What Is The Difference Between Bipolar 1 And Bipolar 2?

Bipolar disorder is a mental health condition characterized by extreme mood shifts. Those with bipolar disorder may experience periods of mania or depression that can last for weeks.

Around 4.4% of the US population¹ have been diagnosed with bipolar disorder at some point in their lives. Men and women are equally affected by this mood disorder, with most developing their first symptoms around the age of 25.

It is possible for teens and children to have bipolar disorder, but it's rare.

Bipolar-related disorders fall into four categories, as defined by the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5)². The differences between each type of bipolar are primarily in the severity and length of the mood episodes. Bipolar I and bipolar II disorders are the most common types, with cyclothymic and other specified and unspecified bipolar and related disorders being less common.

While the symptoms of each type of bipolar disorder are slightly different, the treatment for each is largely the same. It usually involves a combination of medication and therapy. Bipolar disorder is a lifelong condition, but with the right treatment, those experiencing bipolar symptoms can lead happy productive lives.

What is bipolar I disorder?

Bipolar I disorder is characterized by extreme, intense mood episodes. Those with bipolar I experience intense mania, which lasts at least seven days. These mania episodes are followed or preceded by a period of depression, which lasts at least two weeks.

During a manic mood episode, someone with bipolar I will experience a period of abnormally elevated, expansive, or irritable mood and increased activity or energy.

They may also experience:

• A reduced need for sleep and excessive energy 

• Inflated feelings of self-confidence and self-importance

• Involvement in risky and potentially harmful behavior, such as spending too much money or having risky sex

• Being more talkative than usual 

• Racing thoughts that they aren't able to control or slow down

• Distractibility 

• A desire to take on a lot of projects or tasks all at the same time

During a depressive mood episode, they might experience:

• Feelings of hopelessness

• Depressed mood most of the day, nearly every day 

• Irritability or restlessness

• An inability to focus on tasks

• A lack of desire to participate in events or hobbies they used to enjoy

• Thoughts of suicide

• Change in weight 

• Change in sleep pattern 

• Fatigue or loss of energy 

• Poor concentration 

• Reduced or slowed motor activity

Bipolar I tends to be the most severe of the bipolar disorders. The manic episodes are very noticeable by others and may severely interfere with daily life or the ability to function at work.

For those with a bipolar I diagnosis, manic episodes can become so intense that they require hospitalization to prevent the person from hurting themselves or others.

What is bipolar II?

Those with bipolar II disorder also experience mood cycling, having episodes of both highs and lows. However, those with bipolar II disorder don't have manic episodes like those experienced by people with bipolar I disorder.

People with bipolar II experience hypomanic episodes, which might include:

• Feeling happy or excited most of the time

• Being easily distracted or unable to focus on tasks

• Having excessive amounts of energy

• Decreased need for sleep 

• Racing thoughts 

• Increased goal-directed activity

While these symptoms are like those experienced during a bipolar I manic episode, hypomania is less intense. It is much less likely to interfere with your daily life or your job. It's also very unlikely to require hospitalization, unlike an episode of mania. These hypomania episodes also last a shorter amount of time than a manic episode, usually only around four or five days.

Hypomanic episodes experienced by those with bipolar II will follow or precede episodes of severe depression. The depressive episodes experienced by people with bipolar II are similar to those experienced by people with bipolar I. Episodes of depression experienced with bipolar II may last two weeks or longer.

It's possible for those with bipolar II to experience periods of stable moods between hypomanic and depressive episodes. To be diagnosed with bipolar II, you must have experienced at least one episode of hypomania and one episode of depression.

What are the main differences between bipolar I and II?

The biggest differences between bipolar I and bipolar II are the length and severity of the mood episodes. In bipolar I, individuals experience manic episodes which impact their social and occupational functioning and they may require hospitalization.

Those with bipolar II experience hypomanic episodes only. These do not interfere with the individual's social and occupational functioning and the person does not require hospitalization.

Individuals with bipolar I and II both experience depressive episodes. There is some research that suggests the depressive episodes in bipolar II may be longer and more severe than those in bipolar I. 

