Week 6 on an Antidepressant: The Decision Point

Week six is the standard decision point in major clinical guidelines. NICE NG222 and RANZCP Mood Disorders Guidelines both recommend a clinical review at six to eight weeks if there has been no meaningful improvement — to consider dose adjustment, switching antidepressants, or augmentation. Knowing the standard timeline helps you have the right conversation at the right time.

What week six should look like for responders

For patients who will respond to the medication, week six typically shows the first measurable mood changes: less reactivity, quieter background anxiety, more capacity for things that had felt impossible. The changes are usually subtle in week six and continue to develop over the following weeks. People around you may notice before you do.

What week six looks like for partial or non-responders

Some patients show partial response by week six — some improvement but not full. Others show no meaningful change. Cochrane reviews of antidepressant efficacy describe a substantial proportion of patients requiring dose adjustment or medication change to reach full response. Lack of response at week six is not a personal failure; it is the standard reason guidelines recommend review at this point.

What happens at the review

Dose increase. Often the first step for partial responders — many people require a higher dose than the starting one to reach full therapeutic effect.

Switching to a different antidepressant. Often recommended for non-responders. A lack of response to one SSRI or SNRI does not predict a lack of response to another.

Augmentation with a second medication. Specialist territory, but a recognised and guideline-supported strategy when initial monotherapy is insufficient.

Adding therapy. Combining medication with psychological therapy is a strong evidence-based approach recommended in NICE NG222 and RANZCP guidelines.

Your prescriber will assess what fits your specific situation. The discussion is most productive if you bring written notes covering the last six weeks.

What to flag to your prescriber

Raise these at your week-six review or sooner

No meaningful improvement in mood or function by week six.
Side effects that are still significant by week six.
Worsening rather than improvement in mood.
New or worsening suicidal thoughts — raise this at any point, do not wait for the review.

Frequently asked questions

What happens if my antidepressant has not worked by week six?

Major guidelines recommend a clinical review at this point to consider dose adjustment, switching, or augmentation. Lack of response is a recognised reason for next-step planning — not a reason to conclude that treatment cannot work for you.

Could it still start working after week six?

Yes — some patients respond at week eight or even later. Six weeks is the decision point for review, not necessarily the end of the trial period. Your prescriber will factor in any partial response or trajectory of change when advising on next steps.

Should I stop the medication if it has not worked by week six?

Talk to your prescriber rather than stopping independently. Stopping abruptly can produce discontinuation symptoms; a planned next step — whether continuing, switching, or augmenting — is safer and more effective than a self-directed stop.

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.