Bipolar disorder is a mental health condition characterised by significant shifts in mood, energy, and activity, ranging from depressive episodes to periods of elevated mood. The condition has several subtypes, most commonly Bipolar I and Bipolar II, which differ in severity, symptom patterns, and treatment approaches. The World Health Organization estimates that in 2021 there were approximately 37 million people living with bipolar disorder (World Health Organisation, 2023), highlighting the importance of understanding Bipolar I vs Bipolar II symptoms and treatment strategies.
In brief, Bipolar I involves experiencing at least one full manic episode that significantly disrupts daily functioning or requires hospital treatment and typically lasts at least seven days (or any length of time if hospitalisation is needed). In comparison, Bipolar II is defined by hypomanic episodes, less intense periods of elevated mood, alongside recurrent major depressive episodes, which can be prolonged and distressing (American Psychiatric Association, 2013). Understanding these distinctions helps clinicians, patients, and carers recognise each subtype’s presentation and choose effective management strategies (Lewis et al., 2003). This blog will help to explore and understand the differences between Bipolar I and Bipolar II.
Bipolar I disorder is characterised by extreme mood changes, including at least one manic episode (American Psychiatric Association, 2013). A manic episode is a period of very high, expansive, or irritable mood lasting at least a week and may include increased energy, reduced need for sleep, rapid speech, racing thoughts, inflated self-esteem, and impulsive or risky behaviour (World Health Organisation, 2023; NHS, 2024).
Mania in Bipolar I can severely affect daily life and sometimes requires hospital care. Depressive episodes may also occur, presenting with low mood, reduced energy, and difficulty performing daily activities. While experiencing depression is not required for diagnosis, these episodes often last weeks or months. Bipolar I disorder can disrupt sleep, concentration, relationships, and decision-making, making it challenging to maintain routines at home, school, or work (NIHR, 2025).
Bipolar II disorder is characterised by at least one major depressive episode and at least one hypomanic episode, with no history of full manic episodes (American Psychiatric Association, 2013; Coryell et al., 2025). A hypomanic episode is a period of persistently elevated, expansive, or irritable mood, along with increased energy or activity, lasting at least four consecutive days.
Unlike full mania, hypomania does not severely disrupt daily life, require hospitalisation, or include psychotic features. People with Bipolar II typically spend more time in depressive states, which can lead to misdiagnosis as unipolar depression if a careful history of mood changes is not taken. Both hypomanic and depressive episodes can significantly impact daily functioning, relationships, and routines (Millet et al., 2010). During depressive episodes, people may feel sad, tired, and lose interest in daily activities, making it hard to work, study, socialise, or keep routines. Even though hypomanic episodes are milder than full mania, they cause changes in energy, sleep, mood, and behaviour that can disrupt daily functioning and relationships (Millet et al., 2010).
|
Clinical Feature |
Bipolar I |
Bipolar II |
|
Mania |
Present and severe (at least one episode) |
Absent
|
|
Hypomania |
Bipolar I more associated with mania |
Associated with Bipolar II |
|
Depression
|
Common but not required for diagnosis |
Depressive episodes are required for diagnosis
|
|
Psychosis |
May occur during mania |
Not present during hypomanic episodes |
|
Hospitalisation
|
High risk during mania |
Lower risk
|
|
Risk
|
Higher risk during manic episodes (impulsivity, hospitalisation) |
High suicide risk due to recurrent depression
|
|
Functional disruption |
Significant during mania |
Mild to moderate during hypomania |
Treatment for both Bipolar I and Bipolar II focuses on stabilising mood, preventing relapse, and managing symptoms over the long term (NICE, 2014; NHS, 2024). Individualised plans typically combine medication, psychological therapies, and lifestyle support (Mind, 2022).
Medication is central and may include mood stabilisers, antipsychotics, and, in some cases, antidepressants. Antidepressants are used cautiously in bipolar disorder due to the risk of mood switching and are typically prescribed alongside a mood stabiliser (American Psychiatric Association, 2013; Malhi, 2015).
Psychological therapies, such as Cognitive Behavioural Therapy (CBT), help individuals understand mood patterns, recognise early warning signs, and develop coping strategies. Psychoeducation and family-focused therapy support both patients, families and carers in managing symptoms and preventing relapse (NICE, 2014; Miklowitz, 2008; Mind, 2022).
Lifestyle management includes maintaining a regular sleep routine, managing stress, establishing daily structure, and tracking mood changes (World Health Organization, 2023).
While both subtypes share core treatment approaches, management priorities differ:
This integrated treatment approach helps individuals maintain stability, reduce symptom severity, and improve quality of life over time.
Understanding whether someone has Bipolar I or Bipolar II is crucial for ensuring an accurate diagnosis and appropriate treatment. Correct identification of symptoms helps clinicians choose the most suitable medications and psychological interventions, reducing the risk of ineffective or potentially harmful treatment (American Psychiatric Association, 2013). This distinction also helps individuals and families better understand symptom patterns, recognise early warning signs, and seek timely support. Importantly, Bipolar II is frequently misdiagnosed as unipolar depression, as hypomanic episodes may be subtle or not recognised by the individual and or family. Misdiagnosis can delay appropriate treatment and contribute to ongoing symptoms or relapse.
Bipolar I and Bipolar II are both serious mental health conditions, but they differ in the type and severity of mood episodes experienced. Greater awareness of these differences, along with early recognition and appropriate treatment, can significantly improve long-term outcomes. With appropriate support, many people living with bipolar disorder can manage their symptoms effectively and maintain a good quality of life (NHS, 2024; WHO, 2023).
Living with bipolar disorder can be challenging. While medication, psychological therapies and lifestyle support remain first line treatments, Transcranial Magnetic Stimulation (TMS) offers additional hope. TMS is a non-invasive treatment using magnetic pulses to stimulate brain areas involved in mood regulation, particularly the prefrontal cortex. TMS is approved for treatment-resistant depression and is increasingly being studied and used off-label for bipolar depression (Nguyen et al., 2021). At Smart TMS, patients receive protocols tailored to their condition and clinical history. This approach combines TMS with clinical monitoring and support from Practitioners, helping improve symptom management, prevent relapse, and better understand treatment responses to neuromodulation. Read more about TMS for bipolar disorder at Smart TMS.
Written by Holly Brown, Smart TMS Newcastle Practitioner