One of the most confusing symptoms of depression can be what psychologists call “anhedonia“. It literally means the inability to experience pleasure. The way I often describe that to my patients is feeling as though your color television has suddenly gone to black and white. All of the joy, interest, enthusiasm and excitement just drains out of things. You find yourself wandering aimlessly through your previous life, unable to extract even small amounts of pleasure from things you used to love. This leads to a lot of other changes such as weight loss (food has no taste anymore), decreased sexual activity (you have no interest) and social isolation (you don’t enjoy being around people anymore and so the energy required to do so just doesn’t make sense).
The death of Robin Williams made me think a lot about depression. Like many people I grew up on him. Interviews I read of him sounded so alive, so joyous. He seemed as though he was the kind of person who could have fun with anything, even flossing his teeth. We now know that this was only one side of him. That deep down he struggled with “the black dog” (Winston Churchill’s description of depression) as have many famous people throughout time. I found myself wondering how, with all of the resources available to a person of his status, he had not been able to be successfully treated? Depression is common– one in 6 Americans will suffer it at least once in a lifetime. Many of us more than once. And yet suicide is thankfully rare– typically one in ten thousand Americans per year (1). How could he have succumbed?
I started thinking about my own practice. Depression is probably the single most frequent symptom that people present with. The causes of course will vary. Divorce, infidelity, job loss, death of a loved one, addiction and any other significant stress or loss you can imagine. But the symptom itself is the same– persistent sad mood, changes in appetite, changes in sleep, morbid thoughts, guilt, reduced sex drive, impaired mental function and of course anhedonia. While research continues to support the idea that psychotherapy is equally effective to medication for mild to moderate depression, most therapists do acknowledge that for severe, suicidal depressions medications can be life-saving. And yet only about 50% of people who take medications derive lasting benefits from them. The other 50% either never respond, respond only partially or respond at first and then eventually not at all. I have personally encountered a few situations in which this was precisely the case.
A recent research article in Nature magazine (July issue 2014) looked at the neurochemical mechanisms of anhedonia and may give rise to a new and more promising type of antidepressant medication. This is good news because all commonly used antidepressants today are based on modifying one or more of just a handful of neurotransmitters– serotonin, norepinephrine or dopamine. Once these neurotransmitters have been effectively increased, if the patient does not respond, there is nothing else to be tried. We have been stuck at this plateau in treating depression via medication for more than 50 years. So a new type of mechanism by which to treat depression via pharmacology can be life-saving news for those 50% of people who do not respond to traditional antidepressants.
The article discussed the motivational center of the brain and a hormone called melanocortin. Researchers put mice under chronic stress and then looked at the impact on the melanocortin receptors in the nucleus acumbens, a large part of the reward circuit in mammals. Deep brain stimulation of the nucleus accumbens has helped people with severe depression who have not responded to medications (2). But most people would much rather take a pill than have an electrode implanted in their brain. So figuring out how to achieve this effect via a medication could be a huge step in expanding our armamentarium to fight depression.
After being chronically stressed the rats showed an increase in melanocortin receptors in the nucleus accumbens. And this lead to a decrease in the signal strength of those receptors. The upshot was that the mice showed symptoms of anhedonia. When offered a choice between regular water or sugar water (which apparently mice love) the stressed mice showed no preference. The researchers upped the anti and gave the mice a choice between water and cocaine. Amazingly the chronically stressed mice showed no preference. So even a highly rewarding substance like cocaine, which normal mice will prefer to food and water to the point that they will literally starve to death or die of dehydration, was of no interest to these mice. This is a powerful example of how depression can absolutely suck the enjoyment out of anything and leave one feeling that they have nothing to live for.
While this research is ground-breaking and should lead to new classes of medications for the treatment of depression, it’s too little to late for the hundreds of thousands of people who succumbed to the siren’s song of suicide. That’s the sad reality of the state of science, that we know so little about so many aspects of our own brains and bodies. But I do hope that in the future we will have more treatments available to prevent amazingly talented, kind and descent people like Robin Williams from giving up hope. In the meantime I charge each and every one of us who either struggles with depression or knows someone who does to reach out and ask for help. Even when it feels like there is nothing left to hope for. If there is one thing I have learned in my 20 years in practice it’s that people can change, depression (and anxiety and a host of other symptoms) can remit and people can go on to be happy. I have seen it happen over and over. So please hold on to hope, and offer it to those who have lost it. Reach out. No one needs to face things alone and with help people can overcome.
Dedicated to Robin Williams, an amazing entertainer and lost much too soon.
With admiration and respect,
1. American Foundation for Suicide Prevention, www.afsp.org
2. Bewernick, B. H., Hurlemann, R., Matusch, A., et al. Nucleus accumbens deep brain stimulation decreases ratings of depression and anciety in treatment-resistant depression. Biological Psychiatry’, 2009 67: 110-116.