Exploring mixed episodes in bipolar I disorder: When mania and depression travel together
Each year, World Bipolar Day is an opportunity to raise awareness and deepen understanding of bipolar disorder, a condition affecting about 7 million adults in the United States. Bipolar I disorder (BD-I) is a brain-based condition influencing mood and energy regulation to a degree that impacts functioning in daily life.
Clinically, BD-I is defined by the presence of at least one manic episode. During a manic episode, people living with BD-I experience an extreme increase in energy, with other symptoms including decreased need for sleep, racing thoughts, impulsivity, or feeling invincible. In more severe cases, it can include psychosis. Depression, which is associated with feelings of sadness, hopelessness, low motivation, and changes in sleep or appetite that are serious enough to be disruptive in a person’s life, often follows or alternates with mania.
The term ‘bipolar disorder’ tends to evoke a presumption of two distinct poles, with mania on one side and depression on the other. That framework is helpful for understanding the illness at a basic level, but the brain does not always behave that neatly. BD-I is a complex condition, presenting differently across patients and even within the same individual over time.
One of the most misunderstood and often overlooked aspects of BD-I is the occurrence of mixed episodes. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR), roughly one third of people living with bipolar disorder experience mixed features during mood episodes. Yet, despite how common they are, mixed presentations are not always easily or consistently recognised in clinical settings.
Mixed episodes are identified by concurrent symptoms of depression and mania. A person may meet criteria for a manic episode while also experiencing several depressive symptoms, or they may be in a depressive episode while showing signs of manic activation. In other words, the mood states overlap, rather than present separately. When I explain this to patients, I often use a simple analogy: it can feel like having the brakes and the accelerator engaged simultaneously, creating an internal tension that is both distressing and destabilising. Because those symptoms pull in different directions at once, mixed episodes can be confusing for patients and challenging for clinicians to recognise.
Why mixed episodes may be missed
One reason mixed episodes may be underreported is that mania itself as a symptom is harder to clinically observe. Patients less commonly approach their healthcare provider with complaints related to mania. To the contrary, many will report positive personal associations with the productivity and feelings of euphoria arising during a manic state. It is much more common for people living with BD-I to seek help when they are depressed. The emotional weight of depression, the loss of motivation, and the disruption to daily functioning are often what brings someone into the provider’s office. Additionally, symptoms such as irritability, agitation, and insomnia, which are common in mixed states, may be misattributed to anxiety or unipolar depression, further contributing to underrecognition.
These realities are part of what make BD-I so complex to accurately diagnose. As clinicians, we have the responsibility to thoroughly assess our patients’ medical histories, doing thoughtful dives into their relevant experiences.
Like any serious mental illness, BD-I rarely reveals itself through one symptom or moment. Over time, sleep patterns, periods of unusually high energy, impulsive decisions, changes in productivity, or irritability are details that provide clues to differentiate BD-I from other mood conditions. Because a bipolar diagnosis relies heavily on a patient’s history and sequential symptoms, these nuances can easily be missed without careful questioning. A longitudinal understanding of symptoms, rather than a single cross-sectional view, is often critical in making an accurate diagnosis.
Why accurate diagnosis matters
A correct diagnosis underpins mental health care. Relative to BD-I, when the presence of mania alone or mixed features is not recognised, it can complicate treatment. Treating what is actually BD-I as straightforward depression can delay desired outcomes because the two conditions require distinct approaches. Identifying how symptoms manifest and cycle for each person is an important part of determining the most appropriate therapeutic strategy, including medication.
The clinical practice of mental health care rarely, if ever, comes down to a single variable. It requires listening, being thorough, and understanding the person in front of you. As I often tell trainees, you have to examine all the variables that make that individual who they are, including their biological makeup and psychosocial factors.
This is when careful evaluation and patient education become essential, because early awareness and intervention are beneficial. Understanding how mood states evolve over time, and that there can be distinct phases preceding diagnosis as well as shifts during a person’s lifetime, both internally and externally influenced, enables us to tailor treatment recommendations. When clinicians efficiently identify the involvement of mixed features, that informs strategies to address both the depressive and activating components of the illness.
Healthcare providers have a range of approved medications to choose from for the treatment of bipolar disorder, and will work with the patient to select the optimal pathway. I appreciate having multiple evidence-based options and innovative molecules and formulations that allow for more individualised care based on a patient’s symptom pattern and history.
Part of thorough treatment planning is working with patients and their support systems to understand what to watch for after beginning or changing a medication. Encouraging patients and families to pay attention to patterns such as reduced need for sleep, racing thoughts, bursts of energy, or sudden irritability, especially when they occur alongside depressive symptoms, can help guide more productive conversations with the entire care team. Often, the people closest to the patient are the first to notice changes in mood or behaviour, and those observations can be valuable.
If we begin with the understanding that BD-I is a medical condition, we can then appreciate that it, like many illnesses, doesn’t act or appear the same in each case. Importantly, there are effective treatments available, and even indicated for certain complex presentations such as mixed episodes. World Bipolar Day each year provides an opportunity to continue normalising conversations about these experiences so that patients are empowered to seek help and healthcare providers feel more confident identifying the full spectrum of BD-I symptoms earlier.
About the author
Roger Rivera is board certified as a family nurse practitioner (FNP) and psychiatric–mental health nurse practitioner (PMHNP). His areas of expertise include psychiatry, family medicine, critical care, emergency medicine, and trauma surgery. He holds a Nurse Educator Certification from the University of Florida and is enthused with treating as well as teaching the art and science of integrative psychiatric care, especially with the experience incurred in the various specialties.