Bipolar I

• Manic episodes lasting a week or more

• Depressive episodes lasting two weeks or more

Bipolar II

• Hypomanic episodes lasting four days or more

• Major depressive episodes lasting two weeks or more

Do bipolar I and bipolar II have different treatment options? 

While the symptoms of bipolar I and bipolar II may be different, the treatments are largely the same. The most common forms of treatment are therapy and medication, including:

• Mood stabilizers such as lithium, sodium valproate, and lamotrigine. These medications can help prevent mood episodes and mood cycling. 

• Antipsychotics such as risperidone or aripiprazole. These are often prescribed with mood stabilizers and can help prevent more serious manic symptoms, such as hallucinations. 

• Antidepressants. These can help manage symptoms experienced during depressive episodes and can help prevent the episodes from becoming more severe.

Determining what combinations and types of medication work to help control the symptoms of bipolar disorder for each individual can take time. Everyone responds to medication differently. Stick with your current treatment plan, but talk to your doctor if your symptoms are becoming worse.

Are there any other types of bipolar disorder?

While bipolar I and bipolar II are the most common types of bipolar disorder, they aren't the only ones. The DSM-5 lists two additional types of bipolar disorders:

Cyclothymic disorder (or cyclothymia)

Those with cyclothymia experience hypomania and depressive symptoms that do not meet the criteria for hypomanic or depressive episodes. Although the severity of the symptoms is not as severe as bipolar I or II, the symptoms generally last longer.

The mood episodes can last two years or longer in adults and a year or longer in children.

While the symptoms of these types of bipolar disorders may not be as severe as bipolar I or II, it's still important to get treatment as these symptoms can impact your social or occupational functioning.

Other specified and unspecified bipolar and related disorders

Those with other specified and unspecified bipolar disorders may experience some symptoms associated with bipolar, such as mania or depression. However, their symptoms won't fit into the defined categories of the other bipolar types.

Specified bipolar and related disorders are diagnosed when the doctor chooses to communicate exactly why the presentation does not meet the criteria of the other categories. For example, the person might have hypomania without the corresponding episodes of depression experienced with bipolar II. Or they might experience short durations of hypomanic episodes (two to three days) and major depressive episodes.

A diagnosis of unspecified bipolar and related disorders is used when the clinician chooses not to specify the reasons that the criteria are not met for specific bipolar and related disorders. This may occur when the doctor does not have sufficient information, for example, when they are reviewing the patient in an emergency department setting.

The symptoms for other specified and unspecified bipolar and related disorders might be similar to classic bipolar symptoms, but may not happen often enough or be severe enough for a diagnosis of one of the other bipolar types. However, a bipolar diagnosis of this kind may help someone gain access to the medical treatment they might not get otherwise.

Bipolar disorder is a spectrum of severity. Some classifications may be more severe than others, but no matter where your mood disorder falls on the spectrum, it's important to seek help.

If you are experiencing mood episodes that interfere with your daily life, make an appointment with your doctor. They can work with you to develop a treatment plan to help stabilize your moods.

The lowdown

Bipolar disorder is characterized by mood episodes, cycling between manic or hypomanic and depressive moods. The two most common types of bipolar disorder are bipolar I and bipolar II.

Those with bipolar I experience intense episodes of mania. During these episodes, they may have feelings of self-importance, engage in risky behavior like overspending or speeding, or be unable to control racing thoughts.

These episodes last at least seven days. Those with bipolar I also experience depressive episodes which may precede or follow the manic episodes. The depressive episodes last at least two weeks.

Those with bipolar II experience hypomanic episodes which are less severe than the manic episodes experienced in bipolar I. These individuals also have depressive episodes similar to those in bipolar I.

Cyclothymia and other specified and unspecified bipolar and related disorders are two additional bipolar classifications that don't fit into the typical symptoms experienced in bipolar I and bipolar II.

Despite their differences, all forms of bipolar disorder are generally treated with a combination of medication and therapy. With the right treatment, those with this mental health condition can lead healthy, happy, and productive lives.