Medical Causes of Depression
As we have seen, depression is not primarily a physical disorder, although it is often described as a 'disease'. (If you have completed the rest of the Learning Path so far, you must excuse us for repetition, it's essential that this idea is dealt with, otherwise as a sufferer you can feel helpless, and assume that drugs are the only answer.)
"Depression, we are saying, is not a disease; it is a natural response to certain types of emotional introspection that result in excessive dreaming." - Human Givens, 2003, J. Griffin & I. Tyrrell
Overcoming depression is made much harder by the many half truths that are commonly aired, on the news, in magazines, or by well-meaning friends. These often make it seem inevitable you'll get depression, or that once you suffer from depression you'll have it for life.
It's essential to understand that depression is much more than simply a disease or a chemical imbalance. The more we understand about the cycle of depression, that affects our mind and body, the better prepared we are to treat it.
Throwing some light on some of commonly claimed 'medical' causes of depression, gives us a better understanding of depression, and therefore a better chance of overcoming it.
Depression as a disease
Depression can not be said to be a disease, because it is not primarily a biological disorder - that is, the root cause of the symptoms are not usually physical. How do we know? Well, here's one way:
People born since 1945 are 10 times more likely to suffer from depression than those born before.
That is an astounding figure, and it cannot be explained away by people going to their doctor more, or depression being diagnosed more easily, as these were taken into account in the study.
Human biology doesn't change that quickly.
What it does show clearly is that most depression is non-biological. Depression has biological effects, but studies now show that less than 10% of depression is biologically caused.
The most widely accepted explanation for this sort of phenomenon is that society has changed. Over the past 5 decades, there has been:
- a breakdown in the extended family
- a dispersal of communities
- an increased focus on material wealth
- an overwhelming prevalence of news media
- and an increase in focus on 'the self'.
All of which, and more besides, add up to a potent recipe for depression.
Changes to levels of neurochemicals
Clinical Depression is often said to be caused by a chemical imbalance in the brain, and this is what most drug treatments are based on. Certainly in many cases, there is a reduction in the amount of certain neurotransmitters found (monoamines such as serotonin and norepinephrine) in depressed people.
However, low serotonin levels are simply another symtom of depression, not a cause. The more negative introspection you carry out, and the fewer pleasure-giving activities you participate in, the lower your serotonin levels become.
"Regarding depression as "just" a chemical imbalance wildly misconstrues the disorder." - Psychology Today, March 1999
Drug therapies that work on this imbalance lift depression completely in a third of those who take them and partially in another third. For a third of people, antidepressants don't work at all, and many who do get positive results stop taking them because the side effects are worse than the depression symptoms they are supposed to be treating.
Antidepressants are also much worse at preventing relapse than appropriate psychotherapy (which is obvious, when you consider they are treating a symptom, not the cause of depression.) (1, 2)
Depression can lead to chemical changes in the brain, which return to normal once your depression lifts.
Also, we are fully aware that clinical depression is far more than a prolonged sadness, or period of grieving. Yet these chemical imbalances can be found on occasion in all of these situations.
One 'medical' cause of depression often given is the overproduction of stress hormones.
The hormonal imbalances related to depression are to do with our natural reactions to stress, and stress and depression are certainly linked. But does this hormonal imbalance actually cause depression?
It is true that depressed people often have increased levels of stress hormones in their bloodstream (3), but again, this is a symptom, not a cause.
When you ruminate, or introspect in a negative way, you create emotional arousal that causes the release of stress hormones. That night, in REM (dream sleep), you become emotionally aroused again as dreaming 'flushes out' the emotional arousal from your brain.
That is why depressed people have higher levels of stress hormones, and also why you can wake up feeling exhausted. More on this later.
How can stress cause depression?
Although stress is a fairly "modern" concept in terms of our biology, the body deals with stress by viewing it as a traditional threat, for example being attacked.
To deal with stress, the body's natural "flight or fight" reactions kick in. Namely:
- shutting down nonessential or distracting activities
- enhancing delivery of "fuel" to the main muscles
- suppressing appetite for food and sex
- heightens alertness
- increasing levels of stress hormones such as adrenaline and cortisol
Obviously this state is not healthy for prolonged periods of time.
The actual link connecting depression and stress concerns our thinking styles, namely the "All or Nothing" thinking our mind uses when it feels we feel threatened.
When you are stressed, your brain works differently. You are more likely to resort to 'All or Nothing' thinking, which causes catastrophising, and difficulties in solving complex problems.
In turn, this creates more arousal, or stress, and so continues the 'loop', increasing the amount you dream, and so exhausting you. This has an additional effect in the way it changes your sleep patterns, as you will see later in the Learning Path.
As we continue to discuss this, remember that statistics only give a general picture. Your own case is totally individual and you should not rule out any line of treatment. For now, your best weapon against depression is knowledge.
Next article: Medical Causes of Depression (cont.)
Next in the Learning Path, more on the myths surrounding the causes of depression...
- Teasdale, J. D. et al. (2000) Prevention of relapse/recurrence in major clinical depression by mindfulness-based cognitive therapy. Journal of Consulting and Clinical Psychology, 68, 4, 615–23.
- Psychotherapy Versus Medication for Depression: Challenging the Conventional Wisdom With Data – David O. Antonuccio and William G. Danton, University of Nevada School
- Nemeroff, C. B. (1998) The neurobiology of depression. Scientific American, 278, 6, 28–35.