"Doctor, I've been through three different antidepressants, thirty sessions of rTMS, even Esketamine. Nothing really sticks." I hear some version of this almost every week. And each time, I do the same thing: I ask the patient to walk me through their entire history, paying close attention to the periods when they felt better.
More often than you might expect, those "better" stretches conceal an episode of hypomania that was never recognised. The patient remembers feeling sharp, productive, social. They assumed the clouds had simply lifted. What they didn't realise is that they were looking at the other face of a mood disorder. Studies estimate that 21 to 26 percent of people initially diagnosed with depression are later reclassified as having bipolar disorder[1][2]. That reclassification explains why so many of them spent years stuck in so-called treatment-resistant depression.
This article covers what bipolar disorder actually is, why it gets mistaken for unipolar depression so frequently, which warning signs to watch for, how to screen yourself, and why the treatment that works is not another antidepressant but a mood stabiliser. If you or someone close to you has been cycling through medications with little to show for it, consider this a chance to step back and re-examine the diagnosis.
Why multiple antidepressants may not be working
Treatment-resistant depression (TRD) is formally defined as failure to achieve remission after at least two adequate antidepressant trials, each at a sufficient dose for six to eight weeks using medications with different mechanisms of action. Once someone reaches this point, the clinical priority should shift from "which antidepressant next?" to "is the diagnosis correct in the first place?"
I have seen this pattern countless times. A 30-year-old software engineer who has been through SSRIs, SNRIs, mirtazapine augmentation, rTMS, and Esketamine, with results that oscillate between partial improvement and relapse. When I ask him to describe the best period of his adult life, he recalls a month in university when he slept four hours a night and felt unstoppable, coding at peak efficiency, talking non-stop. He thought he had finally recovered. Nobody told him that might have been hypomania.
The core issue is straightforward: antidepressants are effective for unipolar depression, but they perform poorly against bipolar depression and can even trigger a manic or hypomanic switch[3]. If the depression you are trying to treat is actually part of a bipolar cycle, antidepressants alone will never resolve it.
What bipolar disorder is, and the one feature that separates it from depression
Bipolar disorder (formerly called manic-depressive illness) is a psychiatric condition defined by cyclical, large-amplitude mood swings. A person's emotional state alternates between manic or hypomanic highs and depressive lows, often with stretches of relative stability in between. The single feature that distinguishes it from unipolar (major) depression is this: bipolar disorder includes episodes of mania or hypomania; unipolar depression does not.
The table below offers a quick comparison.
Table 1. Bipolar disorder vs. unipolar depression
| Feature | Bipolar Disorder | Unipolar Depression |
|---|---|---|
| Mood trajectory | Oscillates between highs and lows | Low or neutral only |
| Elevated episodes | Abnormal energy, reduced sleep need, euphoria | None |
| Antidepressant monotherapy | Poor response; may trigger mania | Usually effective |
| First-line treatment | Mood stabilisers (lithium, lamotrigine, etc.) | SSRI / SNRI antidepressants |
| Typical age of onset | 18 to 25 years | 25 to 35 years |
| Lifetime prevalence | Approximately 2 to 4% (types I + II combined)[4] | Approximately 16 to 20%[5] |
Bipolar I vs. bipolar II
Bipolar I features full-blown mania: days of little to no sleep, reckless spending or investing, pressured speech, grandiose beliefs, sometimes frank psychosis. Family and friends almost always notice. The person is usually brought to medical attention, sometimes involuntarily.
Bipolar II involves only hypomania, a milder elevation. The person feels sharper, sleeps less (five hours and feels great), bursts with creative energy and social confidence. If these symptoms last at least four days and represent a clear departure from baseline, the clinical threshold for hypomania is met. Because the person is functioning well, or even better than usual, most bipolar II patients interpret hypomania as "feeling like myself again" and never mention it to a clinician[2].
Why bipolar II is the most commonly misdiagnosed
This is arguably the most important concept in this entire article. People with bipolar II almost always present to a doctor during a depressive episode, because nobody seeks help when they feel on top of the world. The clinician sees textbook depression, hears nothing about hypomania, and the working diagnosis becomes major depressive disorder.
The trouble deepens from there. Bipolar II depression tends to be:
- More stubborn than typical unipolar depression, with a weaker response to antidepressants
- More prone to frequent recurrence
- Associated with a suicide attempt rate at least as high as bipolar I, and higher than unipolar depression[6]
When this kind of patient keeps getting more antidepressants piled on, the medications not only fail to help but may provoke mixed states or rapid cycling, pushing the clinical picture further off track.
Key symptoms: looking beyond depression to the "up" side
Everyone recognises the depressive pole. What most people miss is the manic or hypomanic pole, because it often feels like a welcome return to health rather than a symptom. The table below lays out the core features of each phase side by side.
