Partial Response to AntidepressantsWhen Better Isn’t Well

After weeks of depression, feeling somewhat better can be a huge relief. Sleep improves, the worst days are fewer, and you can function again. But many people on an antidepressant reach a point where they’re better, not well: still tired, still flat, still struggling to concentrate or enjoy things. That’s a partial response to antidepressants, and it’s worth taking seriously. This guide explains the difference between response and remission, what research shows, and what can be done when progress stalls.

The goal of depression treatment is remission, meaning minimal or no symptoms and a return to functioning, not just an improvement.

Remission vs Response

The difference between remission vs response is that response usually means symptoms have dropped by at least half, while remission means symptoms are minimal or gone. Someone can respond to treatment and still have significant symptoms left over, called residual symptoms.

This distinction matters for the future. In the STAR*D trial, as summarized in an American Journal of Psychiatry editorial, relapse rates among people who reached remission were 33.5%, 47.4%, 42.9%, and 50.0% after treatment steps one through four, while relapse rates were higher, 59% to 83%, among those who improved but didn’t reach remission.

STAR*D Results: What the Largest Real-World Study Showed

STAR*D results show that remission is often reached in steps: in this large NIMH-funded study, remission rates were 36.8%, 30.6%, 13.7%, and 13.0% for the first, second, third, and fourth treatment steps, with an overall cumulative remission rate reported as 67%. Remission became harder to reach after two failed steps.

The 67% figure has been debated. A 2023 reanalysis argued the cumulative rate was lower, and the original authors responded in the American Journal of Psychiatry that the reanalysis excluded hundreds of participants. What both sides agree on is that many people need more than one treatment step to reach remission.

Measurement makes the difference between response and remission visible. Rating scales at each visit show whether symptoms are still dropping or have plateaued, which is often the signal to change the plan rather than wait longer.

Feeling 50% better can feel like a win after a long depression. It's also a reason to keep going.

Residual Depression Symptoms

Residual depression symptoms are the symptoms that remain after partial improvement, most often fatigue, low energy, poor concentration, sleep problems, low motivation, and reduced pleasure. They can make it hard to work, connect with others, and feel like yourself, and they’re linked to higher relapse risk.

• Fatigue: tired even when mood is better.
• Concentration: brain fog or slowed thinking.
• Sleep: lingering insomnia or oversleeping.
• Motivation: difficulty starting tasks.
• Pleasure: activities still feel flat.

Our guides to depression brain fog and anhedonia explain two common residual symptoms.

Why Partial Response Happens

Partial response can happen because the dose is too low, the treatment hasn’t had enough time, the medication isn’t the right fit, another condition such as anxiety, ADHD, sleep apnea, or substance use is contributing, or ongoing stress is maintaining symptoms. Sometimes the diagnosis itself needs another look.

Timing matters too. Many antidepressants need several weeks at an adequate dose before their full effect is clear, so judging too early can lead to unnecessary changes, while waiting too long can prolong suffering.

A careful review often reveals a specific target. Our guides to sleep apnea and depression and when an antidepressant stops working cover related causes.

It’s also common for people to adapt to a partial response without noticing. After a long depression, feeling somewhat better can seem like the new normal. Asking “Is this how I felt before depression?” can help clarify whether there’s more ground to recover.

Next Steps When Depression Improves Only Partly

Next steps when depression improves only partly usually include optimizing the dose, allowing enough time, switching to a different antidepressant, adding a second medication, adding psychotherapy, and addressing sleep, activity, and co-occurring conditions. Measuring symptoms at each visit helps show whether changes are working.

1. Measure where you are. Use a rating scale to quantify remaining symptoms.
2. Check dose and time. Confirm the dose is adequate and the trial long enough.
3. Look for contributors. Screen for sleep, anxiety, substances, and medical issues.
4. Choose one change. Dose adjustment, switch, add-on, or therapy.
5. Reassess. Track progress toward remission at each visit.

Combining therapy with medication can add benefit. Our guides to therapy vs medication and treatment-resistant depression explain the options when two or more treatments haven’t led to remission.

When to Talk With Your Psychiatrist

Talk with your psychiatrist if you’ve been on an antidepressant for several weeks at an adequate dose and still have noticeable symptoms, or if improvement has stalled. Don’t settle for partial relief if full remission is possible, and don’t change doses on your own.

A comprehensive medication review can identify what’s holding progress back. Our guide to the PHQ-9 explains how symptom scores guide decisions. If you’re having thoughts of suicide, call or text 988 in the US.

Bring a short list of the symptoms that remain and how they affect your day. Specifics make it easier to target the next step.