Depression, schizophrenia and seasonal affective disorder are all known to suppress the sense of smell and some University of Dresden Medical School researchers think they now know why this occurs. This loss of smell may be due to a part of the brain which is responsible for the sense of smell being smaller than normal, they say.
The researchers took 21 people who were depressed and 21 people who were not depressed and exposed them to a faint odor, gradually increasing its concentration, until the people were first able to smell it.
They also used magnetic resonance imaging to measure each volunteer's olfactory bulb, which is the part of the brain that allows us to sense smells.
They found that the non-depressed volunteers were able to detect the smell at a much lower level than the depressed volunteers. In addition, the depressed volunteers had much smaller olfactory bulbs than their non-depressed counterparts; and, the more depressed the person was, the smaller their olfactory bulb was.
Why does this effect occur? The researchers speculate that perhaps it may be linked to a process called neurogenesis (the formation of new nervous tissue). Depression is known to inhibit neurogenesis, and it may prevent the olfactory bulb from growing as large as it should be. If this explanation is found to be correct, they say, it could allow physicians to monitor the effectiveness of depression treatment by measuring the size of the olfactory bulb.
The study appears in the journal Neuroscience.
I caught a respiratory virus (probably a Coxsackie B virus) that caused both loss of my sense of smell, as well as causing depression symptoms.
It is known that certain types of depression originate in the hypothalamus, which can be dysregulated by viruses like coxsackievirus B.
The hypothalamus is also situated close to the olfactory bulb, and thus one wonders if the same infection may also be damaging or dysregulating the olfactory bulb (or is afferent nerves), thereby leading to loss of smell.
In general, there is growing evidence to suggest that a huge amount of human physical and mental health conditions are underpinned by microbial infections.
ive been in and out of depression 4 over 3 years ive attemted suicide 3 times, dont know wat causes it exactly but i hate being like this. Dont know wat il do next
I have suffered from depression my whole
life and have been taking medication for 25 years. Most
of the time the depression has been better than it has
it has been worse. The last severe “down” I had was accompanied by my active alcoholism. When I was in
treatment we would go for walks outside and I was amazed
by the smells. Ever since I got sober (2 years ago) my depression lifted and I have continued to have a keen sense of smell.
Thank you for writing about it. Now I know it is not just my imagination.
Interesting. As my depression wanes, I do notice I am more aware of smells good and bad. Thanks for the article and the comments.
Now as a Sr. citizen I realize that I’ve suffered from bouts of depression since I was a kid. I’ve been smoking cigarettes since age 14, unsuccessfully trying to quit more times than I can remember. I always thought that my loss or lack of sense of smell AND taste was due to smoking, not depression! More interesting, many times I detect smells that really aren’t there (I ask people around me if they smell this or that, always with a negative response.) Could detecting “ghost smells” also be a depression effect?
I lost my sense of smell as a teenager. I started to show signs of depression around the same time. I smell strong bad odors if I really don’t like a person anymore. Occasionally, I can smell.
The doctors couldn’t determine why it had occurred. It makes sense.
sophia: I suffered like that for 50 years before I gotthe right kind of help. It seemed everytime I just couln’t stand to live with it any longer, it would ease up, I would feel good again, and put off suicide for “a little longer”. Then it was back again. A roller coaster that wouldn’t stop and let me off.
One day a new workmate noticed and told me “oh, you’re bipolar, so am I”. I went to my Dr and asked for an evaluation. He sent me to a PSYCHIATRIST (my psychologist never “got it”) and he said I was biolar II, a slightly milder form. gave me Neurontin (after Paxil and Wellbutrin for depression was making me manic) The Neuontin,or gabepentn (generic) stopped the rollercoaster almost immediately. I have a life now. No more suicide attempts.
Honey, get an evaluation. A psychologist just helps you learn how to think, so you don’t cause your own feelings by wrong thinking.
Instead, depression illnesses are medical conditions, like diabetes and ae problems with the regulation of nerve impulses-too much or too little. You need a psychiatrist -they are medical doctors, they specialize in the human brain. Write down all your ups and downs, all your feelings, your behavior problms, people’s reaction to you, your famiy history of any depression.and look for a cycle. Take this lit o the doctor. I have very short cycles . Others go months or years between cycles. But they aways return and mess up yourlife, your family, your job, your marriage. You can get help. If you can’t afford it, the doctor can send you to places that wll pay for it. Get evaluated. Now. AND DON’T EVER GIVE UP.
This is really fascinating. I am 51 and have had bouts with depression and panic disorder since I was in my mid-twenties; and been on meds since I was 30. When I was 50 years old, I lost my job (and have been looking ever since with no luck), I’ve been taking some very stressful post-graduate online classes and things within my family are a mess. Three different psychiatrists have had trouble getting my meds right this time (although this third one is probably going to be close enough to get by).
However, about two years ago (probably when the spiral into depression started), I lost my sense of smell after a long bout with the flu, and have not gotten it back.
This is really interesting because perhaps I will be able to tell when my meds are 100% correct when I can once again begin to smell faint odors. It gives me something to look forward to.
This is so interesting. My sense of smell is really off. In order for me to smell something, it has to be very strong. I have been suffering with depression for 10 years.
exactly now I realize that I am also suffering from week smelling sense. I thought it might be because of my polyps. Thanks for the information.
I’ve been depressed, and under treatment, my whole adult life and have never noticed a problem. But now I’m concerned that maybe the cat box smells worse that I think it does!