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Medical Dopamine agonists and dopamine antagonists

  1. Jan 11, 2007 #1
    My psychiatrist has diagnosed me with both depression (low dopamine) and schizophrenia (high dopamine) and has me on dopamine antagonist medications (atypical neuroleptics).

    Once in a while, I ask for an anti-depressant to see if it will improve my mood. I have read that these are dopamine agonists -- reuptake inhibitors. They increase dopamine levels.

    Are the two medications counteracting each other? My psychiatrist told me it has to do with regions of the brain that are affected; dopamine levels are relevant in one node of the brain for depression and another for schizophrenia.

    If so, should I just take the dopamine antagonists, or the dopamine agonists?
     
  2. jcsd
  3. Jan 11, 2007 #2
    A few things... This is a simplistic view of things - you must understand that I'm no where near a fully qualified phychiatrist!...

    'Typical neuroleptics' work by blocking D2 dopamine receptors...

    You are taking 'atypical neuroleptics' and the very reason thaty are atypical is because they do not strongly block D2 dopamine receptors (like typical neuroleptics)... There main mechanism of action is thought to be due to the blocking of serotonin (5-HT) receptors...

    The major mechanisms of action of anti-depressants are to increase the levels of two other neurotransmitters - noradrenaline and serotonin...

    As for the antidepressant reuptake inhibitors... There are two classes of uptake inhibitors...

    1) Serotonin selective reuptake inhibitors (SSRIs) - and this includes fluoxetine (aka. prosac)... As the name suggests they block serotonin reuptake and so increase levels of serotonin in the brain...

    2) Tricyclic antidepressants - e.g. amytyptiline... These reduce uptake of both noradrenaline and serotonin, which increases the level of both in the brain...

    NB. Are you sure that these actually increase the levels of dopamine? I didn't think anti-depressants did... If they do, it is a side effect - it isn't their mechanism of action...

    I can't really say much else... I would really need to know the precise drugs you are talking about... There are many different drugs of the same class that act on many different types of receptor and many different sub-classes of each type of receptor and sometimes even subtypes of the subtypes... lol
     
    Last edited: Jan 11, 2007
  4. Jan 11, 2007 #3
    thanks for the response

    You're right, I forgot to write about serotonin. However, that chemical is less familiar to me than dopamine; the literature I read went on and on about the dopamine hypothesis concerning schizophrenia.

    According to what I read: dopamine is a stimulation-pleasure chemical in the brain. People on certian types of street drugs have higher dopamine levels and experience psychotic symptoms such as hallucinations and delusions.

    Similarly people who have sex or play sports have high levels of dopamine -- along with adrenaline and noradrenaline (epinephrine and norepinephrine).

    Here's a good short article: http://www.anxiety-and-depression-solutions.com/insight_answers/dopamine.php

    Try this on: I have schizophrenic symptoms (lack of rational thought) and paranoia (fear of others), according to one of my therapists. What would my frontal lobe dopamine level be, then?

    Now, concerning serotonin: it regulates mood, emotion, sleep, and appetite.

    Therefore, the 1-2 combo punch is to antagonize both dopamine and serotonin levels for schizophrenia. This seems to do the trick better than the typical neuroleptics of the 1950s, that only brought dopamine levels down.

    In depression, I thought I read that dopamine levels were too low, but the article above disputes that, so I'll accept it and move on. Serotonin is the chemical associated with depression.

    http://www.biopsychiatry.com/serotonin.htm

    Serotonin reuptake is blocked by SSRIs to improve mood; thus serotonin levels are raised.

    However, the additional complication is bipolar mania. This is the feeling of elation. Bringing down a manic person is performed by giving dopamine and serotonin antagonist. And then an anti-depressant is prescribed to cure the low pole, depression. (This conflict in medications is similar to trying to treat depression and schizophrenia.)

    One problem with serotonin-raising anti-depressants is that they can cause mania. See? It's pretty complicated to be adjusting all these chemicals.

    Now, the anti-depressants I've taken were Celexa and something else -- another SSRI -- to answer your question. Like you said, Celexa is an SSRI so you're right, it doesn't affect dopamine.
     
    Last edited: Jan 12, 2007
  5. Jan 12, 2007 #4
    You are reading into things too much... There are many faults with the "monoamine theory of depression"... For example, cocaine, which also increases monoamine levels in the brain is not an anti-depressant and if it was as simple as levels of dopamine in the brain then why does it take 2-3 weeks for antidepressants to have effect... Basically, it isn't as simple as levels of neurotransmitter levels...

    And as for schizophrenia it is a similar story...

