Lesson Two - The Difference between Sadness and Depression
Biological Causes of Depression
There are three main biological causes of depression. Remember that this list is not exhaustive or guaranteed to be one of the causes for everyone with depression.
The frontal lobe of your brain is the part of your brain that is right behind your forehead. There is evidence that a less active frontal lobe will put a person at a higher risk of depression. However, it is not known if depression causes
lower activity in the frontal lobe or if low activity causes depression.
It has also been shown that the hippocampus (a part of the brain that is in charge of long-term memory and recollecting memories, among other things) was, on average, smaller when someone had depression, and got subsequently smaller with each session of depression.
It has also been suggested by researchers that people with depression do not develop new neurons (a special type of cell in the brain that “talks” to other parts of the brain using electrical impulses) as quickly as those people who do not have depression.
The amygdala is the “emotion” part of the brain, and has been shown to have increased activity in those that are depressed or even sad. Interestingly, the increased activity lasts even after the sadness or depression has passed, making the person more sensitive to emotions.
It has also been shown that the hippocampus (a part of the brain that is in charge of long-term memory and recollecting memories, among other things) was, on average, smaller when someone had depression, and got subsequently smaller with each session of depression.
It has also been suggested by researchers that people with depression do not develop new neurons (a special type of cell in the brain that “talks” to other parts of the brain using electrical impulses) as quickly as those people who do not have depression.
The amygdala is the “emotion” part of the brain, and has been shown to have increased activity in those that are depressed or even sad. Interestingly, the increased activity lasts even after the sadness or depression has passed, making the person more sensitive to emotions.
A common misconception is that depression is caused simply by a chemical imbalance in the brain. While there might be some imbalances, this statement oversimplifies depression and downplays the effectiveness of psychotherapy. Depression
is associated with lower levels of certain chemicals (neurotransmitters) in the brain, mainly serotonin and noradrenaline. This has only been shown to be an association and not a cause.
Sometimes medical conditions can put a person at a higher risk of developing depression. Most of the time, these medical conditions are chronic or long-lasting. The stress of coping with a serious illness can contribute to depression. Some examples of
chronic medical conditions that may lead to depression are insomnia, chronic illness or pain, and even attention deficit hyperactivity disorder (ADHD). Here is a list of other major medical issues that have also been linked to depression:
| hypothyroidism | heart disease | degenerative neurological conditions (such as MS, Parkinson's Disease, Alzheimer's Disease, and Huntington's Disease) | strokes |
some nutritional diseases (such as lack of B12) |
| endocrine disorders | immune system diseases (such as lupus) | virus and other infections (such as HIV or hepatitis) | cancer | erectile dysfunction in men |
Personality factors can also play a role in the development of depression. The following is a short list of personality factors that can be possible sources of depression.
People who:
- tend to worry quite a bit
- have a low self-esteem
- are perfectionists
- are quite sensitive to criticism
- are critical of themselves have an overall pessimistic outlook