Table 2. Symptom comparison across mood phases
| Domain | Depressive phase | Manic / hypomanic phase | Clinical significance |
|---|---|---|---|
| Mood | Persistent sadness, emptiness, hopelessness | Unusually elevated, expansive, or irritable | High |
| Sleep | Insomnia or hypersomnia | Sleeps 3 to 4 hours without fatigue | High |
| Energy | Exhaustion, loss of motivation | Boundless energy, cannot sit still | Moderate |
| Thought speed | Slowed thinking, poor concentration | Racing thoughts, ideas cascading | Moderate |
| Speech | Quiet, slow | Pressured, rapid, hard for others to interject | Moderate |
| Behaviour | Withdrawal, social avoidance | Impulsive spending, hypersexuality, excessive socialising | High |
| Self-perception | Worthlessness, guilt | Inflated self-esteem, grandiosity | High |
One critical point: a person in hypomania feels fantastic and does not believe anything is wrong. Relying on self-report alone is therefore unreliable. Family and close friends are often more accurate observers. If you are accompanying a loved one to a psychiatric appointment, mention whether you have ever seen them go through a stretch where they were noticeably different: unusually high-energy, sleeping very little, talking more than usual, taking uncharacteristic risks. That single observation can change the trajectory of treatment.
Self-screening: the Mood Disorder Questionnaire (simplified)
Below is a condensed seven-item version adapted from the internationally validated Mood Disorder Questionnaire (MDQ)[7]. Think back across your entire life and ask whether there was ever a distinct period when the following applied:
MDQ simplified self-screen (7 items)
| # | Question | Yes / No |
|---|---|---|
| 1 | You felt so different from your usual self that others might have noticed a clear change in your behaviour | ☐ Yes ☐ No |
| 2 | Your mood was unusually elevated or euphoric, well beyond your normal range | ☐ Yes ☐ No |
| 3 | Your self-confidence surged and you felt you could accomplish anything | ☐ Yes ☐ No |
| 4 | You slept only 3 to 4 hours a night without feeling tired the next day | ☐ Yes ☐ No |
| 5 | Your thoughts raced so fast you could barely keep up | ☐ Yes ☐ No |
| 6 | You had far more energy than usual and felt a physical need to stay constantly active | ☐ Yes ☐ No |
| 7 | You did things you would not normally do that could have got you into trouble (impulsive spending, risky sexual behaviour, reckless driving, etc.) | ☐ Yes ☐ No |
How to interpret your answers (for self-reference only, not a clinical diagnosis):
- 4 or more "Yes" answers, especially if these experiences clustered within the same time period and affected your work, relationships, or daily functioning: a formal bipolar evaluation with a psychiatrist is strongly recommended
- 2 to 3 "Yes" answers: this may reflect personality traits or isolated situational responses, but it is still worth raising with your doctor at your next visit
- 0 to 1 "Yes" answers: no clear indication of bipolar features at present
Important disclaimer: This simplified checklist is a screening aid, not a diagnostic instrument. The full MDQ includes additional questions about co-occurrence and functional impact. A definitive diagnosis requires a psychiatrist to apply DSM-5 criteria[8], review a detailed history, and ideally obtain collateral information from someone who knows you well. Rather than telling your doctor "I tested positive for bipolar," describe the specific periods you endorsed. That narrative is far more useful clinically.
Three structural reasons bipolar disorder keeps getting missed
When antidepressant after antidepressant fails, the explanation is not always "the drug is too weak" or "the dose needs to go higher." More often, the diagnosis was off from the start. Three recurring patterns drive the misdiagnosis.
Patients with bipolar II only seek help during depression. Hypomania feels good. Nobody books a psychiatric appointment during the best week of their year. The result is that clinicians see a depressed person, hear nothing about elevated episodes, and reasonably (but incorrectly) diagnose unipolar depression. Data suggest that from first mood episode to correct bipolar II diagnosis, the average delay is 8 to 10 years[2]. Throughout those years, patients receive treatment aimed at the wrong condition.
Patients do not report hypomania because they do not recognise it as abnormal. Even when a clinician asks, "Have you ever had a period of unusually elevated mood?" many patients say no. They filed the experience under "I finally felt like myself for a while." A more productive question is: "Tell me about the period in your life when you had the most energy, needed the least sleep, and were at your most productive or sociable." Framed that way, the answer often reveals a textbook hypomanic episode.
Antidepressants themselves can trigger a manic switch. Giving antidepressant monotherapy to a bipolar patient may induce mania, mixed states, or rapid cycling[3][9]. When this happens, the resulting agitation or emotional instability is sometimes misread as an antidepressant side effect or worsening anxiety, prompting yet another antidepressant switch rather than a diagnostic re-evaluation.
