*I got tired of hearing about how exercise reduces symptoms of depression and that the incidence of depression among regular exercisers, so when an opportunity to look at the reverse appeared, I took it. Here is a summary of my research (“lit review”/”background review” for you nit pickers).*

Exercise normalizes the body’s functions. For example, if a person with high blood pressure were to continue on a long-term exercise plan, blood pressure would be reduced. Exercise works the other way, too; a person with very low blood pressure who follows a long-term exercise plan will find their blood pressure rising into the body’s optimum range. Likewise it reduces the effects of insulin resistance (in other words, it increases the body’s sensitivity to existing insulin levels), which is why exercise is often part of the management plan for diabetics.

Exercise has a similar effect on the brain, and therefore, mood. In a normal person, exercise releases endorphins, increases serotonin and norepinephrine levels, and reduce cortisol levels, all of which result in an increase in perceived mood. Unfortunately, such is not always the case with those who suffer from depression. There is a high correlation between patients with major depressive disorder and those with smaller than average hippocampal regions with less neurogenic activity in the region affecting both memory and mood. (Lorenzetti, Allen, Fornito, & Yucel, 2009)

What exercise will do for the depressed client is: reduce cortisol levels and increase endorphins. There are conflicting studies as to whether or not levels of neurotransmitters are changed via exercise; however a recent study involving mice demonstrates that exercise decreases observable depression-type behavior even when tryptophan levels (a precursor and limiting factor for serotonin) were kept low. This indicates that, as with diabetics, exercise may increase the brain’s sensitivity to existing levels of neurotransmitters rather than affecting the concentration of neurotransmitters. (Lee, Ohno, Ohta, & Mikami, 2013) Other studies have shown that there is a lower rate of incidence of depression in regular exercisers. (Strawbridge, Deleger, Roberts, & Kaplan, 2002)

There is a vast pool of literature that tests and retests these conclusions. Few doubt the benefits of exercise on depression. Unfortunately this picture is incomplete. Those who are chronically depressed tend to find it irritating when these and other studies are quoted and we are expected to be motivated. Among other things, we’ve been assured that everything from St. John’s Wort to Prozak will make things better. When treatment after treatment fails, it’s hard to have faith in yet another lifestyle change.

The piece that is missing is how depression affects exercise. More specifically, how do those exhibiting depressive symptoms begin and adhere to an exercise plan.  In terms of everyday language, here are some ways I describe the sensations:

Physical: It’s like being constantly loaded down with weights without the benefits of resistance training.

Emotional: Being ground down by life in all its underwhelming mediocrity.

Spiritual: “This little light of mine”…was blown out long ago, and my heart is bruised beyond healing.

According to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition with text revision (DSM IV-TR), the criteria to diagnose a Major Depression Episode is: 5 of the following symptoms within a single 2-week period, at least one of which must be the first or second symptom on the list:

  1. Depressed most of the day, nearly every day, as indicated by either subjective reports or observation made by others.
  2. Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day.
  3. Significant weight loss (when not dieting) or weight gain.
  4. Insomnia or hypersomnia nearly every day.
  5. Psychomotor agitation or retardation nearly every day.
  6. Fatigue or loss of energy nearly every day.
  7. Feelings of worthlessness or excessive or inappropriate guilt nearly every day.
  8. Diminished ability to think or concentrate, or indecisiveness, nearly every day.
  9. Recurrent thoughts of death or suicide, or recurrent suicidal ideation without a plan, or a suicide attempt or plan.

For Chronic Major Depression, this lasts for months or years at a time.

As with most illnesses, causal factors are rarely as simple as one plus two always equals three. Investigations into the causes of Major Depression typically fall into three categories: biological or physiological, psychological vulnerabilities, and social or environmental. Genetics plays a moderate role in unipolar Major Depression, and is demonstrated through numerous family, twin, and adoption studies. One of the current theories involves a chromosome chain called the serotonin-transport chain. Basically, the longer the chain, the more resistant to depression. The other commonly held theory is the neurotransmitter imbalance theory. There are three neurotransmitters involved in this theory: norepinephrine, dopamine, and serotonin. If one or more of these neurotransmitters is out of balance, then the person is at a higher risk for Major Depression.

The biological side is not the only factor to consider; one must also consider the psychological vulnerabilities. The two primary vulnerabilities are the personality traits of neuroticism and pessimism. Both are stable and heritable (i.e. not mood dependent and can be passed to offspring). Neuroticism, or “negative affectivity,” is defined as a personality trait that involves a temperamental sensitivity to negative stimuli.” Pessimism, or low positive affectivity, is defined as a trait where the person feels unenthusiastic, unenergetic, dull, flat, and bored.

