What Is Bipolar Disorder?
Bipolar disorder is a psychiatric condition characterised by mood episodes that alternate between "highs" (mania or hypomania) and "lows" (depression). During manic episodes, a person may feel extraordinarily energetic, need far less sleep, have racing thoughts, exhibit inflated self-confidence, and make impulsive financial or personal decisions. Depressive episodes present with symptoms virtually identical to major depressive disorder[1].
Large-scale epidemiological studies estimate the lifetime prevalence of bipolar I and II at 1% to 2%, rising to 4% to 5% when subthreshold presentations are included[2]. The condition affects men and women in roughly equal numbers, although women are more likely to present with bipolar II (hypomania plus major depression) and are more often misdiagnosed with unipolar depression. On average, the gap between first symptom onset and correct diagnosis is 6 to 10 years[3].
In my clinic, many patients with bipolar disorder arrive saying, "I've tried so many antidepressants and none of them work." The problem is not that they are treatment-resistant; it is that they have been treated for the wrong diagnosis all along. Once the direction shifts to bipolar disorder and the correct class of medication is introduced, improvement often comes faster than anyone expected.
The DSM-5 distinguishes two main subtypes[1]:
- Bipolar I: At least one full manic episode (lasting at least 7 days, or severe enough to require hospitalisation), with or without major depressive episodes
- Bipolar II: At least one hypomanic episode (lasting at least 4 days, with functioning still largely intact) plus at least one major depressive episode. Bipolar II is not a "milder form" of the illness; the depressive burden and functional impairment are often greater
Causes and Brain Mechanisms
Bipolar disorder arises from the interplay of genetic, neurobiological, and environmental factors. It has one of the highest heritability estimates among psychiatric conditions, with twin studies placing it at approximately 60% to 85%[4].
Neurotransmitter Changes
Four major neurotransmitter systems are implicated:
- Dopamine: During mania, dopaminergic activity is abnormally elevated, driving euphoria, impulsivity, and excessive goal-directed behaviour. During depression, activity drops, leading to anhedonia and lack of motivation[5]
- Serotonin: Markedly deficient during depressive episodes, linked to low mood and suicidal ideation
- Glutamate: The brain's principal excitatory neurotransmitter. Abnormal glutamate concentrations have been found in the prefrontal cortex and hippocampus of people with bipolar disorder, potentially contributing to mood instability and cognitive difficulties[6]
- GABA: The brain's main inhibitory neurotransmitter. Reduced GABA function may disrupt the excitatory-inhibitory balance, making mood more prone to swing to either extreme
Brain Structural and Functional Changes
Key neurobiological findings in bipolar disorder
| Brain Region | Normal Function | Changes in Bipolar Disorder |
|---|---|---|
| Prefrontal Cortex | Impulse control, emotion regulation, planning | Reduced grey matter volume and activity, leading to poor impulse control and difficulty regulating emotions[7] |
| Amygdala | Emotional response, threat detection | Hyperactive and often enlarged, with exaggerated responses to emotional stimuli |
| Striatum | Reward processing, motivational drive | Overactivated reward circuitry during mania, driving impulsive behaviour and excessive goal pursuit |
Genetic and Environmental Factors
Having a first-degree relative with bipolar disorder increases your risk 7 to 10 fold[4]. Yet genetics only sets the stage. Environmental triggers such as major life stressors, sleep deprivation, and substance use (particularly amphetamines and cannabis) can precipitate the first episode or accelerate relapse. Circadian rhythm stability is also critical: irregular sleep-wake patterns directly undermine mood stability.