Layer these three factors together and you get the classic "treatment-resistant depression" trajectory. The most productive next step is not a new antidepressant. It is a fresh look at the diagnosis.
How bipolar disorder is treated: mood stabilisers vs. antidepressants
The cornerstone of bipolar treatment is not an antidepressant but a mood stabiliser. This is the single biggest therapeutic difference from unipolar depression. The table below summarises the most commonly used options.
Table 3. Pharmacological options for bipolar disorder
| Drug class | Representative agent | Indication | Key considerations |
|---|---|---|---|
| Classic mood stabiliser | Lithium | Bipolar I and II; first choice when suicide risk is present | Requires periodic blood-level monitoring; thyroid and kidney function checks |
| Anticonvulsant mood stabiliser | Lamotrigine | Maintenance against bipolar depression | Must titrate slowly to avoid Stevens-Johnson syndrome |
| Anticonvulsant mood stabiliser | Valproate (Depakine) | Acute mania; mixed episodes | Significant teratogenic risk; use with great caution in women of childbearing age |
| Atypical antipsychotic | Quetiapine, olanzapine, aripiprazole | Acute mania or severe bipolar depression | Monitor weight and metabolic parameters |
| Antidepressant (use with caution) | SSRI / SNRI | Stubborn bipolar depression, only with mood-stabiliser cover | Never use as monotherapy; risk of manic switch or mixed states |
Lithium remains the gold-standard first-line agent in international guidelines[10]. It is one of very few medications proven to reduce suicide risk in bipolar disorder. More than half a century of clinical data supports its efficacy. The trade-off is a narrow therapeutic window: blood levels that are too high become toxic, so regular blood draws are essential, along with vigilance about dehydration and abrupt discontinuation.
Lamotrigine is the go-to choice for preventing depressive relapses in bipolar disorder. It is weight-neutral and generally well tolerated, but the starting dose must be increased gradually over several weeks to minimise the rare but serious risk of Stevens-Johnson syndrome.
Valproate works well for acute mania and mixed states. However, its high teratogenic risk means it is generally avoided in women who could become pregnant, or used only with a rigorous contraception plan in place.
In my own practice, when a patient with "treatment-resistant depression" is re-evaluated and found to have bipolar disorder, the first move is usually not to abruptly stop the antidepressant. Instead, I introduce a mood stabiliser as the foundation, wait for the mood to settle, then reassess whether the antidepressant should continue, be tapered, or be removed entirely. Getting the direction right matters far more than adjusting the dose.
For patients who cannot take medication (for example, during breastfeeding or due to drug sensitivities), or whose response to pharmacotherapy is limited, repetitive transcranial magnetic stimulation (rTMS) is a viable option for bipolar depression[10], particularly when layered on top of a mood-stabiliser regimen.
Frequently asked questions
Q1: How can I tell whether I have depression or bipolar disorder?
It comes down to one question: has there ever been a period in your life when your mood was distinctly elevated, you needed significantly less sleep without feeling tired, your confidence spiked, and you talked so much that others struggled to get a word in, lasting at least four days? If the answer is yes, a comprehensive bipolar assessment with a psychiatrist is in order. A depressive episode alone, however severe, is not enough information for even a specialist to distinguish unipolar from bipolar depression.
Q2: Why haven't multiple antidepressants worked for me?
Three common reasons: (1) the actual diagnosis may be bipolar disorder rather than unipolar depression; (2) co-occurring conditions like anxiety, trauma, or personality issues have not been adequately addressed; (3) non-pharmacological approaches such as psychotherapy and lifestyle modification have been neglected. After two failed antidepressant trials, the next step should be a diagnostic re-evaluation, not another antidepressant.
Q3: Can antidepressants trigger mania?
In someone with bipolar disorder, yes. In purely unipolar depression, the risk is very low. The catch is that many bipolar patients are initially misdiagnosed as unipolar, which means this risk is systematically underestimated. The International Society for Bipolar Disorders (ISBD) advises against antidepressant monotherapy in bipolar disorder[9]. Antidepressants should only be considered under the protective umbrella of a mood stabiliser.
Q4: Can bipolar disorder be cured?
Bipolar disorder is a chronic illness. Current medical evidence does not support the idea of a permanent cure. What the evidence does support is that long-term mood-stabiliser therapy allows most patients to maintain extended periods of stability, hold jobs, maintain relationships, and raise families. The essentials are early and accurate diagnosis, consistent medication, regular follow-up, sufficient sleep, and avoidance of drugs and alcohol. Think of it the way you would think of managing blood pressure or blood sugar: a condition that responds well to sustained, structured care.
Q5: I scored positive on the MDQ. Does that mean I have bipolar disorder?
