Wednesday 2 January 2013

Treatment v management in psychiatry - tranquillizers and antipsychotics (from Conrad M Swartz and Edward Shorter)

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Superb insights excerpted from pp 170-172 of Psychotic depression by Conrad M Swartz and Edward Shorter. Cambridge University Press, 2007. Words in square brackets were added by me, editorial cuts are indicated by ....

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For the sake of discussion, we could say that one way to terminate all hallucinations, delusions, insomnia, and complaints of low mood and loss of interest [from someone with Psychotic Depression] would be to anaesthetize the patient to unconscousness...

Yet this would be symptom management, not treatment, scarcely a desirable or sensitive form of practice. 

More feasible than complete anaesthesia are drugs that only partly inhibit the brain from operating and superficially appear to leave the patient conscious. This is tranquilization.

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Physiologically, benzodiazepine and barbiturate tranquilizers [and one could add alcohol] are called 'depressants' because they diminish brain functions.

In low to moderate doses they inhibit learning, recall, coordination, awareness of complexity, problem solving, willpower and attention.

In larger doses they are general anaesthetics and can cause unconsciousness...

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Antispychotic [or neuroleptic] tranquilizers inhibit the functioning of only some areas of the brain: those related to new thoughts, novel problem solving, social complexity, initiative and motivation. 

These functions are housed in the prefrontal section of the brain. This sounds like a small fraction of the brain, but in humans the prefrontal region is almost half the brain cortex.

Its functions represent the essential differences in psychological performance between humans and animals, and also between human adults and children... 

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The deficits in psychological performance caused by antipsychotic drugs mentioned here occur similarly in patients with Parkinson's disease...

Both with antipsychotic drugs and Parkinson's disease, the function of dopaminergic brain cells is deficient...

Both groups... show impairments in problem-solving abilities, planning, initiative taking, and dealing with complexity...

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The behavioural results... vary with the particular antipsychotic drug.

Dopamine-blocking antipsychotic drugs - such as haloperidol, perphenazine, and risperidone- decrease motivation to speak, together with lessening complexity and amount of thought. 

Some of the more recently introduced antipsychotics (e.g. olanzapine, clozapine, and quetiapine) decrease thought complexity more than motivation to speak; and because the patient speaks abundantly the thought simplicity is easier to notice. 

Decreases in self-discipline and organization contribute to the weight gain patients experience from olanzapine, clozapine, and quetiapine. 

Olanzapine and clozapine also obstruct the function of the medial prefrontal cortex, which causes apathy, somnolence, and generalized weakness. 

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Anaesthetizing brain function is surely a last resort. 

It is management, not treatment. 

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8 comments:

dearieme said...

What treatments are there that work?

Samson said...

So where do you take this, then, Bruce? Antipsychotics aren't a "cure", sure. What's a better idea?

Bruce Charlton said...

@d &S - The short answer is: ECT/ electroshock.

As the authors point out, ECT is unusual in being both the first treatment to be discovered for melancholia and psychotic depression, and also by far the best.

dearieme said...

Ahoy, Bruce. Given your remarks about Who Become Scientists Nowadays, I thought this might interest you.
http://www.jbc.org/content/278/7/4369.long

Donald said...

What do you make of Freud in relation to modern psychiatry?

Bruce Charlton said...

@Donald: In essence, Freud was a fraud. Best ignored (unless you are an historian).

Donald said...

Any good intro texts for a medical student? How do you approach the issue of delusions/psychosis and miracles/revelations as a Christian bot personally and to colleagues (would you even bother trying to convince a secular colleague on distinguishing the two?)?

Bruce Charlton said...

@Donald

David Healy's Psychiatric Drugs Explained is excellent - it is the set book for my course at university.

I have written about delusions

http://www.hedweb.com/bgcharlton/delusions.html

With respect to miracles and revelations - they do not have a formally different status than other beliefs about the world - belief in miracles and revelation is natural and spontaneous. It is the ruling out of m and r as possibilities which is weird and unnatural - and probably pathological in the sense that groups which deny ms and rs have sub-replacement chosen-fertility.

In a biological sense, the difference between a pathological delusion and a true belief would relate to adaptiveness. This is not a matter of being happy, but a matter of reproduction - and it can be assessed only on average and in specific contexts: thus a pathological delusion would reduce fitness (which is reproductive success).

Of course it might be difficult or impossible to trace the causal pathway from belief to reproductive success - especially given that there is so much 'noise' from chance and between-individual differences.

But it is easy to show that religiousness (traditional orthodox religiousness) is necessary (but not sufficient) to human reproductive success - and from that that belief in miracles and revelations is not pathological (and that modern spirituality and atheism and materialism ARE pathological).