The problem with equal-step tapering
The traditional approach to reducing antidepressants involves cutting the dose by a fixed amount at regular intervals — for example, reducing from 20mg to 10mg to 0mg over several weeks. This seems logical: equal steps, equal time, predictable end point.
The problem is that this approach ignores how antidepressants actually work in the brain. The relationship between dose and effect is not linear — it is curved. Specifically, it follows what pharmacologists call a hyperbolic curve.
What this means is that a reduction from 20mg to 10mg has a very different effect on the brain than a reduction from 4mg to 2mg, even though both are a 50% reduction in dose. At lower doses, each milligram has a disproportionately large effect on the nervous system. Equal-step tapering gets exponentially harder as the dose gets lower — which is exactly why so many people sail through the first few reductions and then hit a wall at the end.
What hyperbolic tapering means
Hyperbolic tapering is a method of dose reduction that accounts for this curved relationship. Instead of reducing by a fixed amount each time, reductions are made as a proportion of the current dose — and that proportion gets smaller as the dose gets lower.
In practical terms, a hyperbolic taper for someone on 20mg sertraline might look something like this:
| Stage | Dose | Reduction from previous | Effect on brain receptors |
|---|---|---|---|
| Start | 20mg | — | Near-maximum receptor occupancy |
| Step 1 | 16mg | 4mg (20%) | Small change — receptors already saturated |
| Step 2 | 12mg | 4mg (25%) | Moderate change — receptors beginning to free up |
| Step 3 | 8mg | 4mg (33%) | More noticeable change at receptor level |
| Step 4 | 4mg | 4mg (50%) | Significant change — requires liquid preparation |
| Step 5 | 2mg | 2mg (50%) | Large neurological impact despite tiny dose |
| Step 6 | 1mg | 1mg (50%) | Every microgram matters at this level |
| Step 7 | 0mg | 1mg (100%) | Final step — smallest absolute change |
Notice that the absolute reductions get progressively smaller, even as the percentage reduction stays roughly constant. This is the essence of hyperbolic tapering — it tracks the brain's actual sensitivity to dose changes rather than following an arbitrary schedule.
The science behind it
The pharmacological basis for hyperbolic tapering comes from neuroimaging research showing how antidepressants bind to serotonin transporters in the brain. This work, particularly from researchers including Dr Mark Horowitz and Professor David Taylor, demonstrated that:
- At higher doses, serotonin transporters are near-maximally occupied — so large dose reductions produce relatively small changes in receptor occupancy
- At lower doses, the same absolute reduction produces a much larger proportional change in receptor occupancy
- The relationship between dose and receptor occupancy follows a hyperbolic (curved) function — hence the name
- This explains why standard linear tapers become increasingly difficult as lower doses are reached
This research formed the basis of the updated NICE guidelines on depression (NG222) and the NICE guideline on medicines associated with dependence (NG215), both of which now recommend proportional rather than linear dose reductions.
Key points about hyperbolic tapering
- Reductions are made as a proportion of the current dose — not a fixed amount
- The absolute dose reduction gets smaller as the total dose gets lower
- This mirrors how the brain actually responds to dose changes at the receptor level
- Now recommended by NICE guidelines on depression and medication dependence
- Liquid formulations are usually necessary to achieve precise low-dose reductions
- The total duration of a hyperbolic taper is typically longer than a linear taper — but the experience is more manageable
Why liquid formulations are necessary
Standard antidepressant tablets come in a limited range of doses — sertraline, for example, is available as 50mg and 100mg tablets. Once the taper reaches doses below the smallest available tablet, it becomes impossible to continue reducing accurately without a different formulation.
Liquid preparations allow very precise dosing — for example, sertraline oral solution at 20mg/ml can be measured to the nearest 0.1ml, giving doses as small as 2mg. This level of precision is essential for the lower stages of a hyperbolic taper.
In the UK, liquid preparations of most common antidepressants are available on prescription. We routinely issue private prescriptions for liquid formulations as part of our deprescribing support.
Who benefits from hyperbolic tapering
Hyperbolic tapering is relevant for anyone reducing a long-term antidepressant, but it is particularly important for:
- People who have been on medication for more than a year — the longer the use, the more important careful low-dose management becomes
- People who have had a difficult experience with standard tapering — in most cases, this reflects the method rather than the individual
- People on medications with short half-lives, such as venlafaxine or paroxetine — where the nervous system responds quickly to dose changes
- People who are highly sensitive to dose changes and notice withdrawal symptoms quickly after each reduction
For GPs and prescribers
Hyperbolic tapering is now supported by NICE NG222 and NG215, as well as the Maudsley Deprescribing Guidelines (2024). The key practical implication is that liquid formulations should be considered proactively rather than as a last resort. We are happy to liaise with GPs regarding shared care arrangements for patients undergoing structured deprescribing, and can issue private prescriptions for liquid antidepressant preparations throughout the taper.
Our approach
How we apply hyperbolic tapering in practice
Every deprescribing plan we build is based on hyperbolic principles — proportional reductions, response-led pacing, and appropriate formulation management throughout. We advise on liquid preparations, monitor progress at each stage, and adjust the plan based on how each person responds.
We are proud to work in clinical collaboration with Dr Mark Horowitz — one of the researchers who developed the evidence base for hyperbolic tapering and co-author of both the landmark 2019 Lancet Psychiatry paper and the Maudsley Deprescribing Guidelines (2024). Dr Horowitz sees patients on our deprescribing pathway as an affiliate specialist psychiatrist.
If you have tried to reduce an antidepressant before and found it very difficult, a structured hyperbolic approach is almost certainly what was missing.
Book an Initial ConsultationReferences
- 1. Horowitz MA, Taylor D. Tapering of SSRI treatment to mitigate withdrawal symptoms. Lancet Psychiatry. 2019;6(6):538–546. DOI: 10.1016/S2215-0366(19)30032-X
- 2. Horowitz MA, Taylor D. The Maudsley Deprescribing Guidelines: Antidepressants, Benzodiazepines, Gabapentinoids and Z-drugs. Wiley-Blackwell; 2024. ISBN: 978-1119822981
- 3. National Institute for Health and Care Excellence. Depression in adults: treatment and management. NICE guideline NG222. London: NICE; 2022.
- 4. National Institute for Health and Care Excellence. Medicines associated with dependence or withdrawal symptoms: safe prescribing and withdrawal management for adults. NICE guideline NG215. London: NICE; 2022.
- 5. Royal College of Psychiatrists. Stopping antidepressants. 2020. Available at: rcpsych.ac.uk
Related reading
Hyperbolic tapering is not a fringe idea — it is now the evidence-based standard for reducing antidepressants safely.
The reason so many people find standard tapers difficult is not personal weakness. It is that the method they were given did not account for how the brain actually responds to dose changes.