Treatment resistant depression refers to depression that has been unsuccessfully treated with at least two antidepressants.

Importantly, treatment resistant depression is not depression without a cure, and several alternative and emerging treatments exist that may be helpful.

At GoodMind Therapeutics, we provide professional care for your mental health journey, including nurse administered therapy which may be helpful for those experiencing treatment resistant depression.

While many people with depression are successfully treated with antidepressants, a growing range of approaches is being explored by practices like GoodMind, guided by safety, ethics, and a deep respect for the people we support.

In the following article, we’ll look at what defines treatment resistant depression, what to do when depression doesn’t respond to antidepressants, and what your options are for alternative treatments when antidepressants are not working.

What is treatment resistant depression?

Treatment resistant depression may be diagnosed when the following criteria are met :

• A patient has an existing diagnosis of a major depressive disorder (MDD)
• A patient has experienced the failure of at least two different first line antidepressants (often SSRIs, selective serotonin reuptake inhibitors, or SNRIs, serotonin and norepinephrine reuptake inhibitors) taken at the adequate dosage and duration (usually 6-8 weeks) to treat symptoms

Approximately 30% of people with MDD have treatment resistant depression.

Why antidepressants may not work

The failure of antidepressants can be for many reasons, most of which are still being studied.

Biologically, depression is a complex condition involving more than just one chemical imbalance in the brain, and not all people’s nervous systems respond to changes in serotonin or other neurotransmitters in the same way.

Some people have subtle differences in brain chemistry, receptor activity, or neural connectivity that make a given antidepressant less effective for them.

When SNRIs or SSRIs are not working anymore, this can also be caused by co‑existing physical health problems (like thyroid or metabolic issues), stress, sleep disruption, substance use (including alcohol), or other mental health conditions such as anxiety or bipolar disorder.

These can mask or maintain depressive symptoms even when a medication is being taken as prescribed.

In some cases people develop tolerance to a medication over time — sometimes referred to as tachyphylaxis — where it seems initially helpful but then stops having the same effect.

This phenomenon is especially observed with long‑term use of certain antidepressants.

How long should antidepressants take to work?

Most antidepressants take about 4–8 weeks at a therapeutic dose before full benefit is expected.

If core symptoms like persistent low mood, ongoing hopelessness or loss of interest haven’t noticeably improved in 4-8 weeks, it may suggest the current medication isn’t working as hoped.

Signs your antidepressant is not effective

• Symptoms remain at similar severity or get worse : If depressive symptoms such as fatigue, sleep problems, low motivation, or appetite changes are the same or more intense than before starting medication, rather than trending toward improvement, this can be a sign the treatment isn’t effective for you.· Partial response that stalls: Some people experience small improvements in sleep or energy but still struggle significantly with mood, motivation or daily functioning. This “partial response” indicates the antidepressant may not be fully addressing your depression.
• Emotional blunting or numbness : Feeling persistently emotionally “flat” may be an indicator that the medication’s effect doesn’t match your symptom profile or goals for recovery.
• Persistent or intolerable side effects outweigh perceived benefits : While some side effects can be expected early on, if issues like chronic fatigue, restlessness, sexual side effects or other physical symptoms persist beyond the typical adjustment phase and reduce quality of life, it may signal the need to reassess treatment.
• Return of previous depression symptoms after initial improvement : In some cases, antidepressants may seem to work at first but then stop being effective over time, a phenomenon sometimes called “tachyphylaxis” — especially reported with commonly prescribed SSRIs.
• Functional impact persists despite medication : If ongoing depression continues to interfere with your ability to work, socialise, complete daily tasks or enjoy relationships, despite proper medication use for an adequate period, this can be a clinical sign to review your treatment plan.

Advanced treatment options for treatment resistant depression

As mentioned, treatment resistant depression is not incurable depression, and many emerging and established treatments exist to improve the lives of those with MDD that does not respond to antidepressants.

Some of these treatments include :

• Transcranial Magnetic Stimulation (TMS) : This is a non‑invasive brain stimulation therapy that uses magnetic pulses to activate areas of the brain involved in mood regulation. It’s often used when multiple antidepressants haven’t worked and can be effective without the need for anaesthesia or surgery. Many people with TRD experience symptom improvement with repeated sessions over several weeks.
• Esketamine (Spravato®) Nasal Spray : Esketamine is a newer medication derived from ketamine that works differently from traditional antidepressants by targeting glutamate pathways in the brain. It’s administered under medical supervision and is approved for people who haven’t responded to at least two antidepressant trials. This treatment can act more rapidly than standard medications.
• Intravenous Ketamine Infusions : Similar to esketamine but delivered intravenously in a clinic, ketamine can produce rapid relief of depressive symptoms in some people within hours to days. It’s usually given as a series of infusions and is used when conventional treatments have been ineffective.
• Electroconvulsive Therapy (ECT) : ECT is a long‑established neuromodulation treatment where controlled electrical currents are passed through the brain under anaesthesia to trigger brief seizures. It can be highly effective for severe or refractory depression, especially when rapid response is needed or other treatments have failed.
• Deep Brain Stimulation (DBS) : Although less widely available and still largely in clinical trial settings, DBS involves surgically implanting electrodes in specific brain regions to help regulate mood‑related circuits. It’s usually considered only for very severe, chronic cases when other treatments have been unsuccessful.
• Augmentation or Combination Pharmacotherapy : This means adding another medication (such as lithium, certain antipsychotics, or other agents) to an existing antidepressant to enhance response. These strategies are often tried before or alongside more invasive options, with evidence supporting benefit in some people.

When to speak to a mental health professional

If you have severe depression that is not improving with medication, you may benefit from an alternative approach.

You should speak to your mental health professional or GP if you feel that your symptoms are not improving.

Even if antidepressants have been ineffective, there are still a range of treatment options available.

GoodMind Therapeutic’s nurse administered therapy is generally designed for :

• Adults experiencing ongoing mental health symptoms or chronic conditions, particularly those who may not have benefited from previous approaches.
• Individuals seeking additional clinical support or alternative care pathways.

To confirm eligibility, you can start by filling out the screening form. Requirements may vary depending on the program.

Many patients contact us simply to explore whether treatment is right for them.

You’re welcome to reach out even if you’re just looking for information.