Treatment-resistant depression: what it means and what can help

You’ve tried antidepressants. Perhaps more than once. Perhaps several different ones, at different doses, over months or years. And yet here you are, still struggling. Still not feeling like yourself.

If this sounds familiar, you may be living with treatment-resistant depression. There is a clinical explanation for it, and there are evidence-based next steps. This guide explains what treatment-resistant depression means, why it happens, and what the evidence says about the options available in the UK.

You are not treatment-resistant as a person. You simply haven’t yet found the treatment that works for you.

What is treatment-resistant depression?

Treatment-resistant depression, often shortened to TRD, is usually defined as depression that has not responded adequately to at least two different antidepressants, each taken at an appropriate dose for an adequate length of time (typically six to eight weeks or more).

It is more common than many people realise. In the STAR*D study, one of the largest real-world antidepressant studies ever conducted, only around 30% of patients reached remission on their first antidepressant. The chances of remission fell with each further medication step, and around a third of participants had still not reached remission after four treatment steps.

This is not a reflection of personal weakness, lack of effort or character. For a significant proportion of people, medication alone does not adequately address what is driving their symptoms.

Why do antidepressants not work for everyone?

Depression is not one single condition. It is a broad clinical category that can arise from different neurological, genetic, hormonal and environmental causes. Antidepressants are designed to address one aspect of this, the balance of neurotransmitters like serotonin and noradrenaline, but in some people the main driver of depression lies elsewhere.

Differences in brain activity

Brain imaging research has found reduced activity in specific regions in many people with depression, particularly the dorsolateral prefrontal cortex (DLPFC), which is involved in mood regulation, decision-making and emotional processing. For some people, this pattern may not respond fully to medication alone.

How your body processes medication

Some people carry genetic variations that affect how their liver metabolises antidepressants. Standard doses can then produce much higher or lower levels in the blood than intended, which helps explain why a medication that works well for one person does little for another. Some people also find a medication becomes less effective over time.

Inadequate dosing or duration

In some cases, previous treatment courses have been too short or at too low a dose. While this is different from true treatment resistance, it produces the same outcome for the patient: no improvement, and mounting frustration.

Whatever the cause, if two or more antidepressants have not brought adequate relief, it is often the right time to review your treatment plan with a psychiatrist and consider other approaches.

The emotional reality of treatment-resistant depression

Beyond the clinical definition, treatment-resistant depression carries a particular emotional weight. People who have been through several medication trials often describe a growing sense of hopelessness, not just about their depression, but about the possibility of ever feeling better.

“I’ve tried everything. Nothing works. Maybe nothing ever will.” This is one of the most common things we hear when people first contact us, and in our experience it is rarely the end of the road.

Many patients have spent years in the NHS system, seeing their GP, trying different medications and attending NHS Talking Therapies (formerly IAPT). They have been told to wait. They have been referred and re-referred. They have struggled through side effects that made them feel worse, not better: weight gain, emotional numbness, reduced libido, fatigue.

If this is your experience, we want to be direct with you: having tried several antidepressants without success does not mean your depression cannot be treated. It means a different treatment strategy may be needed. That is a meaningful and important distinction.

What are the evidence-based options for treatment-resistant depression?

Several approaches have an evidence base for treatment-resistant depression. The right one depends on your history and preferences, and should be discussed with a psychiatrist. Options include:

• Augmentation strategies: adding lithium, an atypical antipsychotic or another medicine to an existing antidepressant. Effective for some people, but it requires close monitoring and has its own side effects.
• Electroconvulsive therapy (ECT): highly effective for severe depression, but it requires a general anaesthetic, with its associated risks, and can cause temporary memory problems.
• Ketamine and esketamine: newer approaches that can act quickly, but with limited availability in the UK, significant cost, and ongoing questions about long-term use.
• Repetitive transcranial magnetic stimulation (rTMS): covered by NICE guidance (IPG542) since 2015, which found no major safety concerns and adequate evidence of short-term effectiveness for depression, although responses vary. It is non-invasive, needs no anaesthetic, is not associated with memory problems, and can usually be given alongside existing medication. Learn more about rTMS for depression.

For many people, rTMS offers a practical balance: a good safety profile, a solid evidence base, and few practical barriers to treatment.

How rTMS works for treatment-resistant depression

Antidepressants work by altering brain chemistry throughout the body. rTMS works differently: it uses targeted magnetic pulses to stimulate the dorsolateral prefrontal cortex, the area often underactive in depression. This is thought to help restore activity and connectivity in the brain circuits involved in mood regulation.

Because it works in a different way from antidepressants, rTMS can help some people who have not responded to medication. It is not a stronger version of the same thing; it is a different approach altogether. You can read what happens during rTMS treatment, step by step.

Our consultant psychiatrists, Dr Nikhila Deshpande and Dr Babu Nayar, published an outcomes study in the Journal of Psychiatry Depression & Anxiety in 2020. Across patients treated at our clinic between February 2018 and December 2019, including people with treatment-resistant depression, the study recorded a response rate of 66.66% and a remission rate of 37.03%.

66.66% response rate (published study, 2018–19)

37.03% remission rate (published study, 2018–19)

Response usually means symptoms have reduced by at least half; remission means symptoms have reduced to a minimal level. Our more recent clinical audits show a similar picture, with 66–76% of patients responding. These figures come from routine clinical practice rather than a controlled trial, and results vary from person to person. rTMS does not work for everyone, but many people who had lost hope do respond.

What to do if you think you have treatment-resistant depression

If you have tried two or more antidepressants without adequate improvement, or if depression is significantly affecting your ability to work, maintain relationships or enjoy life, it is worth discussing rTMS as a next step. Please don’t stop or change any medication without speaking to your doctor first.

You do not need a GP referral to contact us. We offer a free 20-minute telephone call with one of our Senior Consultant Psychiatrists, who will answer your questions and let you know whether rTMS is likely to be suitable for you. If it is, the next step is a full psychiatric assessment.

Assessment appointments are typically available within one to two weeks, and treatment can begin shortly after. You can find details of fees, payment options and insurance on our website.

If you are in crisis or having thoughts of harming yourself, please don’t wait for an appointment. Call 999, contact NHS 111 (choose the mental health option), or call Samaritans free on 116 123, day or night.

Frequently asked questions about treatment-resistant depression

This article was written by the Tranquil TMS team. Tranquil TMS is a CQC-registered clinic in Cheadle, led by Senior Consultant Psychiatrists Dr Nikhila Deshpande and Dr Babu Nayar.