Bipolar disorder is a complex mental illness that affects about 2% of the population. The most telltale sign of bipolar is the shifting in mood between periods of sickening lows (sadness, hopelessness) to periods of exhilarating highs (elation, high energy), with normal mood in between.

Who gets bipolar disorder?

Bipolar disorder isn’t fussy. It can afflict anybody and like so many mental illnesses, we really don’t know why some people are struck by it and some people aren’t. What we do know is that bipolar has absolutely nothing to do with intelligence, character or personality. It has a physiological basis, but it expresses itself through emotion, behaviour and mood. 

Researchers have identified small variations in a number of genes that are closely connected to an increased risk of developing bipolar disorder. A family history of bipolar seems to be the greatest risk factor, but it’s important to remember that most people who have the family history will never go on to develop the illness.

What does it feel like?

For people with bipolar, the extreme shifts between depression and exhilaration and back to depression are cruel and unpredictable. Bipolar disorder takes people to the greatest highs and plunges them to the most devastating lows. 

In a manic state, the elation and high energy can feel euphoric. Confidence escalates. Limits disappear. Thoughts and ideas race, with a new one beginning before the last one is finished. Speech, behaviours, and actions speed up to keep pace with a mind that is catapulting forward. Energy feels boundless and sleep can feel irrelevant.

Sometimes, people in a manic state can become agitated and irritable, particularly when it feels as though other people can’t keep up, don’t understand them or are trying to dampen their energy. They might love hard and hate just as hard.

People in a less extreme manic episode might function well and be highly productive, working through the night to get things done. The first sign that bipolar disorder might be behind the high productivity are the shifts in mood and activity levels. Often, the person might feel as though nothing is wrong, so it’s not unusual for people close to the person to be the first ones to notice that something isn’t right. 

The manic phase of bipolar can feel unbelievably exhilarating. Inhibitions are stripped right back, and it can feel as though anything is possible. Because of this, people in a manic state might do risky things. They might have reckless sex, overspend, or make impulsive, catastrophic decisions. They might make wild plans that involve huge amounts of money, grand intentions or famous people who will surely understand and applaud their vision. Again, this has nothing to do with intelligence or character. It happens because they are being driven by a mind that is hurtling them forward, convincing them they can do anything, be anything and achieve anything. Their body backs this up by giving them more energy than someone without bipolar might ever get to experience at a single point in a lifetime. 

Then comes the crashing depression. The crash would feel thunderous for anyone, but when the fall is from such an extravagant, lofty height, it’s devastating. The exhilaration and extreme feelings of freedom and possibility are replaced with intense sadness, emptiness, and hopelessness. The high energy crashes. The mind is burnt out and the body is exhausted, and the reality of decisions made during manic phase hit home. The things that usually bring immense joy now bring a dead nothingness. In a depressive state, people can have difficulty concentrating, and they might be forgetful. Extreme hopelessness and sadness can drive suicidal thoughts, and the shame and guilt from the things done during a manic episode might feed the darkness even more. In the darkest times, suicide might feel like the only way out of the pain. 

The presence of bipolar disorder might not always be obvious. Sometimes, the depression and mania can exist together. When this happens, people might have a lot of energy, but at the same time feel intense sadness and hopelessness.

More recently, bipolar disorder has started to be classified as early-stage bipolar or late-stage. The classification isn’t so much about the length of time the person has had the symptoms, but more about the number of episodes and the severity of the symptoms. People with early-stage bipolar disorder have had fewer manic or depressive episodes, whereas those with late-stage bipolar have had more episodes with more severe symptoms.

Some new insights …

One day, those who attach a stigma to mental illness will be seen to have the same level of naivety as those who believed the earth was flat. As we uncover more about the causes and characteristics of certain mental illness, it becomes increasingly clear that mental illnesses have a physiological cause. They are physical illnesses that come with physical symptoms, as well as behavioural, emotional or cognitive ones. Here are some of the things we are learning about bipolar disorder:

1. The architecture of the brain of people with bipolar disorder is different.

   The brains of people with bipolar disorder show typical features that are different to the brains of people without bipolar. First, the brains of people with bipolar have a reduced volume and show evidence of a process in which the brain re-writes the connections between its neurons (brain cells). This is something that normally happens with learning and memory and recovery from brain damage, but in people with bipolar, the process is associated with a loss of neurons and a deterioration in cognitive function.

2. The blood of people with bipolar disorder is different.

   Research has shown that the blood of people with bipolar disorder has some interesting features that are associated with the severity and frequency of mood episodes. Their blood has several markers related to inflammation and oxidative, and lower levels of the protein (BDNF) that supports the growth and survival of neurons, and helps to establish connections between neurons.

3. The bipolar brain has less of a protein that helps it to adapt to stress.

   The brains of people with bipolar disorder have lower levels of a protein (EGR3) that helps the brain to cope with stress and changes in the environment.

4. Lower levels of omega 3 in the blood of people with bipolar disorder.

   Faty acids have a vital role in brain health, the immune system, and the inflammatory system. Research has found that people with bipolar disorder have lower levels an omega-3 fatty acid called EPA in the blood, which is the type that crosses the blood-brain barrier to enter the brain. (Previous research exploring the connection between fatty acids and bipolar has focussed on the levels of fatty acids in cell membranes.) 

5. Cells in a brain with bipolar disorder are more sensitive to stimuli.

   Research recently published in the journal Nature, found that the neurons from people with bipolar are much more sensitive than neurons from people without bipolar disorder. Normally, neurons are stimulated and then they respond. In people with bipolar, the neurons are very quick to respond – they don’t need a lot of stimulation. The energy-producing powerhouses in the cells – the mitochondria – are also more active.

   ‘After a few months, it’s possible that this hyperexcitability becomes too much for the cell to handle and it crashes into a less excitable state … That could signal the shift between the depression and mania that patients experience.’ Rusty Gage, senior researcher and professor, Salk Institute Laboratory of Genetics.

6. The blood of people with bipolar disorder is toxic to the brain.

   Recent research published in the International Journal of Neuropsychopharmacology has found that the differences in the blood of people with bipolar are also associated with changes in the brain of people with bipolar disorder. As part of the research, neurons were exposed to blood from individuals with bipolar or without bipolar. The neurons that were exposed to the bipolar blood showed evidence of a loss of neuron connections when compared to the non-bipolar blood. The difference was only noticed in those with late stage bipolar. The blood from early stage bipolar was similar to the people without bipolar.

   ‘Our results indicate that the blood of BD [bipolar disorder] patients is toxic to brain cells and affects the connectivity ability of neurons. Considering our previous knowledge on the association between mood episodes and blood toxicity, we believe that the more episodes a patient has, the more cellular components are produced that impair the brain’s ability to deal with environmental changes, inflammation and stress.’ Fabio Klamt, lead researcher, Federal University of Rio Grande do Sul.

And finally …

Incredible advances in technology are opening up our capacity to observe and learn about the brain. With this increased knowledge comes great opportunities for new treatments that are more effective and have fewer side effects. Researchers are continually edging closer to finding a way to manage bipolar disorder so that its effects are less intrusive for those who have the disorder, and the ones who love them.