Dopamine dependent SAD

MS marshmallow5 at yahoo.com
Wed Oct 4 16:28:34 EST 2000

> Have other dopamine dependent conditions been described?

Parkinson's disease namely, which does show a disproportionately high rate
of depression. Dopamine has been implicated as playing a role in several
other disorders including schizophrenia, ADHD, Lesch-Nyhan disease, and
drug/alcohol addictions to name a few.

> I there any validity in the above theory?

Youre hypothesis seems consistent. I wouldn't say it's the only possible
explanation, but it seems to make sense. Whatever the problem is, the drug
treatment seems to help. By analogy, schizophrenia may not be a disorder of
dopamine levels or receptors, but drugs that block dopamine do alleviate the
problem. Another example: Parkinson's disease results from a lack of
dopamine in the basal ganglia, which is treated by increasing dopamine
activity OR by blocking acetylcholine receptors. A treatment that works only
means it restores somewhat of a functional balance. Whether or not its the
actual cause (or one of the causes) is another step.

> Does melatonin inhibit dopamine production? (producing seasonality)

To echo my last statement somewhat, SAD may cause an imbalance of activity
in limbic and frontal areas of sufferers and dopamine may just be restoring
the proper balance.  But what youre suggesting is another logical
possiblility: melatonin may directly or indirectly modify DA function. Do a
search on medline. Unfortunately, there is also dopamine in the retina, so
there's probably going to be tons of research on melatonin's effects on
retinal dopamine which you'd have to sift through.

> Could bipolar 1 disorder be serotonin dependent and bipolar 2 disorder be
> dopamine dependent?

I think other things are at work in bipolar disorder as well. I know more
recent research has focused on intracellular messengers and G proteins.

> Is human happiness as simple as a sole chemical and it's activity?

I 'd have to say that the emotion of happiness, as all emotions and
subjective experience are an aspect of brain function. That means a pattern
of activity in related brain areas.  I regard mind, brain, and behavior as
three aspects of the same phenomenon.  The chemical messengers
(neurotransmitters etc.) modify the activity of brain areas responsible for
mood (namely frontal-subcortical and limbic structures).

I hope this helps.

marshmallow5 at yahoo.com

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jonconx <jonconx at MEblueyonder.co.uk> wrote in message
news:JM7A5.7498$gw4.955907 at news1.cableinet.net...
> I suffer from dopamine dependent Seasonal Affective Disorder.  In fall I
> start to become depressed (this is characterized by hypersomnia and
> paranoia).  This peaks in mid-winter and then fades out to become
> in May.  This is now controlled with bromocriptine which is a dopaminergic
> drug.  This is titrated against mood and used in the Fall and Winter
> Starting out with just 1mg at the beginning of September and peaking with
> 30mg in the last couple of months of January.  This is then faded out to a
> zero dose at the start of April .  Hypomania does not subsequently occur
> with this treatment.
> Small fluctuations in mood can occur with alcohol use, presumably as there
> is dopamine release and a high when intoxicated and then a lack of
> activity a few days later leading to depression and paranoia.  This
> within a couple of days.  Needless to say, I don't drink anymore and small
> fluctuations in mood rarely occur.
> I believe that with a lack of dopamine activity (i.e. in the winter) the
> post-synaptic receptors become super-sensitive (dopamine hungry).  This
> means they have a 'hair-trigger' and can fire inappropriatly.  In other
> words there is noise in the system.  This leads to paranoid thinking and
> overall lack of activity leads to inactivity, hyposomnia and depression.
> addition it could mean that adjacent receptors could fire inapproprately
> lead to thoughts which are not related clouding the issue and adding to
> paranoid/psychotic thinking.  After a period of dopamine deprevation the
> super-sensitive receptors can then 'over fire' when subjected to higher
> levels of dopamine (e.g. in the spring).  This leads to hypomanic
> with increased motor activity and mood which eventually settles down to a
> normothymic condition (till the fall).
> This can be backed up with by the action of dopaminergic drugs at
> stages of the disease process.  When there is normal mood (say july)with
> medication, the addition of dopaminergic drugs causes a slight lift in
> However, if thouroughly depressed and untreated(say January), the addition
> of a dopaminergic drug produce profound mania in the short term due to
> supersensitive post-synaptic receptors over -firing.  The receptors then
> downregulate and normal mood is restored.
> I wonder if anyone could answer the following questions:
> Have other dopamine dependent conditions been described?
> I there any validity in the above theory?
> Does melatonin inhibit dopamine production? (producing seasonality)
> Could this relate to seasonal control of dopamine synthesis and/or severe
> receptor instability?
> Are other psychotic disorders related to dysregulation of dopamine
> receptors?
> Is dopamine function related to immune function (if untreated, in
> I develop oral and nasal warts (yuk!) and developed such severe moluscum
> contagiosum lesions one winter I was believed to have AIDS (I'm HIV
> negative)
> If antipsychotic drugs control schizophrenia, why do they block
> receptors and cause an overall increase in dopamine concentrations, could
> they be working on above mechanisms?
> Could bipolar 1 disorder be serotonin dependent and bipolar 2 disorder be
> dopamine dependent?
> Is human happiness as simple as a sole chemical and it's activity?
> I am no neurobiologist, but if anyone could give me some guidence on the
> above, I would be most grateful
> Yours John Connelly
> Birmingham, England
> Email: jonconx at yahoo.com

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