What is Bipolar Disorder?
It an episodic circadian rhythm disorder. Oh--and there is a mood component.
Last week, I was invited to speak to around 100 mental health professionals (and some non-professionals, also) in Nigeria, as part of the Gracehill Hospital and Partners Quarterly Virtual Lecture Series. Translating my enthusiasm for—let’s be honest, expensive—hard-to-globally-scale 3-Tesla medical-imaging-innovations to an audience in the global south was a challenge. The audio of my talk is included below:
How Can We Treat Bipolar Disorder in the Global South?
I was invited, thanks to the magnificent and only-ever-positive internet, to give a lecture to colleagues in Nigeria. I’m kidding, a little—the internet can be rough. Ask a comment section of a YouTube video! However, it is also a technology that has brought the world closer together. One of those less absurd corners of the
Here is one takeaway for the assessment and management of bipolar disorder, anywhere.
The original name for bipolar disorder was manic depressive illness. I prefer this name. The core of the illness, whatever we call it, is its episodic nature.
Sometimes, and not other times.
In most cases, again.
These discrete episodes of changes in mood, energy, attention, activity, sleep, irritability, and even a loss of grounding in reality are the hallmark of the disorder. If you're a clinician, it's worth taking an interest in the time course of the symptoms being presented to you. If you're lucky enough to see someone in the midst of an episode, at least that episode is often obvious.
But there's a built-in problem with bipolar disorder, which is that some of the episodes are depressive and look just like any other depression. Other episodes are manic, or mixed, and don't look like depression. Severe manic can have psychosis that is so profound. It's indistinguishable from different illnesses, like schizophrenia, or even acute intoxication with substances. My favorite book on this topic is “Just Like Someone Without Mental Illness, Only More So” (Amazon affiliate link).
Thus, patients with bipolar disorder are well served by clinicians who are stalwart. Stick around long enough to see the next episode—that helps definitively make the diagnosis!
A non-episodic illness is not bipolar disorder. Someone with bipolar mania isn’t “manic all the time.” Similarly, although the episodes of depression can be prolonged, they tend to be shorter and more abrupt than those in unipolar depression:
The median time to recovery for bipolar depression was 2.0 months (95%CI: 0.9–3.1), that for unipolar depression 3.0 (2.5–3.6)1
One of the issues with the episodic nature of bipolar disorder is that, despite the episodicity being crucial, it has not been treated as a measurable construct in the literature:
it seems evident that that NoE may best be treated as a fuzzy construct (rather than precise figure), with yet to be defined overlaps with clinical variables such as age at onset and severity. Attempts to measure this construct have varied in comprehensiveness and structure.
This is despite the crucial nature of counting episodes:
Multiple studies have linked Number of Episodes with important clinical factors, including relapse, functioning, cognitive impairment and the effectiveness of both pharmacological and psychosocial interventions2
Part of the issue, for scientists (like your author), is that the disorder itself impairs the encoding of memory among those suffering regarding those very episodes:
Patients were selectively impaired in recollecting episodic details of events encoded during mania but not depression or euthymia. No significant differences emerged between patients and controls for recollection of non-episodic details, regardless of mood state.3
Thus, a plausible reason researchers can’t count the episodes well is that if you ask the person who experienced them, they might remember them poorly! In a fascinating side note, it’s also more common for the perspective of the memories to be different (in perspective) from what we would expect:
Patients with bipolar disorder were also more likely than matched controls to recall memories from an observer perspective.
There are even (with all caveats about small sample size imaging studies aside) changes on brain imaging of those bipolar brains trying to recall things:
Patients with BD remembered less well than controls which shapes they had seen and had lower activation levels during the encoding stage of the task in the anterior cingulate gyrus, the precuneus/cuneus bilaterally, and the left lingual gyrus, and higher activation levels during the retrieval stage in the left temporo-parietal junction.4
One of the more crucial episodic events in all out lives is the pattern of days and nights. This circadian rhythm also plays a key role in the lives of those with bipolar disorder. Bipolar illness is entangled with circadian rhythms. If you follow people over time, for individuals with bipolar disorder, it is likely that their mood episodes “sync up” with the rhythms of the Earth. This is dependent on where on the earth they happen to live—in parts of the world with pronounced seasonal changes, we see synchronized mood episodes! I’ve written about this circadian rhythm tie-in before:
Sleeping regularly is crucial and healthy. We have data backing this up:
Shorter Total Sleep Time was associated with increased mania severity, and greater Sleep Variability was associated with increased mania and depression severity.5
As a piece of advice, I often give: wake up at the same time every day. Anchoring wake-up time reduces chaos over time in sleep cycles and promotes a healthier life in those with bipolar disorder.
In summary, bipolar disorder is episodic. Those episodes define the disorder, and they encompass more than just mood. They encompass memory, sleep, biology, and cognition, and may also predict the course of illness and impairment.
For excellent care of bipolar disorder, consider Radial. It is the company of which I am the Chief Medical Officer, and we are providing care across 18 states, including running clinical trials, including those with bipolar disorder.
Furukawa, T. A., Konno, W., Morinobu, S., Harai, H., Kitamura, T., & Takahashi, K. (2000). Course and outcome of depressive episodes: comparison between bipolar, unipolar and subthreshold depression. Psychiatry research, 96(3), 211-220.
Tremain, H., Fletcher, K., & Murray, G. (2020). Number of episodes in bipolar disorder: The case for more thoughtful conceptualization and measurement. Bipolar Disorders, 22(3), 231-244.
King, M. J., MacDougall, A. G., Ferris, S., Herdman, K. A., Bielak, T., Smith, J. R., ... & McKinnon, M. C. (2013). Impaired episodic memory for events encoded during mania in patients with bipolar disorder. Psychiatry research, 205(3), 213-219.
Oertel‐Knöchel, V., Reinke, B., Feddern, R., Knake, A., Knöchel, C., Prvulovic, D., ... & Linden, D. E. (2014). Episodic memory impairments in bipolar disorder are associated with functional and structural brain changes. Bipolar disorders, 16(8), 830-845
Gruber, J., Miklowitz, D. J., Harvey, A. G., Frank, E., Kupfer, D., Thase, M. E., ... & Ketter, T. A. (2011). Sleep matters: sleep functioning and course of illness in bipolar disorder. Journal of affective disorders, 134(1-3), 416-420.