Last month Senators Robert Menendez (D-NJ) and Richard Durbin (D-IL) announced the introduction of the MOTHERS Act into the Senate. From Menendez’ site the goal of the legislation is “to better increase education and access to screenings for new mothers and to increase research into this difficult illness.” Sounds like a good enough goal but when you start to look at the effects of the legislation it is easy to see that this is a bad idea!
The legislation will begin a screening program for birthing mothers for postpartum depression (PPD), this is the crux of why this is a bad idea. A look into screening tests will expose why this is a bad idea. I’m pulling this right off of wikipedia in order that everyone can look at where I got the numbers and the reasoning. Using a Bayesian analysis I’m going to examine a drug test that is 99% sensitive and 99% specific. Assuming (from case studies and cohort designs) that the prevalence of using this drug is 0.5%. Based on Baye’s theorem the probability that a person who tested positive for the drug is actually a drug user is 33%. So it is actually more likely that a positive result is a false positive and that the person isn’t a drug user.
Now apply this to a screening tool for a whole demographic of our nation, pregnant women. Just as we’ve seen with breast cancer screening, false positives become a huge problem in a massive screening system like this. After 3 mammograms, 18% of women will have false positives, after 10 tests the rate rises to 49.1% of women who will have a false positive. So are we willing to put a quarter of our expectant and newly birthed mothers on psychotropic drugs? Recently we’ve seen the powerful side effects of many of these drugs with the FDA black boxing Chantix and Wellbutrin.
Dr. Doug Bremner, who is outspoken about the need to recognize the over-medication of psychiatric illnesses has commented extensively on this issue at Before You Take That Pill. He makes excellent points about populations that we KNOW have an increased risk for PPD, expectant mothers with previous depressive issues or PTSD.
What baffles me is that this may be the largest population in the US to see a physician multiple times in a year. It seems that an OB/GYN or PCP would be able to assess the risk of a depressive issue and fully cover the patient history in the 9 month lead-up to the birth. Talk about an effective screening tool! It should be easy enough to identify those mother’s who truly are at risk and provide them with the necessary social and psychological resources in order to prevent any PPD episodes that they may be at risk for.
As with any marginally at risk population, the effects of massive screening will convey a huge number of false positives and be an absolute boon to the pharma industry, they’re about to be able to put millions of people on anti-depressives that would have never even been in a candidate population.