Borderline personality disorder (BPD) and bipolar disorder are mental health conditions that share some similar features. Health care providers sometimes misdiagnose one as the other, and it's also possible to have both conditions at the same time. Learning the key differences and similarities can help you or your loved one understand what's going on and how to best manage BPD or bipolar disorder.

3 Differences Between BPD and Bipolar Disorder

The differences between BPD and bipolar disorder can be tough to spot. Mental health professionals can determine an accurate diagnosis and develop a plan to treat your condition.

1. Periods of Stable Mood

People with BPD and bipolar disorder both experience periods of high moods (mania) and low moods. However, a person with bipolar disorder is more likely to have a stable mood between these mood shifts, while someone with BPD is more likely to be consistently depressed.

There are a few subtypes of bipolar disorder. Bipolar 1 disorder, the most common, includes manic and depressive episodes. With bipolar 2 disorder, people don’t experience the same intense mania as bipolar 1.

People with different forms of bipolar disorder can go for long stretches without symptoms, developing healthy relationships and functioning well in daily life. In contrast, symptom-free periods are less common in BPD, as emotional instability tends to be more persistent. “I wouldn’t know a typical day if it smacked me in the face,” a MyDepressionTeam member said. “With borderline personality disorder, I don’t think I even have typical minutes.”

2. Reactivity to Triggers

Mood changes in BPD are usually triggered by specific events, like rejection or negative experiences. While it’s normal to feel upset, people with BPD feel these emotions more intensely. Although brain chemistry can also contribute, BPD is primarily influenced by life experiences, whereas bipolar disorder is more rooted in brain chemistry.

Mood swings in bipolar disorder can seem to come out of nowhere. That’s because they’re rooted in abnormal brain chemistry rather than personality issues, like having a skewed sense of self. This key difference is why people with BPD versus bipolar disorder benefit from different treatment approaches.

3. Different Treatments

Dialectical behavior therapy is a treatment designed for people with BPD. It helps people manage intense emotions and build better relationships. This type of therapy also teaches ways to avoid harmful behaviors.

Mood stabilizers such as lithium are a cornerstone treatment for bipolar disorder. They help avoid manic episodes and make mood swings less severe.

Medication isn’t generally recommended for BPD, although medicines such as anti-anxiety drugs may help with certain symptoms. There’s been some interest in the potential benefits of mood stabilizers for BPD, but some researchers and doctors aren’t convinced that these are an appropriate treatment option. They believe the drugs’ risks may outweigh the positive effects in some cases for people with BPD.

A specialist is best equipped to understand the differences in treatment for BPD and bipolar disorder. General therapists can offer support, but they may not fully address the complex needs of these two distinct conditions.

4 Similarities Between BPD and Bipolar Disorder

There are many similarities between BPD and bipolar, making it difficult to get an accurate diagnosis.

1. Difficulty Getting the Right Diagnosis

It can take up to 10 years for someone to be accurately diagnosed with bipolar disorder. Similarly, BPD is often underdiagnosed. Both mood disorders may be mistaken for depression, which is a common symptom. Both conditions can also co-occur with depression.

2. Dramatic Mood Swings

One major similarity between BPD and bipolar disorder is mood swings. People with both conditions can shift quickly between high and low moods.

“Borderline is kicking my butt right now. I’m overthinking, my anger is off the charts, and I’m so full of anxiety that I haven’t eaten in two days. I’m feeling very alone and worthless,” shared a MyDepressionTeam member.

Intense mood changes can affect all areas of life, from keeping a job to maintaining healthy relationships. Recognizing that a mental illness is causing these mood swings can help reduce any related feelings of guilt or shame, reinforcing that it’s OK to seek professional help.

3. Family History

Both bipolar disorder and BPD may have a genetic link and tend to run in families. If a close family member, such as a parent or a sibling, has one of these conditions, your risk of developing it is higher.

Scientists are working to identify the specific genes linked to BPD and bipolar disorder. A combination of genetic and environmental factors likely contributes to higher rates among family members.

4. Overlapping Treatments

The treatments for BPD and bipolar disorder aren’t the same, but those with both conditions can benefit from therapy and healthy lifestyle changes. These lifelong conditions require ongoing care.

Psychotherapy, also known as talk therapy, is particularly emphasized for BPD but can benefit either condition. Both group sessions and individual counseling can help increase self-awareness and teach communication strategies. Psychotherapy can also support family members who want to understand and help a loved one with BPD or bipolar disorder.

Routines like good sleep habits and regular exercise have a positive impact on mental health. These habits promote physical and mental well-being, especially when managing BPD or bipolar disorder. It’s important for people with these conditions to find the right support. Therapists and support groups can help them stay on track with treatment and prevent isolation from depression.

Living With Both Conditions

Most people with BPD or bipolar disorder don’t have both conditions at the same time. However, research suggests that a double diagnosis happens in about 10 percent to 20 percent of cases.

“I deal with depression also, but now my symptoms are more borderline personality disorder than bipolar, which is my diagnosis. I was more scared of BPD than bipolar. I am still afraid, as I don’t want my personality to be more of a mess,” wrote a member of MyDepressionTeam.

Managing more than one mental health condition can feel overwhelming, but with the right support, it’s possible to live well. If you’re having trouble managing your symptoms, talk to your health care team. They may refer you to a specialist or review your treatment plan to make sure you’re getting the right care.

Talk With Others Who Understand

MyDepressionTeam is the social network for people with depression and other related mental health disorders. On MyDepressionTeam, more than 148,000 members come together to ask questions, give advice, and share their stories with others who understand life with conditions like borderline personality disorder and bipolar disorder.

What symptoms of BPD or bipolar disorder impact your life and interpersonal relationships? What treatments and coping strategies do you find helpful? Share your experience in the comments below, or start a conversation by posting on your Activities page.