Thursday, 15 October 2015

ClinicSpeak: limbic system and depression

Are you depressed? There is a biological reason for MSers to be depressed. #ClinicSpeak #MSResearch #MSBlog

"The lifetime prevalence of major depression in MS is ~50%; 1 in 2 MSers get depressed. This is way  and above what one expect in relation to the level of physical disability that MS causes. We know this because when we compare MSers to say people with rheumatoid arthritis with the same level of physical disability the incidence and life-time prevalence of depression is about twice as high in MSers. Why? It is almost certainly due to the fact that MS is a brain disease and affects neuronal circuits linked to mood. The study below using functional MRI shows that depression in MSers is associated with altered regional brain activity and connectivity patterns within the primitive brain system called the limbic system. What this is telling us that there is a biological/anatomical substrate to explain why MSers get depressed. I suspect this is related to damage that occurs as a result of MS inflammatory activity in the brain. In other words if we treat MS early and prevent this damage we should reduce the burden of depression in this disease."

"How do you know you are depressed? If you need help identifying whether or not you are depressed you can download this short questionnaire and complete it. If you find you are depressed can you please bring it to the attention of your family doctor, neurologist or MS nurse specialist. We have a lot of treatments for depression including lifestyle changes (exercise), counselling and behavioural therapies (CBT, mindfulness, etc.) and pharmacological interventions (antidepressants) that help MSers manage their depression."

Riccelli et al. Individual differences in depression are associated with abnormal function of the limbic system inmultiple sclerosis patients. Mult Scler. 2015 Oct 9. pii: 1352458515606987.

BACKGROUND: Depression is common in patients with multiple sclerosis (MS), although the brain mechanisms of this psychiatric condition in MS are poorly understood. Specifically, it remains to be determined whether depression in MS is related to altered activity and functional connectivity patterns within limbic circuits.

METHODS: Seventy-seven MS patients with variable levels of depression (as assessed via the Beck Depression Inventory) underwent functional magnetic resonance imaging while performing an emotional processing task. To conduct the functional connectivity analyses, the bilateral amygdala and hippocampus, two areas critically involved in the pathophysiology of depression, were chosen as 'seed' regions. Multiple regression models were used to assess how depression in MS patients was correlated with the activity and functional connectivity patterns within the limbic system.

RESULTS: Depression scores in MS patients were negatively correlated: (1) with the activity in the subgenual cingulate cortex; (2) with the functional connectivity between the hippocampus and orbitofrontal cortex as well as the dorsolateral prefrontal cortex, and (3) with the functional connectivity between the amygdala and dorsolateral prefrontal cortex.

CONCLUSIONS: Our study showed that individual differences in depression in MS patients were significantly associated with altered regional activity and functional connectivity patterns within the limbic system.

6 comments:

  1. I don't doubt any of this but surely an important factor is that as yet so many MSers are without treatment options.......

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    Replies
    1. Re: "so many MSers are without treatment options......."

      Yes, I fully agree, which is why we launched the policy document "Brain Health: time matters in MS". I hope you have all pledged your support for the policies? If not please do so via www.msbrainhealth.org. Thanks.

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  2. I think people are depressed because of the unpredictable+progressive nature of MS.
    If disability was fixed, I think people will find ways to cope. It is the downhill battle we are afraid of.

    If you find walking difficult, your fear will be the cane., if you use a cane you will fear 2 canes.
    If you use 2 canes you will fear the wheelchair. If you use a wheelchair you will fear the loss of upper limb function. If you have 0 mobility you will fear severe loss of cognition or vision.

    Many things like sexual dysfunction, loss of bladder control, extreme fatigue, pain, tremor might also
    be alongside you during your life.
    It just never lets go of you. Its always lingering behind you waiting to cause more and more damage.
    I don't mean to sound like the most pessimistic guy in the world. I am just trying to give my opinion on why MSers might be depressed.

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  3. Could episodes of (severe) depression in theory act as a marker of inflammation? A form of a relapse that manifests on a patient's mental instead of physical health? After all, not everyone's MS is the same and should MSers who have these episodes be supported better/differently to others?

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    Replies
    1. RE: "Could episodes of (severe) depression in theory act as a marker of inflammation?"

      Yes, low mood is linked to sickness behaviour that is part of the behavioural response to inflammation. However, this is not usually described as overt depression. The later is a matter of degree.

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  4. I've suffered depression a few times, but as I was working I paid for private Psychotherapy so that I didn't have to take time off work. It was a different mental health problem to what I have now. The struggle now, is having to completely change my life and it is not going to get better. Previously, it was more complex, accompanied by migraines and I recognise this as not being straightforward. Some people get depressed when they have cancer and some don't. I believe there is a subtle difference.

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