    I'm dying to know how exactly do you get a diagnosis of a "paranoid schizophrenic" - it isn't something you'd normally go to the doctor for... and as for your question, i think i answered your question before... neurotransmitter levels do not explain phychiatric illnesses...
     
    Last edited: Jan 12, 2007
  6. Jan 12, 2007 #5
    Alright, then...

    My intent is to try to gain a minimal insight into pharmocology. Thus I have been reading about the medications and the neurotransmitters on the Internet, gleaning what I can from them.

    Even if it is an oversimplification, the main thrust of the writing on anti-psychotic and anti-depressant medications is the effect the medications have on dopamine, serontonin, and noradrenaline.

    Therefore, that is what I try to work with. If you feel this is in error, I will accept your correction, although I'm glad you corrected me on the serotonin vs. dopamine part -- I hope to bring that up with my psychiatrist, if he lets me do so. Usually he is pressed for time, as he is always 20-40 minutes late taking me in.

    As far as how I got the diagnosis, it's a long story, so I will give you a brief version: In 1997, I suspected that a married woman's husband was going to come after me. I had gone out to lunch with the married woman, that is all. I stayed at home with a firearm in case he tried to attack or kill me, so my mother took me to a regular doctor and he reassured me that I had nothing to worry about: married men do not avenge adultery. Such an act would be inconceivable and never happens in this universe. I didn't believe him and insisted that I was in danger. He had me go to a mental hospital and at that time, they had me take Risperdal to give me "courage".

    At the time of my hospitalization, I was diagnosed as depressed with psychotic features. Since then, my diagnosis has changed many times: schizophrenia, paranoid schizophrenia, sociopathic personality disorder, schizoaffective disorder (schizophrenia + depression). This is due to the scantron tests and verbal assessments.

    That is a very condensed summary, friend. If you want a longer version to answer your question, I'll provide it as well.
     
  7. Jan 12, 2007 #6
    Yes, this is true... but my point was that just because anti-depressants work by increasing the levels of neurotransmitter in the brain - you cannot say from that depression is caused by low transmitter levels... There has been no proof of this and various problems for this theory...
     
  8. Jan 12, 2007 #7
    Very well, then...

    If you say so, I don't want to continue the topic then.

    Revenged, thanks for your insights. I hope to discuss and share them with concerned others.

    o| Hiram
     
  9. Jan 14, 2007 #8

    Moonbear

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    I'll elaborate on the problem with the hypotheses. The real problem is that we don't have a way of directly measuring what is going on in the brain of someone with schizophrenia all the way down to the neurotransmitter level...other than post-mortem. So, the hypotheses on the causes for the disorder are based on what's known about the pharmacology of the drugs that treat them. However, we don't know if the drugs are directly affecting the area that is "abnormal" or is indirectly relaying a signal via other neurons to that area.

    Another neurochemical that is under study for schizophrenia is neurokinin B. One drug targetting that system is in phase II clinical trials, so it's too soon to know what the outcome will be. Another drug was cancelled after the Phase II trials due to side effects, but I don't know what the side effects were that were the cause of the cessation of work on that drug (I just came across an announcement from the drug company in their annual report to stockholders).

    Some of the difficulty, as you have experienced yourself, is that it can be very difficult to distinguish between several disorders with similar symptoms. Though, that's made harder if your psychiatrist isn't spending adequate time with you (ask him if you pay half the price for the office visit if he only spends half the time with you!).

    You may want to see a different psychiatrist if the one you're currently seeing is not taking enough time for you to ask the questions you need to ask.

    All of the drugs currently prescribed for schizophrenia have side effects of varying degrees, and it's one of the reasons it's really hard to keep schizophrenic patients on their medication.

    Unfortunately, nobody here can advise you better than your psychiatrist whether you can take an antidepressant with your other medications. With such a complex problem, seeing a second psychiatrist for another opinion might not be a bad idea anyway; they may be aware of different approaches than the one you're seeing.
     
  10. Jan 15, 2007 #9
    Moonbear, thank you for the information about neurokinin B; I hadn't heard that.

    In regards to trouble with diagnosis confusion due to disorders conferring from similar symptoms, that is exactly the problem with me: social withdrawl (including spending too much time on the computer and not with people, although I said a forum like this does have people on the other end) is both typical of schizophrenia and depression; therefore, if the medications do affect serotonin in opposite directions, which one would be better to take? Ack!

    Now, in regards to my psychiatrist, he is seeing me through Medical/Medicare, as I do not pay or have private insurance. So I can't really take issue with him on payment as per time of visits. It was hard to find a treatment program that would take Medi/Medi that was not far from where I live; I've nearly exhausted my treatment options in North County of San Diego.

