Understanding Depression: Causes, Symptoms and Treatment, Page 1

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Consulting Clinical Psychologist Dr Joseph M. Carver, PhD, offers this look at depression from the standpoint of causes, brain chemistry, and treatment.


Depression is perhaps the most common of all mental health problems, currently felt to affect one in every four adults to some degree. Depression is a problem with mood/feeling in which the mood is described as sad, feeling down in the dumps, being blue, or feeling low. While the depressed mood is present, evidence is also present which reflects the neurochemical or “brain chemistry” aspects of depression with the depressed individual experiencing poor concentration/attention, loss of energy, accelerated thought/worry, sleep/appetite disturbance, and other physical manifestations. When this diagnosis is present, the individual will exhibit at least five of the following symptoms during the depressive periods:

  • Depressed mood, most of the day or every day
  • Markedly diminished interest in all or almost all activities
  • Significant weight loss or gain or appetite disturbance
  • Insomnia or excessive sleeping
  • Psychomotor agitation or retardation (restlessness)
  • Low energy level or chronic tiredness
  • Feelings of inadequacy, loss of self-esteem, and/or self-deprecation
  • Decreased attention, concentration, or ability to think clearly
  • Recurrent thoughts of death or suicide, an expressed desire to be dead

Causes of Depression

Depression can occur under many circumstances but most commonly is present in these two situations:

Sudden Severe Loss
In this situation, the individual has experienced a sudden, perhaps surprising severe loss. This loss may be the death of a loved one, loss of a job, loss of friendship, or other grief process. In this type of depression, the patient can clearly identify what is creating the depressed mood.
Long-term High Stress Level
In this situation, the patient is depressed but can’t quite put their finger on the cause, the “I’m depressed but I don’t know why” condition. Imagine running a video tape of your life, reviewing the past 18 months. Look at the stress you’ve been under, the amount of responsibility, the number of pressures, and the number of hassles. In actual clinical practice, this cause of depression is seen more often than sudden loss. This type of depression creeps up on you. When this type of depression is experienced, the patient offers comments such as: “I don’t know what’s wrong!” “I don’t know how I feel.” “My feelings are numb.”

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Brain Chemistry and Depression

The human brain operates, much like your automobile, on fluids called neurotransmitters. Just as your automobile has brake fluid, antifreeze, transmission fluid, and oil – your brain runs on these neurotransmitters. Some give us energy, like those related to adrenalin, some control body movements (“dopamine” as an example), and some control mood.

The brain neurotransmitter often associated with depression is called Serotonin. Serotonin is the brain’s “oil”, a rather slow-acting neurotransmitter that is associated with sleep, appetite, energy, alertness, and mood – just to name a few. Using the automobile as an example, if we drive our car to California at a speed of 120 mile per hour, running the engine hot for a long time, it would obviously use more oil. As long as we provided gas, however, it would continue to run. Now suppose in our trip that for every two quarts of oil we burn, we only replace one quart. By the time we reached California we’d be several quarts low and our engine would be obviously overworked and overheated.

During long-term high stress, the brain burns its oil, Serotonin, at a higher rate. The bottom line in depression and stress: The brain burns up more Serotonin than it can replace! In the end result, after many months of severe stress, the brain is using Serotonin faster than it can create/replace it. Your neurochemical level of Serotonin drops and you become depressed.

You’ll know your Serotonin level is low (and depression is here) by the following symptoms:

  • Most depressed folks experience early morning awakening, usually around 4:00 am (farmers are exempted). Serotonin, you see, controls our sleep cycle.
  • Concentration and attention will drop. Depressed children/students will experience a drop in grades. You’ll start putting odd things in the refrigerator (a bowling ball is the office record!), forget why you went to the grocery, and become very forgetful and scatterbrained at work/home.
  • You’ll lose physical energy. You can sleep for ten hours and you’ll still be bone tired. You will cry at the drop of a hat – driving down the highway, doing dishes, sitting at work, etc.
  • Sexual interest, appetite, and general interest will rapidly drop. You will stop answering the phone, stop visiting friends/relatives, and pull the blinds.
  • Most dangerous – your mind speed will increase. Your mind will race at what seems like 200 miles per hour. Depressed people often tell their doctor “I can’t get my mind to stop!” The minute you wake up in the morning – it will start up. Your brain will then turn against you. It will reach in your memory and pull out every bad memory it can find – abuse as a child, failed relationships, etc. – anything to make you feel bad and especially guilty. You will be tortured by your own thoughts.
  • As your mind speed picks up, the “garbage truck” will arrive. While the brain is already torturing you with the past, it will create/invent new ideas/thoughts to torture you. In every case of depression, if the depression stays long enough, you will receive the same “garbage” thoughts from your mind. You will be told:
    • you are a burden to your family/friends
    • you have failed/disappointed your family
    • no one really cares about you
    • your children would be better raised by someone else
    • your family would be better off without you
    • your spouse would be better off without you
    • you are going crazy and there’s no hope
    • it would be better if you weren’t around
    • you would be better off dead
    • you should probably kill yourself

    If you’re depressed – then you already know about the garbage truck. It’s almost impossible to explain this part, and the excessive mind speed, to someone who has never been seriously depressed. If your depression goes untreated, this constant “garbage” will totally destroy your self-confidence. Try as you may, you will be unable to control this part of depression.

  • As part of the “garbage truck”, your mind will try to make you as uncomfortable as possible. You may be flooded with thoughts of violence (against yourself and others), you’ll think you are condemned by God, or you’ll think you deserve this condition for some reason. Your garbage will also tell you that if you seek professional help (physician, psychologist, psychiatrist, etc.) that you’ll be committed to an institution forever.
  • When depressed, your brain begins running a mental “video tape” of your worst hits/experiences. If married, a mental tape of the marriage is played daily, only focusing on the worst experiences. If you are young, you will suddenly become preoccupied with your upbringing, who got the best gym shoes, the favorite child, the car you never received. Frequent if not constant thoughts and preoccupations about past problems and issues is a common sign of depression.

In short, depression is a neurochemical reaction to severe and prolonged stress, either suddenly surfacing or gradually creeping up on you over a period of many months. The treatment for this dark cloud is much easier than you think.

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