When dealing with others, depressed people display deficits in social skills. They tend to speak more slowly and monotonously, maintain less eye contact, and are poorer than non-depressed people at solving interpersonal problems. As a result, the depressed person “often places others in the position of providing sympathy, support, and care…. Over time, depressive behavior can, and frequently does, elicit negative feelings (sometimes including hostility) and rejection in other people, including strangers, roommates, and spouses.” (Butcher, Hooley, & Mineka, 2007, p. 251)

Few deny the benefits of exercise in moderating the effects of depression; however, the main barrier in gaining these benefits is the depression itself, which creates a downward spiral. Looking at the criteria, four of the criteria apply directly to exercise:

  •                 Markedly diminished interest or pleasure in all, or almost all, activities….
  •                 Fatigue or loss of energy….
  •                 Feelings of worthlessness or excessive, or inappropriate guilt….
  •                 Diminished ability to think or concentrate, or indecisiveness….

If there’s no interest (especially if there’s no pleasure) in exercising, there will be little justification for continuing, or even starting, to exercise. If the person has very little energy, they will be unlikely to use it on something they have no interest in. Without a minimum level of self-esteem, there will be a sense that the client is not worth the time invested by a trainer, making adherence unlikely, even if they do begin a program. The result of a diminished ability to think or concentrate is often automaton-like behavior. (i.e. You not only have to give them simple commands, you have to do it every time because recall is predicated on the ability to concentrate.)

The other criteria provide an indirect barrier to exercise through creating an insecure foundation. For instance, the fourth criterion is: Insomnia or hypersomnia. Without sufficient sleep, the body and mind are unable to recover from the day so that dealing with the next day’s challenges is even harder. With hypersomnia, the tendency is because sleep is not efficiently restful, so more hours must be spent in order to achieve the same effect. In both cases, the likeliest result is fatigue or loss of energy.

One way of looking at depression that might make it easier for non-depressed people to understand is through the strength and energy model (Baumeister, Muraven, & Tice, 2000; Hagger, Wood, Stiff, & Chatzisarantis, 2010). In this model, self-regulation is “assumed to be a global energy that is utilized on self-regulated tasks across different domains of action.” (Pomp, Fleig, Schwarzer, & Lippke, 2013) Self-regulation energy, as a unit, is considered to be a finite resource. When the energy is used up, the person reaches “ego-depletion”. Excessive usage of this energy in one area, may cause failure in other domains. In the case of those with Major Depression, a huge amount of this energy is being used to regulate the depressive symptoms, plus symptoms of stress and fatigue.  Thus there is little or no energy left for starting, much less adhering to an exercise program. This kind of economic paradigm can also be generalized to a “bandwidth” analogy. Much of a person’s bandwidth is taken up with maintaining basic system functions, leaving other functions little room for activation or expression.

It is true that exercise helps with the symptoms of depression, in some cases eliminating them altogether—as long as the exercise plan continues. Personal trainers working with clients who have depression must take into account the effects of depression when planning and motivating. Due to the effects of depression, the client is likely to have trouble starting even a single exercise session; and when they do, the client is very likely to have trouble adhering to the plan.

Given the low energy and low interest in being alive exhibited by people with depression, it may be best to start well below their physical threshold in order to provide them with 1) an easy success and 2) the beginnings of the normalizing effects of exercise on the brain. Progress will likely be slow since pushing the client’s limits early and often will overstress their ability to cope with unsuccessful attempts; remember, they are spending a greater than normal amount of self-regulation energy just to remain functional in any capacity. Sincere praise for what was done correctly will help with self-esteem, and if you can point out when they self-correct, it will improve their self-efficacy; both of which makes it more likely they will adhere to a plan.

References

American psychiatric association. (2009). Diagnostic and statistical manual of mental disorders text revision (DSM-IV-TR). Washington, DC: APA.

Baumeister, R.F., Muraven, M., & Tice, D.M. (2000). Ego depletion: A resource model of volition, self-regulation, and controlled processing. Psychological Bulletin, 18, 130-150.

Butcher, J.N., Hooley, J.M., Mineka, S. (2007). Mood disorders and suicide. In Abnormal psychology (13th ed.) (pp. 225-275). Boston:Pearson Education, Inc.Hagger, M.S., Wood, C., Stiff, C., & Chatzisarantis, N.L. (2010). Ego depletion and the strength model of self-control: A meta-analysis. Psychological Bulletin, 136, 495-525.

Lee H., Ohno M., Ohta S., Mikami T. Regular moderate or intense exercise prevents depression-like behavior without change of hippocampal tryptophan content in chronically tryptophan-deficient and stressed mice. PLoS ONE 8(7): e66996. Doi:10.1371/journal.pone.0066996.

Lorenzetti V., Allen N.B., Fornito A., Yucel M. (2009). Structural brain abnormalities in major depressive disorder: a selective review of recent MRI studies. Journal of Affective Disorders; 117:1—17.

Pomp, S., Fleig, L., Schwarzer, R., Lippke, S. (2013). Effects of a self-regulation intervention on exercise are moderated by depressive symptoms: A quasi-experimental study. International Journal of Clinical and Health Psychology, 13, 1-8.

Strawbridge W.J., Deleger S., Roberts R.E., Kaplan G.A. (2002). Physical activity reduces the risk of subsequent depression for older adults. American Journal of Epidemiology; 156:328—334.

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