Not necessarily. The MDQ is a screen, not a diagnostic tool. A positive result means you deserve a formal evaluation, but the final diagnosis must come from a psychiatrist applying DSM-5 criteria, reviewing your full history, and ideally speaking with a family member or close friend. In clinical practice, about 60 to 70 percent of MDQ-positive individuals go on to receive a confirmed bipolar diagnosis. The remainder may have anxiety disorders, post-traumatic stress, personality-related conditions, or mixed affective features.
Q6: A family member refuses to accept that they might have bipolar disorder. What can I do?
This is common, especially during hypomania, when the person feels better than they have in months. Some practical strategies: frame the appointment as a check-up for mood instability rather than invoking the term "bipolar disorder"; go with them instead of asking them to go alone; consult the psychiatrist on your own first as a concerned family member, and let the clinician advise on next steps. If you observe clear impulsive spending, sexual risk-taking, or self-harm, that is a signal to seek immediate professional help.
Further reading:
Dr. Tam's perspective
As a practising psychiatrist, I want to say this directly to anyone reading: if you have tried multiple antidepressants, perhaps rTMS or ECT as well, and your depression keeps returning, that is not a personal failure. It does not mean you are not trying hard enough. It may mean the diagnostic lens needs to be refocused.
A few concrete steps you can take:
- Write down, as specifically as you can, the period of your life when you had the most energy, the best mood, and the least need for sleep. Bring that description to your next appointment.
- If a family member or partner can attend with you, ask them to think about whether they have ever seen you go through a stretch where you seemed markedly different. Their perspective is often more diagnostically useful than your own recall.
- A positive MDQ result does not equal a diagnosis, but it is worth scheduling a thorough evaluation.
- If the diagnosis shifts from unipolar to bipolar, the treatment strategy changes substantially: antidepressants become a supporting player at best, mood stabilisers take centre stage, and adjunctive rTMS remains a valid tool.
- Bipolar II carries a suicide risk at least as high as bipolar I. Hypomania is not recovery. It is the other face of the illness.
Many bipolar patients wait 8 to 10 years before receiving the correct diagnosis. For most of that time, they are treated for a condition they do not have. Every year the diagnosis is corrected sooner is a year saved from heading in the wrong direction.
Want to book an appointment with Dr. Tam?
Psychiatrist at Ten-Chan & Ten-Hsiang General Hospital, Zhongli. Consultations in English, Mandarin and Cantonese.
Book AppointmentReferences
- Hirschfeld RM, Lewis L, Vornik LA. Perceptions and impact of bipolar disorder: how far have we really come? Results of the National Depressive and Manic-Depressive Association 2000 survey of individuals with bipolar disorder. J Clin Psychiatry. 2003;64(2):161-174. DOI · PubMed
- Hirschfeld RM. Differential diagnosis of bipolar disorder and major depressive disorder. J Affect Disord. 2014;169(Suppl 1):S12-S16. DOI · PubMed
- Pacchiarotti I, Bond DJ, Baldessarini RJ, et al. The International Society for Bipolar Disorders (ISBD) task force report on antidepressant use in bipolar disorders. Am J Psychiatry. 2013;170(11):1249-1262. DOI · PubMed
- Merikangas KR, Akiskal HS, Angst J, et al. Lifetime and 12-month prevalence of bipolar spectrum disorder in the National Comorbidity Survey replication. Arch Gen Psychiatry. 2007;64(5):543-552. DOI · PubMed
- Kessler RC, Berglund P, Demler O, et al. The epidemiology of major depressive disorder: results from the National Comorbidity Survey Replication (NCS-R). JAMA. 2003;289(23):3095-3105. DOI · PubMed
- Novick DM, Swartz HA, Frank E. Suicide attempts in bipolar I and bipolar II disorder: a review and meta-analysis of the evidence. Bipolar Disord. 2010;12(1):1-9. DOI · PubMed
- Hirschfeld RM, Williams JBW, Spitzer RL, et al. Development and validation of a screening instrument for bipolar spectrum disorder: the Mood Disorder Questionnaire. Am J Psychiatry. 2000;157(11):1873-1875. DOI · PubMed
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR). Washington, DC: American Psychiatric Publishing; 2022.
- Yatham LN, Kennedy SH, Parikh SV, et al. Canadian Network for Mood and Anxiety Treatments (CANMAT) and International Society for Bipolar Disorders (ISBD) 2018 guidelines for the management of patients with bipolar disorder. Bipolar Disord. 2018;20(2):97-170. DOI · PubMed
- Goodwin GM, Haddad PM, Ferrier IN, et al. Evidence-based guidelines for treating bipolar disorder: revised third edition recommendations from the British Association for Psychopharmacology. J Psychopharmacol. 2016;30(6):495-553. DOI · PubMed