In the olden days of psychopharmacology — the 1950s through the 1980s — most prescriptions for antidepressants were written by psychiatrists. Now, Valley Mental Health psychiatrist Dr. Michael Measom says, "the vast majority of depression is treated by family-care doctors."

Many of those family physicians prescribe SSRIs (selective serotonin re-uptake inhibitors), drugs with familiar names like Prozac, Paxil and Zoloft. They are comfortable prescribing SSRIs because unlike the older classes of antidepressants — tricyclics like Elavil and MAO (monoamine oxidase) inhibitors like Nardil — the newer ones have fewer side effects and are hard to overdose on unless taken with other lethal drugs.

Dr. Measom defends the use of antidepressants — "it's a disorder of one of the organs of the body, the organ you use to relate to the world" — and notes a combination of antidepressants and psychotherapy have proven the best treatment. A study published earlier this week in the Journal of the American Medical Association, for example, concluded that a combination of Prozac and talk therapy works best for children and teens suffering from depression.

To warrant treatment with antidepressants, Measom says, a patient should meet the criteria for major depressive disorder, with symptoms — for at least two weeks — that include changes in sleep and appetite, decreased sex drive, problems with concentration and suicidal thoughts. Physical symptoms for which there is no clear cause may also be a sign of depression, Measom says.

But not all depression looks alike, not all antidepressants work the same, and not all bodies react the same way to the drugs. "If you pick any single SSRI and tried it on a random group of 100 patients with clear-cut depression," University of Utah School of Medicine psychiatry professor Dr. David Tomb says, "you would find significant improvement in about 60 percent, and a more modest improvement in another 15 percent."

The trick is to figure out a Plan B if a patient doesn't respond to the drugs or develops untenable side effects.

"You have a plethora of genes involved in giving us what we call depression, and that will reflect altered levels of a number of different neurotransmitters," Tomb explains. People with depression related to levels of serotonin, for example, are more likely to respond to depression with anger and irritability, he says. "They're more likely to tear your head off than cry." Patients whose depression is related more to the neurotransmitter norepinephrine, on the other hand, are more likely to have no appetite and "stare out the window thinking grim thoughts."

Some patients may need a drug that is 60 percent a serotonin modulator, 40 percent norepinephrine, or vice versa, or some other combination; others may need a drug that is dopamine-based, or works on other neurotransmitters.

The art of psychiatry, he says, lies in understanding the subtleties of the depression, the drugs and the side effects. A depressed person who also suffers from anxiety, for example, may become more anxious on antidepressants, even though antidepressants help treat anxiety. The trick, Tomb says, is to "start low, go slow" with the dose. "This is where a lot of family doctors get into trouble." Some doctors, too, may not realize that an antidepressant takes at least three weeks to begin working, and sometimes that long for side effects to disappear. Some may not understand that patients need to be monitored closely, especially when first beginning a new drug or changing doses; or that patients going off a drug must do so very gradually.

"There's an amazing amount of psychiatry they don't track," he says about family physicians. Many times, "they're prescribing whatever the latest drug rep visiting their office is pushing."

This means, he says, that the doctors may not realize that sometimes the older tricyclics and MAO inhibitors might work better for some cases of depression, although they do need to be monitored very carefully. Younger psychiatrists also tend to avoid the older drugs, he says.

Because the patents for the tricyclics and MAO inhibitors ran out long ago, they cost "pennies a day" — another reason why drug salesmen don't push them, Tomb says.

About 8 percent to 10 percent of depressed patients don't respond to any antidepressant, he says. That's when he might add lithium or thyroid medication to the mix, or might try electroconvulsive therapy.

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