Long-Term Antidepressant Use: What the Evidence Shows

Long-term antidepressant use — beyond the first year — is increasingly common. The Royal College of Psychiatrists and major Cochrane reviews describe the evidence base as good for the first twelve to twenty-four months but more limited for very long-term use. Knowing what is established and what is uncertain helps you have a clearer conversation with your prescriber.

What is established

Continued antidepressant treatment beyond initial response reduces relapse risk. Cochrane reviews of maintenance trials show meaningfully lower relapse rates over twelve to twenty-four months for patients who continue treatment versus those who stop. This is the evidence base that informs the standard NICE recommendation of continued treatment for at least six to twelve months after remission.

What is less certain

Beyond twenty-four months, evidence becomes more limited. Long-term safety data exists for most antidepressants over decades of use, but high-quality randomised trials at very long durations are fewer. Discussions of long-term effects — cognitive, metabolic, cardiovascular — continue in the clinical literature. The Royal College of Psychiatrists describes long-term use as appropriate for many patients but a topic for ongoing review.

What to discuss with your prescriber

Why you are continuing. Relapse risk, persistent symptoms, or a clear benefit you want to maintain — your prescriber should know your reasoning.

Whether the dose is still right. Dose needs can shift across life stages, and a review is an opportunity to check whether the current dose is still appropriate.

New health changes. Any new health conditions or medications since your last review may affect the medication choice going forward.

A planned trial off the medication. Long-term continuation should be a deliberate choice, not a default. Discuss whether a supervised taper is appropriate.

Bringing a written summary to your review appointment makes the conversation more productive and ensures nothing is missed.

What to flag to your prescriber

Raise these at any review

New health conditions that may interact with your antidepressant.
New medications that may interact.
Side effects that have emerged or worsened over time.
A desire to plan a trial off the medication.

Frequently asked questions

How long is it safe to take antidepressants?

Long-term safety data exists for most antidepressants over decades of use. Continuation should be reviewed periodically with your prescriber based on your individual circumstances — the question is not just safety, but whether continued treatment is the right choice for you at this point.

Do antidepressants stop working over time?

Some patients experience reduced effectiveness over time — a phenomenon sometimes called tachyphylaxis. It is not universal but is documented in the clinical literature. Discuss with your prescriber if you suspect this is happening.

Should I take a break if I have been on an antidepressant for years?

Discuss with your prescriber. Planned trials off the medication are sometimes appropriate but should be supervised and gradual. Stopping without guidance risks discontinuation symptoms and, for some patients, relapse.

Evidence and sources referenced

NICE Guideline NG222 — Depression in adults: treatment and management (United Kingdom).
Royal Australian and New Zealand College of Psychiatrists (RANZCP) — Clinical Practice Guidelines for Mood Disorders.
NPS MedicineWise — prescriber and patient resources on antidepressant treatment (Australia).
Royal College of Psychiatrists — patient information on antidepressants.
TGA and FDA — product information for SSRI and SNRI medication classes.
Maudsley Prescribing Guidelines in Psychiatry — prescribing patterns and side-effect timelines.