis. These are the only conditions under which a facilitator may not proceed with a client. Many conditions and medications that clinical trials typically screen out are not formal exclusions in Oregon. Facilitators conduct a medication and health history review using OPS’s standardized client information form, but they cannot perform clinical assessment, diagnose conditions, or advise on medication management. This creates a specific and valuable role for the prescribing clinician: reviewing the patient’s medication list before access, advising on washout timing for high-risk medications, and being available for clinical support afterward.

Oregon’s three formal exclusions

OAR 333-333-5050 establishes three absolute contraindications. A facilitator who encounters any of these on the client information form may not proceed with the administration session, regardless of individual circumstances.

Lithium use within 30 days is a hard stop. The combination of psilocybin and lithium is associated with an increased risk of seizures and delirium based on case reports and pharmacological analysis. The 30-day washout reflects the time needed for lithium clearance. A patient on lithium who is considering psilocybin services should not self-discontinue — abrupt lithium cessation carries its own risks including rebound mania, and any discontinuation should be managed by the prescribing clinician.

Current ideation of harm to self or others is the second exclusion. A client who endorses this on the screening form may not receive services. This reflects the risk of intensified or destabilizing psychological experience in someone already in acute suicidal or homicidal ideation.

History of diagnosis or treatment for active psychosis at any time is the third exclusion. This covers any prior episode of active psychosis that was diagnosed or treated, regardless of current stability. It does not exclude everyone with a complex psychiatric history — a patient with a history of depression, anxiety, PTSD, or bipolar disorder without a psychosis component is not excluded on this basis.

The clinician’s screening role

Facilitators are trained to use the client information form but are not permitted to provide clinical assessment or advise on medication management. A prescribing clinician reviewing a patient’s situation before psilocybin access is providing something the facilitation model cannot: clinical judgment about medication interactions, individual risk factors, and preparation needs that go beyond the three formal exclusions.

The most relevant clinical questions a prescribing clinician should address: Is the patient on lithium? Is the patient on an MAOI? Is the patient on an SSRI or SNRI, and what does attenuation mean for their goals? Does the patient have cardiovascular disease, poorly controlled hypertension, or a cardiac arrhythmia that warrants specific assessment? Is the patient pregnant or breastfeeding?

MAOIs

Monoamine oxidase inhibitors — phenelzine, tranylcypromine, isocarboxazid, selegiline — are a strong practical contraindication even though Oregon does not formally exclude MAOI users. MAO-A inhibition reduces psilocin breakdown (psilocybin’s active metabolite), potentially potentiating and prolonging the experience, and carries theoretical serotonin syndrome risk and hemodynamic effects including hypertensive emergency and hyperthermia. Standard clinical practice in psilocybin research requires a two-week washout of MAOIs before administration. A patient on an MAOI should discuss a tapering plan with their prescribing clinician well in advance of any planned session.

SSRIs and SNRIs

SSRIs and SNRIs do not pose a documented safety hazard in combination with psilocybin — ten studies evaluating concomitant use reported no cases of serotonin syndrome or significant serotonin toxicity. However, they substantially attenuate psilocybin’s subjective effects. Prolonged SSRI use downregulates 5-HT2A receptors, psilocybin’s primary target, and the dampening effect may persist for three to six months following discontinuation.

For a patient on an SSRI for depression who hopes to access psilocybin services, this creates a practical decision. Discontinuing the SSRI to restore responsiveness carries risks — withdrawal symptoms, potential depressive relapse — that need to be weighed against the benefit of a more responsive experience. Exploratory data from COMPASS Pathways’ Phase 2 study showed some antidepressant signal in TRD patients who remained on SSRIs despite reduced subjective effects, suggesting meaningful benefit may still be achievable. The prescribing clinician is the appropriate person to help the patient navigate this decision. Facilitators cannot.

Anticonvulsant mood stabilizers

Valproate, carbamazepine, and lamotrigine may attenuate psilocybin’s effects through serotonergic mechanisms. Unlike lithium, these carry no documented seizure risk in combination with psilocybin and are not formally excluded in Oregon’s program. A clinician should discuss the likely attenuation realistically with the patient so they have accurate expectations going into the session.

Antipsychotics

Typical and atypical antipsychotics may blunt psilocybin’s effects through 5-HT2A receptor antagonism. A patient taking an antipsychotic for a psychotic condition will typically meet the formal exclusion for history of active psychosis diagnosis or treatment — the formal exclusion and the pharmacological concern often coincide. A patient taking a low-dose atypical antipsychotic for a non-psychotic indication without any history of psychosis is in a different clinical position and warrants individual assessment.

Cardiovascular considerations

Psilocybin produces modest transient increases in heart rate and blood pressure during the active experience. Clinical trials have typically excluded patients with significant cardiovascular disease, arrhythmias, or poorly controlled hypertension. Oregon’s program has no formal cardiovascular exclusions. A prescribing clinician is well positioned to assess whether a specific patient’s cardiac status creates meaningful concern that the patient should address before proceeding.

Pregnancy and breastfeeding

Oregon’s informed consent document includes acknowledgments regarding pregnancy and facilitators ask about it on the client information form. Psilocybin has not been studied in pregnant or breastfeeding individuals, and the risk-benefit calculus is generally unfavorable. Oregon does not formally exclude pregnant clients, but the informed consent process is designed to surface the question. A clinician whose patient is pregnant or breastfeeding and considering psilocybin access can provide clinical guidance the facilitation model cannot.

Cannabis

Cannabis may intensify anxiety or paranoia during a psilocybin session. A clinician can reasonably advise patients who regularly use cannabis to consider abstaining in the period around their session, particularly on the day itself.

What the clinician’s involvement looks like practically

A prescribing clinician whose patient is planning to access Oregon’s psilocybin program can provide meaningful clinical value by reviewing the medication list, advising on any washouts or modifications needed, providing realistic expectations about how current medications may affect the experience, and offering to be available for clinical support in the integration period afterward. This does not require a formal referral role — the patient contacts the service center independently — but it is a clinically important contribution that the facilitation model alone cannot replicate.

A clinician who engages in this review and documents their reasoning is both helping the patient and establishing a record that they exercised appropriate clinical judgment in their advisory role.

When public information may be enough

OAR 333-333-5050 sets out Oregon’s formal screening requirements. The client information form and informed consent document are published at oregon.gov/psilocybin. Current peer-reviewed literature on psilocybin pharmacological interactions is available through PubMed — a clinician’s guide to psilocybin interactions published in Psychiatric Times in 2025 provides a useful clinical summary.

When you should speak with a lawyer

This article addresses clinical screening questions. For questions about the legal scope of clinicians’ interactions with psilocybin services — including HB 2387’s discussion protection, dual licensure, and practice structure — see other articles in this section of the library.

You might also want to read

• Can physicians discuss or recommend psilocybin services to patients?
• Dual licensure: what HB 2387 changed for Oregon clinician-facilitators
• Psychedelic-assisted therapy and the standard of care
• Prescribing, referring, and recommending: where the legal lines are for clinicians
• What to tell patients who ask about psychedelic treatment options