What Counts as an “Adequate” Antidepressant Trial?

Nearly every insurance decision about TMS or Spravato turns on one phrase: an inadequate response to two adequate antidepressant trials. Patients are often surprised to learn that medications they took for years may not count. An adequate trial generally means a therapeutic dose, taken consistently, for a long enough period, usually at least six weeks, with the outcome documented. A medication stopped after ten days because of side effects is a real experience, and it is usually recorded as a trial of intolerance rather than an adequate trial of efficacy.

On this page: What makes a trial adequate? · Dose · Duration · What usually does not count · Why this decides your coverage

What makes an antidepressant trial adequate?

Three things: the medication reached a therapeutic dose rather than a starting dose, it was continued long enough for a fair test, and the response was assessed and written down. Reviewers are reading a record, not a memory, so a trial that was adequate in real life but undocumented can still fail on paper.

How much medication counts as an adequate dose?

A therapeutic dose is one within the accepted effective range for that drug, not the low introductory dose used to limit early side effects. Many patients stay at a starting dose because it was tolerable, then conclude the medication did not work. Clinically and administratively, that is an incomplete trial rather than a failed one.

How long does a trial need to be?

Most criteria expect roughly six weeks at a therapeutic dose. Antidepressants generally take several weeks to show their full effect, which is why shorter exposures are not treated as a fair test. In the largest real-world treatment study, remission rates fell with each successive medication step, which is the evidence base behind the two-trial threshold used for advanced treatments (Rush et al, Am J Psychiatry 2006, PMID 17074942).

What usually does not count as an adequate trial?

Common examples: a medication stopped within days or a couple of weeks, a dose never increased past the starting point, a prescription filled but not taken consistently, a sample pack used briefly, or a medication taken years ago with no record available. None of these mean you did anything wrong. They simply do not satisfy the definition reviewers apply. Intolerance is still meaningful and should be documented, because most plans accept a documented inability to tolerate a medication as a separate pathway.

Why does this decide your coverage?

Because the two-adequate-trials standard is the gate for treatment-resistant depression, and TRD is the gate for TMS and Spravato coverage. Getting the history assembled properly is often the difference between approval and denial. That is why a first appointment for advanced treatment spends real time on medication history: names, doses, dates, and what happened. Our related guides cover how treatment-resistant depression is diagnosed, TMS prior authorization, and Spravato prior authorization. If you are unsure what your own history contains, an evaluation can reconstruct it with you, in Hayward or by telehealth across California.

This article is educational and is not legal or personalized medical advice. Never stop or change a medication without your own clinician. Reviewed by Nefretiri Abat, PMHNP-BC, JD.