Common Symptoms
Manic / Hypomanic Episode
According to DSM-5 criteria[1], a manic episode must last at least 7 days (hypomania at least 4 days) and involve elevated, expansive, or irritable mood with increased energy, plus at least three of the following (four if the mood is only irritable):
- Inflated self-esteem or grandiosity
- Decreased need for sleep (e.g. feeling rested after only 3 hours)
- More talkative than usual or pressure to keep talking
- Flight of ideas or subjective experience that thoughts are racing
- Distractibility (attention easily drawn to irrelevant stimuli)
- Increase in goal-directed activity or psychomotor agitation
- Excessive involvement in activities with a high potential for painful consequences (e.g. spending sprees, risky sexual behaviour, reckless investments)
Depressive Episode
The depressive phase of bipolar disorder shares virtually all symptoms with major depression (persistent low mood, loss of interest, sleep and appetite changes, fatigue, worthlessness, poor concentration, suicidal ideation). However, several features are more common in bipolar depression than unipolar depression: hypersomnia (rather than insomnia), increased appetite and weight gain, leaden paralysis (a heavy sensation in the limbs), and heightened sensitivity to interpersonal rejection[3].
Clinically, most people with bipolar disorder spend far more time depressed than manic. This is especially true in bipolar II, where depressive episodes may account for more than two-thirds of the illness course, explaining why so many patients are initially misdiagnosed with unipolar depression.
Treatment Options
Medication
Medication for bipolar disorder is fundamentally different from that for unipolar depression. International guidelines are clear: mood stabilisers and atypical antipsychotics form the backbone of treatment, not antidepressants[8]. Using an antidepressant alone in bipolar disorder can trigger mania or accelerate mood cycling.
Commonly prescribed bipolar medications
| Medication | Class | Key Features |
|---|---|---|
| Lithium | Mood stabiliser | The most established mood stabiliser, with the strongest evidence for anti-suicide efficacy. Requires regular blood level monitoring[9] |
| Valproate | Mood stabiliser | Rapid onset for acute mania. Women of childbearing age should be aware of teratogenic risk |
| Lamotrigine | Mood stabiliser | Best evidence for preventing depressive relapse. Dose must be titrated slowly to avoid serious skin reactions[10] |
| Quetiapine | Atypical antipsychotic | Effective in both manic and depressive phases; low doses also help with sleep |
| Aripiprazole | Atypical antipsychotic | Relatively fewer metabolic side effects, strong evidence for mania |
| Olanzapine | Atypical antipsychotic | Potent for acute mania, but weight gain and metabolic risk require monitoring |
Bipolar disorder typically requires long-term, often lifelong, maintenance treatment. Many patients stop their medication once they feel stable, which is the single biggest risk factor for relapse. Those on lithium need blood tests every 3 to 6 months to check lithium levels, thyroid function, and kidney function.
Psychotherapy
Psychotherapy in bipolar disorder serves to augment medication, improve adherence, and help patients recognise early warning signs of relapse. The main evidence-based approaches are:
- Cognitive Behavioural Therapy (CBT): Helps patients identify early manic warning signs (such as reduced sleep, proliferating plans), manage depressive thinking patterns, and build a regular daily structure[11]
- Psychoeducation: Teaches patients and family members about the nature of the illness, how medications work and their side effects, and risk factors for relapse. Systematic psychoeducation has been shown to significantly reduce relapse rates[12]
- Interpersonal and Social Rhythm Therapy (IPSRT): Combines interpersonal therapy with stabilisation of daily social rhythms. By establishing regular patterns of sleep, exercise, and social engagement, IPSRT helps stabilise mood. Particularly well-suited for patients whose routines are chaotic
rTMS Treatment
Repetitive Transcranial Magnetic Stimulation (rTMS) in bipolar disorder is primarily explored for bipolar depression. Preliminary studies suggest that stimulating the left dorsolateral prefrontal cortex can improve depressive symptoms, though the evidence base remains less robust than for rTMS in unipolar depression[13].
An important caveat is that rTMS in bipolar disorder should be administered under the protection of a mood stabiliser to minimise the risk of triggering mania. While rTMS is not yet listed as a standard treatment for bipolar disorder, it is an emerging option worth discussing with your psychiatrist if you have not responded adequately to medication during a depressive phase.
Self-Assessment
The MDQ (Mood Disorder Questionnaire) is the most widely used screening tool for bipolar disorder. It consists of 13 yes/no questions asking whether you have ever experienced the typical features of a manic or hypomanic episode during the same period of time. The MDQ is not a diagnostic instrument, but if you answer "yes" to 7 or more of the 13 items, and these symptoms occurred simultaneously and caused at least moderate functional impairment, a psychiatric evaluation is strongly recommended[14].