    At least I can come to this forum and post my questions and get good responses. It shall have to suffice.

    o| Hiram
     
  11. Jan 15, 2007 #10

    Moonbear

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    You can't really look at just individual symptoms to come up with a diagnosis. Your psychiatrist needs to evaluate all of your symptoms together, along with when they developed (if you or others around you can recall that). It's hard to simply say X number of hours online is too much, or a sign of social withdrawal. It would have to be taken in context of how you interact with others during the time you're not online, or how you interact with those online as well (as an example, I've met up in person with several people I've met online and expanded my network of friends in that way...that's a fairly social use of the medium).

    Well, you could tell him that us taxpayers take issue with him not giving us our money's worth if we're getting the bill for the time he's not spending with you. :biggrin: That's really a shame that you don't have other options for treatment, or even for a second opinion. I could rant on and on about not making treatment available for those whose illnesses are most likely to interfere with their ability to hold a job and obtain medical insurance, and once you get adequate treatment so you can function normally, it's classified as a pre-existing condition so you still can't get insurance. :grumpy:

    Just remember that we are not medical professionals, and even if someone here is, they can't diagnose you over the internet, so we can talk about the science, but when it comes to treatment decisions, you need to work with your personal physicians.
     
  12. Jan 15, 2007 #11
    I'm intrigued...

    How can you tell what is going on at neurotransmitter levels at post-mortem?
     
  13. Jan 15, 2007 #12
    Moonbear: Yes, there's more to the story that I have not written, and I don't know if it's necessary to write a long account of the history of my symptoms here.

    I agree with your more strict interpretation for a diagnosis, but in group therapy, as far as my experience goes, symptoms are talked about in a more casual and informal way, and may get misrepresented along the lines of the criteria you listed (for starters, of course). Not everyone in the general populace holds to such stringent standards, and this is true about patients if not the psychiatrists.

    (Before you tell me that patients don't make the diagnosis, I will agree and say that they still have to report the symptoms.)

    Your argument about expanding your social circle would not apply to me because I've hardly ever met people in person from the Internet. I agree that it would be a viable argument. Anyway, I'll move on.

    To shorten this post, the Catch-22 you referred to entails money issues that I don't know if we should go into, and I understands the risks involved in asking physics experts (presumably, this is a website for physicists) questions about medicine and psychiatry, but I'm willing to take those risks for the reason we already went into: you have been willing to hear me out.
     
  14. Jan 15, 2007 #13

    Moonbear

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    You can use immunocytochemistry or in situ hybridization to look at the cells producing the proteins or mRNA, respectively. This is not easy with human post-mortem tissue because of the delay from the time of death until all the permissions are obtained from next of kin for collection of the tissue, especially for the normal controls (there are a lot more people who have mental illnesses who are willing to donate brain tissue for research after their death in the hope their illness will help in finding a cure for others than there are "normal" controls available, so that also hinders the work). You can also use Western Blot or quantitative PCR to assess regional changes in protein or mRNA expression. The former two methods allow you to look at the locations of cells and their connections more readily, while the latter two methods are better at quantifying levels of expression within larger regions, but won't give you cellular resolution. I can go into more detail on neuroscience methods, including the various strengths and limitations of different approaches, in a different thread if you want to learn more, since I think it would stray too far from the main point in this thread.

    You don't need to share any more than you want to share. We can discuss the topic in general rather than specifically with regard to your own symptoms and diagnosis so it doesn't get too personal for you, but still answers the questions you have.

    All good reasons to keep the discussion generally about schizophrenia and treatments rather than specifically about your symptoms. This way, we don't need to play armchair psychiatrist to see if your symptoms fit our understandings of the illness.

    Much of the site is for physicists, but there are some of us here who are biologists. We had a growing population of neuroscientists here (researchers, not clinicians) for a while, which is what sprouted the interest in a separate mind and brain forum, but some have wandered back off again. I'm partly a neuroscientist. I'm not classically trained in neuroscience, but my research involves it, so I've worked with neuroscientists to acquire that knowledge and am a member of the neuroscience center at the university where I work.
     
  15. Jan 15, 2007 #14
    I was ready to list my symptoms, but you said you would prefer me not to, so now I won't. As you wrote, let us discuss schizophrenia (and depression BTW) in general. And I just knew I was going to get something in your response about everyone here being physicists...You're response was very informative so I'm glad no harm came out of this slip.
     
  16. Jan 25, 2007 #15
    Why not eat healthy food, excercise daily and keep occupied doing puzzles and brainteasers instead of taking medication?

    I think hearing your symptoms is key.
     
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