Bipolar depression is a mood disorder characterised by cycling bouts of major depression and mania. These two conditions represent opposite ends of the spectrum in terms of mood disorders, with major depression causing sadness, lack of energy, loss of energy, suicidal thoughts, loss of sex drive, tiredness, hopelessness and pessimism; and mania causing restlessness, racing thoughts, extreme happiness, increased sex drive, enhanced creativity and delusions of grandeur.

It is a common misconception with bipolar depression that these two extreme moods are ‘good’ and ‘bad’ respectively; however, though more pleasant for the sufferer, mania can cause just as many problems as major depression. While the increased mood and creativity may seem like good qualities, soon manic individuals can lose control and be dangerous to themselves and others. Severe cases of mania can cause the individual to become aggressive or even violent (mania actually means extreme rage), begin to hallucinate and believe they have special powers, gamble and spend money, flirt inappropriately, drive dangerously, develop addictions and become more selfish. It can also be incredibly tiring for both the sufferer and those living with them.

The exact symptoms of bipolar depression will vary from individual to individual and different patients may experience the symptoms to varying degrees. Usually the patient will experience manic and depressive episodes, punctuated by spells of relative ‘normal’ mood. In most cases the depression will last for much longer periods of time than the mania. A fairly average pattern would be for an individual to suffer two weeks of mania and five months of depression. Periods of ‘normal’ mood could last three to five months. However it is possible for any of these episodes to last shorter or longer, in some cases periods of normality can last as long as two years making bipolar depression difficult to diagnose.

In some cases the symptoms of the depression and mania may be less pronounced. ‘Mild’ mania is known as ‘hypomania’ and can actually be a beneficial state leading to high performance and achievement (many geniuses and prodigies are thought to have suffered from mania, including Vincent Van Gogh), mild depression meanwhile is known as dysthymia. Meanwhile a ‘mixed state’ (also referred to as dysphoric mania, agitated depression, or a mixed episode) describes an episode that sees both symptoms of mania and depression. For example this might consist of high energy and racing thoughts with sadness or hopelessness, or tiredness and lack of sex drive mixed with extreme optimism.

The severity and regularity of these episodes is used to diagnose the form of bipolar depression. ‘Cyclothymia’ is bipolar depression in which the patient cycles rapidly from hypomania to dysthymic mood without bouts of normality. Meanwhile ‘rapid cycle bipolar depression’ is the same rapid switching but featuring major depression and full-blown mania. In cases where the individual suffers more depression than mania, the condition is diagnosed as type 2 bipolar depression. Type 1 sees both episodes taking up roughly equal time, though this is less common. Different forms and severities of bipolar disorder represent different scores on a depressive ‘spectrum’. A ‘spectrum’ disorder can describe any mood disorder.

It is thought that roughly 0.8% of the Western population experience at least one manic episode in their life, and 0.5% a hypomanic episode. Overall 6.4% of the population are estimated to suffer from bipolar depression. The causes of bipolar disorder are not fully understood and most likely vary between cases. Twin studies suggest a genetic element, though are conceptually limited (small sample sizes, lack of separated twins, environmental factors, and the recent discovery that even monozygotic twins do not have 100% identical DNA make these studies difficult). However, findings still suggest that bipolar depression is roughly 30% genetic. Various genes have also been isolated and thought to be responsible for the disorder, though none conclusively and the practice of finding genes for specific personality traits and disorders remains controversial.

Other theories point to environmental factors as playing a larger role in the development of bipolar depression. It is possible that these interact with a genetic susceptibility to trigger the onset of the condition. Childhood trauma for example is correlated with bipolar disorder such as abuse or loss. Studies looking into psychological patterns surrounding bipolar depression have demonstrated periods of depression and anxiety leading up to cases of bipolar disorder. Later elements of mania, such as racing thoughts, may develop. An individual may find they then take less notice of outside events, being caught up in their own thoughts. This can be contributed to by patients holding faulty beliefs and perceptions of themselves and their social world, such as feeling high feelings of high expectations and pressure. Criticisms from friends and loved ones can worsen this situation creating a vicious cycle. Some theories suggest that individuals then become gradually more sensitive to emotional triggers, until their mood begins to drastically change with no obvious trigger. Some individuals also demonstrate frontal-temporal and subcortical difficulties relating to planning, attention and emotional regulation. This concurs with other suggestions that despite its seeming random nature, the progression of the mood cycles is dictated by a complicated interplay of internal and external factors.

Bipolar depression has also been associated with melatonin activity and other imbalances in neurotransmitters, as is common with mood disorders in general (it is a point of contention in psychology as to whether faulty neurotransmitters result in mood disorders, or whether faulty moods result in unusual production of neurotransmitters). There are therefore many pharmacological treatments for the condition, the most widely used being mood stabilisers such as lithium carbonate or lamotrigine. Antipsychotics such as quetiapine or olanzapine can be used to treat acute manic episodes, however antidepressants are not largely used as they have been shown to worsen the cycling of episodes.

Mack LeMouse

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