IEvery person has in principle a predisposition to fall ill with a bipolar disorder. Why exactly an individual is ill is as yet still unclear. One assumes various causes, which often develop their effect in the respective combination and can contribute to the onset of the disorder. Listed below is a general overview of the most important suspected causes.
The bipolar disorder is not a genetic disorder in the classical sense, even though a great genetic component exists. Not a single gene is the cause, but several genes, which for example are responsible for the regulation of messenger substances (so-called neurotransmitters). The probability of being ill with a bipolar disorder is increased by about seven times compared with the general population for first-degree relatives (i.e. brother, sister etc.) of bipolar relatives. Parental styles or traumatic life experiences can however also be involved. Evidence of an increased risk of bipolar mood disorders could also be furnished in adoption studies. If identical twins were investigated, which consequently have the same genetic predispositions and one twin had a bipolar mood disorder the other twin also had this in 60% to 80% of cases. Conversely, it could be said that 40% of the twins were healthy or not bipolar despite the same genetic predisposition. Many different factors obviously play a role therefore. Moreover, it gives cause for serious concern that the genes also do not have a "deterministic" (=unilaterally defining) effect, but e.g. can be “awoken” through stress factors. Environmental and genetic factors thus act in correlation.
Neurotransmitters are messenger substances in the brain which render information between the individual nerve cells. Expressed simply, the messenger substances noradrenalin, serotonin and dopamine are mainly affected. In the case of depressions (roughly speaking) a reduced concentration, in manias an increased concentration of these neurotransmitters is suspected. Many drugs start their mode of action based on this model. In the nerve cell various types of processes are initiated by the neurotransmitters, which in turn can be disturbed in their sequence. It is suspected that each phase of the disorder “blazes” certain “trails” in the nerve cells, which favours the onset of new episodes. Correspondingly, the prevention of new phases is accorded an important significance in the treatment of the bipolar disorder. All in all, however, complex processes are responsible for the onset of the individual episodes with their different characteristics. You can imagine the interplay of these processes as a mobile made of thousands of individual parts – one carries out a change in one of the parts the other parts move and are changed. This shows that a therapy sometimes passes through many attempts until an effective treatment is found.
Stress can take very different forms. What appears positiv for one person such as an upcoming birthday can be perceived as “stressful” by another as a result of the required ability to adapt or the feeling of excessive demands. Shift work, separations, family or financial worries etc. can favour the onset of a disorder in their interaction with an individually determined vulnerability. Constant stress in turn can promote the onset of new illness episodes.
Many persons afflicted report that in the event of a longer duration of illness the episodes are often provoked by stress, which was perceived as insignificant in former times; the disorder has therefore developed a certain momentum in its course.
Lack of sleep and an irregular day-night rhythm can likewise favour the onset of new episodes, as can alcohol and drug consumption.
Every person has a different vulnerability or susceptibility to fall ill with a psychic disorder. This susceptibility exists in everybody; however it is increased if various vulnerability factors come together. The increased susceptibility can be caused by a large number of various factors, e.g. by a genetic burden, temperamental factors, traumatic life events etc. Stressful phases of life are e.g. puberty, school leaving examination, marriage, loss of a close relative or friend, pregnancy or critical life events. If these burdens coincide with a vulnerability and insufficient coping mechanisms in the case of a corresponding tendency a manic or depressive episode can occur.
The model of the “biological scar” states that emotional strains pave the way for certain neuronal connections and neglect others. In this connection, earlier experiences with stress play a great role. Stress in later years of life is perceived under circumstances more sensitively than formerly and the track is deeper due to earlier experienced stress. Decisive life experiences can therefore leave behind “biological scars” and an increased vulnerability. The cerebral metabolism is influenced in such a way that it reacts more sensitively than usual to subsequent events. One’s own psyche becomes more sensitive to stressful events.
a) Person with limited vulnerability only becomes ill at high stress intensity
b) Person with high vulnerability already becomes ill at a lower stress level
c) With the same vulnerability the person can cope with higher stress intensity without falling ill at a higher protective level.
It is not sufficient for a comprehensive understanding of the bipolar disorders to fall back exclusively on biological explanatory models but one must also see the person in his / her various forms to understand the disorder in this connection.
Often, depressive people have deeply internalized the predominant social norms. In manias these norms are sometimes called into question in a provocative manner, mostly however without these really being abandoned.
The similarities of both phases include changed time perception, feelings of emptiness and senselessness. Both phases can mutually cause and strengthen one another in a kind of wave movement: anyone who has fully savoured a mania can bring him / herself into such a comprehensive state of exhaustion that the depression follows almost by itself and a depression can be perceived so deeply that a flight into mania remains as the only way out.
Depressions and manias can also be understood as an expression of insufficient feelings of self-worth. The sensitivity to disorders can be increased through previous experiences. The depression leads to a devil’s circle of self-deprecation. But in the listed spirits of mania as well the feeling of self-worth is not really approached; the abasement occurs delayed and is conveyed through the negative reactions of the surroundings and the inevitable physical exhaustion.
Both states, mania and depression, not only mean disturbance, but at the same time also - momentarily and insufficiently - a stabilization of the inner emotional balance. The mania provides relief by helping fend off anxiety. The deep depression protects by being able to tie-up desperation and opposing the implementation of suicidal intentions with an inner paralysis.