It is especially worth noting that if you have been treated for depression with multiple antidepressants without adequate improvement, the probability of a positive MDQ result is higher than in the general population. Reassessing the diagnostic direction is often the key to breaking through a treatment plateau.
Go to the online self-assessment tool (MDQ)
When to Seek Help
Consider booking a psychiatric consultation if any of the following apply to you:
- Mood swings that are intense and rapid, with days of being "on top of the world" followed by a sudden crash
- Periods when you barely needed sleep yet felt full of energy, and in hindsight you did not feel like your usual self
- Impulsive spending, reckless decisions, or unusual social behaviour that you regretted afterward
- Two or more antidepressants have failed to produce meaningful improvement
- A family member has been diagnosed with bipolar disorder
- Thoughts of self-harm or suicide
Bipolar disorder requires lifelong management, but with the correct diagnosis and appropriate medication, most patients can maintain stable moods and a good quality of life[8]. The most important thing is to resist the temptation to stop medication because "I feel fine now." That decision is the single most common cause of relapse.
If you are in crisis right now, please call the Taiwan Suicide Prevention Hotline at 1925 (24 hours, free) or go to the nearest emergency department.
References
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR). Washington, DC: APA; 2022.
- Merikangas KR, Jin R, He JP, et al. Prevalence and correlates of bipolar spectrum disorder in the World Mental Health Survey Initiative. Arch Gen Psychiatry. 2011;68(3):241-251. DOI PubMed
- Grande I, Berk M, Birmaher B, Vieta E. Bipolar disorder. Lancet. 2016;387(10027):1561-1572. DOI PubMed
- McGuffin P, Rijsdijk F, Andrew M, et al. The heritability of bipolar affective disorder and the genetic relationship to unipolar depression. Arch Gen Psychiatry. 2003;60(5):497-502. DOI PubMed
- Ashok AH, Marques TR, Jauhar S, et al. The dopamine hypothesis of bipolar affective disorder: the state of the art and implications for treatment. Mol Psychiatry. 2017;22(5):666-679. DOI PubMed
- Hashimoto K, Sawa A, Iyo M. Increased levels of glutamate in brains from patients with mood disorders. Biol Psychiatry. 2007;62(11):1310-1316. DOI PubMed
- Hibar DP, Westlye LT, Doan NT, et al. Cortical abnormalities in bipolar disorder: an MRI analysis of 6503 individuals from the ENIGMA Bipolar Disorder Working Group. Mol Psychiatry. 2018;23(4):932-942. DOI PubMed
- 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
- Geddes JR, Burgess S, Hawton K, et al. Long-term lithium therapy for bipolar disorder: systematic review and meta-analysis of randomized controlled trials. Am J Psychiatry. 2004;161(2):217-222. DOI PubMed
- Geddes JR, Calabrese JR, Goodwin GM. Lamotrigine for treatment of bipolar depression: independent meta-analysis and meta-regression of individual patient data from five randomised trials. Br J Psychiatry. 2009;194(1):4-9. DOI PubMed
- Chiang KJ, Tsai JC, Liu D, et al. Efficacy of cognitive-behavioral therapy in patients with bipolar disorder: a meta-analysis of randomized controlled trials. PLoS One. 2017;12(5):e0176849. DOI PubMed
- Colom F, Vieta E, Martinez-Aran A, et al. A randomized trial on the efficacy of group psychoeducation in the prophylaxis of recurrences in bipolar patients whose disease is in remission. Arch Gen Psychiatry. 2003;60(4):402-407. DOI PubMed
- McGirr A, Karmani S, Engemann DA, et al. Clinical efficacy and safety of repetitive transcranial magnetic stimulation in acute bipolar depression. World Psychiatry. 2016;15(1):85-86. DOI PubMed
- Hirschfeld RM, Williams JB, 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
Want to book with Dr. Tam?
Attending psychiatrist at Ten-Chan General Hospital and Tien-Hsiang Hospital, Zhongli. Consultations in English, Mandarin, and Cantonese.
View clinic hours & book