Bipolar Disorder, Major Depression, and PMDD Differences

Mood disorders cause extreme fluctuations in an individual’s emotional and mental health, so it’s vital that they are correctly diagnosed in order to administer treatment. However, diagnostic issues commonly arise due to the similarities between key signs and symptoms of different disorders.

Bipolar disorder (BD) and major depression disorder (MDD) are two mood disorders that are commonly misdiagnosed in people of both genders, and women suffering symptoms of premenstrual dysphoric disorder (PMDD) are also frequently misdiagnosed with one of the other disorders instead. Being able to identify characteristic symptoms of each disorder correctly is the surest way to provide proper treatment.

What is Bipolar Disorder?

Bipolar disorder is a serious mood disorder characterized by recurrent manic and depressive episodes. The disorder is a spectrum of two types: BD-I and BD-II.

BD-I is characterized by at least one manic episode and a preceding or successive depressive episode. BD-II is distinguished by a hypomanic episode and a major depressive episode. Common symptoms include mood fluctuations, verbal outbursts, increased irritability, and difficulties concentrating^[1].

What is Major Depressive Disorder?

Major depressive disorder is one of the most dangerous mood disorders, predicted by WHO to become the highest-ranked global burden of disease by 2030. Its primary symptoms include a persistent low mood, lack of interest in social activities, poor sleep, lack of energy, and feelings of poor self-esteem. Despite some overlapping symptoms, the difference between bipolar and depression is that MDD is characterized by a continuous low mood, whereas BD has alternating phases of depression and mania^[2].

What is Premenstrual Dysphoric Disorder (PMDD)?

Premenstrual dysphoric disorder affects women during the weeks before menstruation, with symptoms far more severe than is typical for premenstrual syndrome (PMS). The exact cause of PMDD is not known, but its symptoms are believed to be associated with surges in hormones such as estrogen and progesterone. PMDD stands out due to symptoms such as significantly low mood, noticeable anxiety, worrying changes to sleep and appetite, increased conflict and irritability when interacting with others, and emotional breakdowns. These symptoms can become so debilitating that they interfere with the individual’s ability to navigate daily life and cyclically re-occur with each menstrual cycle^[3].

Comparing Symptoms

With overlapping symptoms lending themselves to misdiagnoses of major depression, bipolar disorder, and premenstrual dysphoric disorder, it’s important to recognize the key differences that distinguish them from each other.

PMDD vs. Bipolar

PMDD and BD both involve depressive periods, but neither are defined solely by low mood, nor are they wholly comparable disorders. The biggest difference between their symptoms is when they occur.

For those suffering from PMDD, the symptoms are specifically related to a phase in the menstrual cycle, with similar symptoms observed within two or more consecutive cycles^[3]. On the other hand, symptoms of bipolar are observed during random periods when the individual experiences a depressive episode. Though individuals with BD experience some symptomatic cycling, it lacks the biological accuracy of PMDD^[1].

Bipolar disorder is also distinguished by its combination of mania and depression. During a manic episode, an individual experiences a range of different emotions, including excitement, guilt, irritability, energization, and impulsivity. These episodes can last for days or even weeks, with a noticeable peak in either joy or touchiness^[1].

By comparison, there is no such comparable mania with PMDD. All of the mood-related symptoms are low, including poor self-esteem, decreased interest in activities, lack of energy, and a retreat into one’s own thoughts^[3].

Bipolar vs. Depression

Bipolar disorder is one of the more commonly misdiagnosed mood disorders, especially as it has so many similarities to major depressive disorder. Patients with BD who exhibit more depressive symptoms than manic symptoms are often misdiagnosed with MDD, which can lead to the prescription of manic episode-inducing antidepressants. It’s crucial that both sides of BD – mania and depression – are distinguished and receive appropriate care^[4].

MDD is characterized by persistent low mood and feelings of worthlessness, presenting as noticeable depression only. BD depressive episodes, on the other hand, lack that consistency, and once a depressive episode has ended, the individual’s mood may become elevated again or fluctuate depending on whether or not a manic episode has been triggered.

Those with MDD typically don’t show signs of improved mood nor the same amount of energy that may be present in a person with BD. However, many BD patients present with depressive episodes first, which then overshadow other essential parts of their diagnosis and result in the incorrect conclusion of MDD^[4].

Depression vs. PMDD

As with bipolar vs depression, there is also a huge issue with PMDD being misdiagnosed as depression when women complain of similar symptoms. The introduction of PMDD as a recognized disorder has been controversial because there’s a chance that women may be misdiagnosed. PMDD is indicated by “significant distress” during the premenstrual phase, but also affective symptoms like joint pain, tiredness, and difficulties concentrating^[5].

The difference between depression and PMDD is, again, that depression is characterized by a persistent low mood. The symptoms of MDD are usually brought on by a trigger, such as the death of a loved one, divorce, or personal trauma, and then they continue to debilitate the individual in the long term^[2].

