The question of why
If you search the literature on depressive illnesses for causes and developmental theories, you will find a great many of them. However, very few of them can explain the actual development of depression on their own.
Just as human behavior is multi-determined, i.e. always attributable to several factors, the development of depression cannot be attributed to a single cause. Rather, the complex interaction of individual risk factors (= vulnerability factors) and current psychosocial triggers plays a central role.
On the following page you will find a selection of possible risk factors and psychosocial triggers as well as selected developmental models.
Risk factors and psychosocial triggers
- Genetic predisposition/heritability: if family members, especially first-degree relatives, suffer from a depressive disorder, the risk of developing the disorder yourself is also increased
- Hormonal changes, e.g. during puberty, menopause or pregnancy/birth
- Physical risk factors: e.g. metabolic disorders, obesity, infections, chronic illnesses, hypothyroidism, chronic pain
- Female gender: women are more frequently diagnosed with a depressive disorder
- Belonging to an ethnic minority
- Low socio-economic status
- (Early childhood) traumatic experiences: emotional and physical abuse, neglect, violence, experiences of loss in childhood, parental separation
- Social isolation
- Pre-existing mental illnesses or illnesses that a person already suffered from in childhood and adolescence
- Certain personality styles/personality traits: e.g. neuroticism, low self-esteem
- Stress-triggering, stressful life events: e.g. transition to a new phase of life (e.g. studies), separation, death of a loved one, accident, serious illness, financial worries, time pressure during studies, increased workload, experience of loneliness
- Lifestyle factors: unhealthy diet, smoking, lack of exercise
- Pro-depressant medication (e.g. the contraceptive pill) or addiction and withdrawal from addictive substances (e.g. alcohol, cocaine, cannabis)
The bio-psycho-social development model
The bio-psycho-social development model is often used to explain the development of mental disorders, including depression. It combines factors from the biological, psychological and social spheres, which interact unfavorably and can thus promote the development of a depressive disorder as a whole. The following is an example:
BUT: Just because you may have certain risk factors and at the same time be confronted with certain life demands, this does not necessarily mean that depression or another mental illness will always develop! These unfavorable combinations of risk factors and demands merely increase the likelihood of this. Conversely, a person who does not have a family history, for example, can also develop a mental disorder. There does not necessarily always have to be a triggering event.
There are also individual protective factors that can have a protective effect on mental health. Protective factors or resources include all conditions, people or things that can strengthen our resilience, i.e. our mental immune system, and enable us to cope better with mental crises. These include, for example, good stress management, structured time planning, strong interpersonal relationships, good problem-solving skills, self-confidence, good self-care, a healthy diet and exercise.
Remember!
Regardless of which developmental model is considered, it is clear that depression always arises and is maintained by a complex interplay of various factors. What is important to say at this point and should always be borne in mind when dealing with those affected and their relatives:
No person is to blame for suffering from depression (or any other mental disorder)! We are often socially conditioned to blame ourselves for certain things. In some cases this is justified, but definitely not when it comes to a mental disorder! At this point, it is rather counterproductive to ask who is to blame.
It can affect anyone! As described above, there are certain factors that favor the development of a depressive disorder. Nevertheless, people who have a lot of money and possessions and seem to lead a "perfect" life can also fall ill.
And very important: even if an affected person seems to have all the possible risk factors, has already experienced the worst things and the situation seems hopeless, there are always ways and means of counteracting it! It is highly likely that you will not see these yourself, as depression often only gives you a very limited, negative view of things. Nevertheless, it is worth continuing to look for them with support.
The vulnerability-stress model
In addition to the bio-psycho-social development model, there is also the vulnerability-stress model (or diathesis-stress model), which is particularly useful as a visual explanatory aid. Vulnerability describes a person's vulnerability or susceptibility to developing a mental crisis or ultimately a mental disorder and varies from person to person.
These include, for example, unfavorable social living and developmental conditions, unfavorable (learned) characteristics such as excessive anxiety, female gender, the lack of an intimate, emotionally positive and supportive social relationship, and low self-esteem. However, these factors alone do not lead to the onset of depression. Only in interaction with certain demands/stressors can they contribute to it. Our vulnerability factors, which we all have, can have a significant impact on how we deal with the demands of our environment. Furthermore, the way in which a challenge or stress event is defined also plays a major role. This can be a traumatic life event (e.g. the death of a loved one) or everyday stress (e.g. at work).
If you imagine a vessel, e.g. a barrel, the vulnerability factors ensure that it is already filled to a certain point. As the degree of vulnerability is very individual, each barrel is filled to a different level. Additional demands and stressors contribute to the level rising further. Of course, every barrel also has a tap where liquid can be drained. In our model, the tap can be equated with the protective factors described above and the coping mechanisms. Coping mechanisms describe the set of all action skills that enable a person to cope with demands and stress flexibly, efficiently and across different situations. However, if I have fewer protective factors, resources and coping mechanisms, i.e. I am less able to cope with the demands dripping or rushing into my barrel, it can happen that the barrel overflows and I experience a mental crisis, e.g. in the form of a depressive episode. The following illustration shows the "barrels" of three different people, all of whom have different levels of vulnerability and resources, which leads to the barrel filling up with further stress at different rates.
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