How it is measured
Short, repeatable tasks, not a reconstruction of personal history. The person performs tasks; the instruments record.
The principle
The profile emerges from tests of function, not from what a person remembers or states about themselves. Of the clinical record we keep only what is needed to read the signals correctly: medication, recent exposures, medical conditions.
Clinical assessment remains, but outside the model: it serves as an independent external comparison, not as an ingredient.
Why studying people already in treatment helps
In a structured treatment setting, time since last use is known and verifiable. There is at last a certain time zero, and life has already supplied the perturbation.
Each person becomes their own control: the same person is measured at different times, rather than different people compared with each other. For the first gate, within-person repeatability, that is enough.
It stops being enough the moment one wants to say what is abnormal. Defining a reference range — what is typical, what falls outside it — requires comparison groups: exposed people who have not lost control, and low-exposure controls. Both are included in the cross-sectional study.
One distinction must hold, though: a control group supplies the reference range, it says nothing about vulnerability. That requires observing people beforehand, not comparing them afterwards. Phase two deals with it.
The tasks
| Function | Task | Quantity measured |
|---|---|---|
| Price of relief | Choice between waiting, effort and forgoing | Price curve as a function of hours since last use |
| Response and recovery | Repeated stimuli at varying intervals | Amplitude, latency, persistence of response |
| Stopping an action | Start a response and halt it on cue | Estimated stop time, errors |
| Updating a choice | Which action brings reward changes mid-task | Trials needed to adapt |
| Physiological recovery | Standardised challenge and return | Dynamics of heart, breath, pupil, skin conductance |
Sleep in the preceding 48 hours enters as a measured condition, not as a test: the question is whether, within the same person, a documented change in sleep alters performance and the capacity to return.
The two gates, in order
- Repeatability. Is the curve stable within the same person weeks apart? If not, everything stops here. Many computerised tasks produce precise numbers that are unstable from one day to the next: this is documented, and must be confronted at the start rather than at the end.
- Added value. Do the parameters anticipate outcome at three and six months better than the information already available?
No hypothesis about mechanism is tested before the first gate is passed.
The tracks
Three parallel tracks, the same protocol, started in sequence rather than together.
- Track A — alcohol. First, for a practical reason: a blood marker exists that documents consumption over the preceding weeks without having to ask. The outcome is verifiable.
- Tracks B and C — other substances. The choice is open. Substitution treatment offers documented timing and adherence but the medication masks part of the dynamics; other substances offer a cleaner picture but outcomes that are harder to verify. This is one of the decisions belonging to the scientific team.
What is needed and missing
This is a study on people in treatment. It requires a clinical centre, an ethics committee, and a principal investigator with access to the population. It is not a part that can be built from outside.