# Participants and the trial lifecycle

This chapter follows a participant from sign-up to the end of the trial, and explains
the statuses you see in the overview.

## The participant journey

1. **Enrol**: the participant registers for the trial and is assigned a randomisation
   sequence (see {doc}`enrolment`). There is a short unlock delay before they can begin.
2. **Screening**: they complete the eligibility screening questionnaire. If they are
   not eligible, they do not proceed.
3. **Consent**: they read the participant information sheet and agree to the consent
   form. The version they agreed to is recorded.
4. **Baseline**: they complete the before-treatment questionnaires.
5. **Intervention and washout**: they move through the trial's phases: listening
   sessions during intervention periods, and rest during washouts (either no listening,
   or unmodulated listening, depending on the washout type).
6. **Post-trial / debrief**: after the last phase they complete the final
   questionnaire and can see their debrief.
7. **Completion**: submitting the final questionnaire completes the participant, which
   counts toward the trial's completion target.

## Statuses you will see

Registered / waiting to unlock
: Signed up, not yet started.

Active
: Currently taking part.

Completed
: Finished the trial. Counts toward the completion target.

Withdrawn
: Left the trial, or removed. Frees a recruitment place (see {doc}`enrolment`).

## Dropout

A participant who is inactive for longer than the trial's **inactivity dropout** window
(set in {doc}`setup/1-identity`) is treated as dropped out. Because the enrolment count
excludes withdrawn participants, a dropout also frees a recruitment place, which can let
a paused trial resume.

For what each of these stages looks like inside the app, see {doc}`participant-app`.