Explaining the Antidepressant Effect

December 19, 2011

Into the Light

In addition to blog postings related to the business of psychotherapy and psychiatric practices I occasionally address clinical matters here. I have found the information in this piece to be very useful in offering a plausible explanation of how antidepressants work and the expected time course of that effect. Providing this information is good for the patient’s treatment and for your business.

I tell my patients about at least two mechanisms of action – an early calming, likely due to amygdalar modulation (a simmering down of the brain’s threat assessment circuitry) and a later one entailing improving mood, sleep, and functioning in general due to the gradually increasing concentration of BDNF – brain derived neurotrophic factor – which promotes neurogenesis and a “healthier” functioning brain, especially the massive network of dendritic trees.

From “Stress, Depression, and Neuroplasticity: A Convergence of Mechanisms” published in Neuropsychopharmcology Review we read:

“Increasing evidence demonstrates that neuroplasticity, a fundamental mechanism of neuronal adaptation, is disrupted in mood disorders and in animal models of stress. There is evidence that chronic stress, which can precipitate or exacerbate depression, disrupts neuroplasticity, while antidepressant treatment produces opposing effects and can enhance neuroplasticity. We discuss neuroplasticity at different levels: structural plasticity (such as plastic changes in spine and dendrite morphology as well as adult neurogenesis), functional synaptic plasticity, and the molecular and cellular mechanisms accompanying such changes. Together, these studies elucidate mechanisms that may contribute to the pathophysiology of depression. Greater appreciation of the convergence of mechanisms between stress, depression, and neuroplasticity is likely to lead to the identification of novel targets for more efficacious treatments.”

Antidepressants help our patients in many ways. I will discuss other proposed mechanisms of action in later postings. A more sophisticated understanding of their mechanisms of action will help us combat what I heard an imminent psychoanalyst say at a dinner gathering of other analysts – “My God, patients there (a local psychiatric residency program) are more likely to get Prozac than psychotherapy!” This was an old greybeard spouting dogma. This position now should be considered malpractice. Certainly Freudian psychotherapy was a tremendous advance over applying electrical shocks to hysterical patients but  that was such a long time ago.

More accurately, antidepressants – given that there are indications for their use and the patient can tolerate the possible adverse effects – can quickly begin the process of  helping our patients move out of the dark pit of depression. They work quickly but the full bloom of their effect takes several weeks. And understanding the various ways they effect our patients’ brain and social functioning will help us more convincingly inform and engage them.

So – What do you tell your patients about how these medications can help them?

  1. Kirk Brewster December 20, 2011 Reply

    Insightful blog..I am reminded of the monthly mtgs at NYPsychoanalytic re: Neuropsychoanalysis. Fascinating stuff and a needed missing link between brain science and our 'art'. I plan to use the explanation with patients who might be able to grasp it but what to do with the suffering patient who is paralyzed by the stigma of 'meds.' How does one clear that hurdle so as to be able to take the next step as mentioned in the blog.

    • William Lynch December 21, 2011 Reply

      Hi Kirk,

      I'm not sure what you are referring to as "the next step mentioned in the blog". I, too, meet resistance to using medications
      even in people who are gravely ill. One fellow recently was clearly paranoid, guarded, and argumentative. I told him
      that my treatment recommendations, including using medication, we're my best guess at what he needed. Treatment with
      me was his choice but I could not continue treatment unless he agreed with it. He became so hostile that I asked
      him to leave.

      Now that is an extreme case. For the more usual reluctance I generally say that it is my goal to help you feel better
      and function more optimally as soon as possible and that a medication trial is indicated (if it is) and that if they choose
      to not use the meds, that's ok with me, they'll be in treatment longer and the results may well be sub par.

      People, including many therapists, are way behind the curve in terms of the efficacy of the meds now in our "tool box".

      Thanks so much, Kirk, for your comment and question.


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