Though PMDD is cyclical, it occurs in response to hormonal changes during the menstrual cycle, setting it apart from MDD. Though there are mixed feelings around PMDD diagnoses, there is a strict set of criteria for medical professionals to follow in order to avoid misdiagnosing women^[5].

What Impact Do These Disorders Have?

Severe mood disorders can make various aspects of everyday life, such as work, social activities, household responsibilities, and personal relationships, more difficult. Individuals with bipolar disorder almost always suffer a poorer quality of life than those without it, particularly due to the depressive symptoms. Frequent mood fluctuations and increased irritability make it harder to maintain successful personal and professional relationships, which impacts how these individuals function during everyday life^[6].

Individuals diagnosed with MDD suffer similar everyday impacts, though the severity of the low mood and feelings of emptiness and worthlessness further impair functionality. There is an increased risk of suicide for those who don’t receive treatment or support, usually pre-dated by instances of social withdrawal, extreme sadness, and an overall diminished quality of life^[7]. Those who don’t have strong interpersonal relationships are particularly at risk of developing more severe MDD, causing them to subsequently withdraw further from society and any supportive outlets^[2].

As for PMDD, the emotional and hormonal changes that occur during the menstrual cycle make it almost impossible to maintain a good quality of life. Most women experience PMS symptoms that don’t interfere with their everyday lives, but PMDD impairs functionality in several ways. Emotionally, it causes a decreased interest in socializing, makes it harder to concentrate at work, and makes even the smallest responsibilities feel beyond their control. There are also physical impacts, with some individuals suffering bad headaches, breast tenderness, and aching muscles, which make them more lethargic and withdrawn.^[3]

Diagnostic Challenges

The biggest threat to an accurate mood disorder diagnosis is the existence of overlapping symptoms. There’s a long history of bipolar disorder being misdiagnosed as depression, particularly due to the similarities between BD-II and MDD, with more than 50% of BD patients receiving a misdiagnosis.

Individuals with BD usually experience a depressive episode before a manic one, leading to the hasty “depression” label. With BD-II, the hypomanic episode is mild, but the depressive symptoms are far more noticeable, so it can be challenging to correctly observe mania alongside signs of depressed mood.^[8]

Similar diagnostic challenges are presented by bipolar disorder and PMDD, with both being characterized by their cyclical presentations and fluctuating symptoms. Premenstrual dysphoric symptoms occur every month, usually a week or two before menstruation begins, with most women with PMDD experiencing around six days of grievous symptoms per cycle^[3].

BD can “cycle” in a similar way, though it’s unlikely for someone to experience an episode every month. The chronic mood swings caused by depressive episodes can be likened to PMDD symptoms, making it harder for women with either or both disorders to receive an accurate diagnosis^[1].

Treatment Similarities and Differences

Once each mood disorder has been correctly diagnosed, treatment can begin. Certain medications can be used to treat different mood disorders, but not always. For example, individuals with BD or MDD may both be prescribed antidepressants for depressive symptoms, but those with BD must also take a mood stabilizer. This is because antidepressants can trigger manic episodes or cause bipolar to rapidly cycle, which a mood stabilizer will fix. Psychotherapy is a non-medicated form of treatment that people with depression and BD can benefit from because it gives them an outlet to discuss their mental well-being^[9].

PMDD doesn’t have the same long history of research behind it as BD and MDD do, so treatment options are often quite different. There are several non-medicated methods of treatment, such as increased exercise, dietary changes, and relaxation habits, which all aim to boost serotonin and decrease feelings of anxiety.

Antidepressants are usually not very effective for PMDD, so Serotonin Reuptake Inhibitors (SRIs) are more likely to be prescribed for debilitating emotional and hormonal symptoms. SRIs treat symptoms more quickly, which is pertinent for a cyclically-occurring disorder^[3].

Comorbidity of Bipolar, Major Depression, and PMDD

Comorbidity poses a unique challenge to those diagnosed with a mood disorder. Not only can multiple mood disorders co-exist, but other mental health conditions may emerge, too. In the case of PMDD vs bipolar disorder, an overlap can cause the symptoms of both to become more severe in female patients. Women with PMDD are one of the demographics most likely to develop symptoms of BD, with an increased number of mood episodes, and the hormonal changes that occur due to PMDD can make BD symptoms more severe^[10].

And despite both having depressive symptoms, BD and PMDD can also dually exist for individuals suffering from major depression. In fact, depressive mood disorders are some of the most common comorbidities for MDD, as well as anxiety disorders, substance use disorders, and other psychiatric disorders. It’s vital that comorbid disorders are individually recognized, but a dual diagnosis treatment plan may be administered to simultaneously treat symptoms and reduce the possibility of an individual suffering further symptoms alongside those of MDD, BD, or PMDD^[11].