Screening for post natal depression!

Sound like science fiction? Well I certainly agree however according to this report researchers have been delving into the finer components of post natal depression (PNG), to see if certain genetic parameters could predict the risk of mothers to PNG with some success.

 

I might have significant objections to peoples reliance on genetic testing to predict anything to do with poor mental health particularly in light of many reports whose findings have not been repeated; but from previous studies it is clear that genetic factors do play a part in people’s ability to maintain good mental health and as such need to be investigated. However I do feel that the results of such studies could be better reported to the general population who do not have access and aren’t interested in reading the full report (which can be purchased here ) 

I freely admit that I haven’t purchased this article as I find the fees somewhat exorbitant but I will point you to this page on the NHS website who have. I would love that people would go and look up where these newspaper reports come from but I am constantly reminded that frankly they don’t so better reporting really is the only answer. 

So PNG screening?

As an idea is a good one as between 10 and 15% of mothers will suffer from i tand with 706,248 live births (in 2009) this amounts to between 70,624.8 -105,937.2 mothers with PNG every year which is a hell of lot of mothers. (For more information on PNG please see or MINDs website )

However successful screening programs are reliant on good quality testing accurately predicting where it is likely to occur and preventative treatment given in good time. They are often limited by their ability to prevent the illness/disorder once the people at risk have been identified. The grandiose ideas of preventative treatment being given seems to fall foul of the advice given to mums, which suggests that actually unless the real and apparent risk is extremely high all that would happen is these women will receive specific attention from staff during their normal visits in regard to PNG symptoms, which as far as I can see amounts to good quality care being given to all and should already be happening.

  

This aside what does this article add?

There are many things and these a just a selection of what I felt where interesting (please see NHS for the others,)

A weak but statistically significant association was detected between one of the three genetic variants for the corticotrophin-releasing hormone receptor type 1 (CRH-R1) gene and postnatal EPDS scores. This suggests that this variant may be specific to postnatal depression only.

I.e. this factor is expected to only be seen in people with a high risk of PNG

There was a significant increase in the likelihood of being at risk for developing PND among women with two of the assessed genetic variants, with odds ratios (OR) ranging from 2.2 (95% confidence interval [CI] 1.2 to 6.9) to 4.9 (95% CI 2.0 to 12.0).

Odds ratios are one of several ways to summarise the association between an exposure and an outcome ie having the genetic variants and the risk of them getting PNG. So in this case with a confidence of 95% the women with two of the assessed genetic variants of the glucocorticoid receptor are between 2.2 and 4.9 times more likely to suffer PNG

Among women with specific variations on both the GR and the CRH-R1 genes, there was an even higher increase in the likelihood of being considered at risk for postnatal depression (OR 5.48, 95% CI 2.13 to 14.10), which researchers feel suggests that each variant contributes to PND risk independently.

In the other conclusions it was stated that the CRH-R1 receptor variants showed no significant increase in risk. So they concluded that as the risk was greater with both they have to work independently rather than in combination as these were not significant on their own.

However as the researchers did point drawing too many conclusions from their data, on its own, may be unwise and further research is required. 

First and foremost, for me at least is to consider a couple of the issues they brought up over diagnosis of PNG within the sample and the questionnaire completion rate which was 70%.

Firstly none of the women in this study were asked about having/suffering from PNG and it focused on risk of suffering from it when surely it would have been a good idea to follow up the research and see how many of the sample (controls as well as those with the variants) actually did/suffer from PNG.

Secondly the completion of both questionnaires was required for them to be included in the study and as the symptoms of PNG may have meant fewer of them completed the questionnaires the data may be skewed and not give an accurate picture anyway.

 

And as they themselves say

The researchers report that there were not enough participants in the study to "provide adequate power for all SNPs associations". They estimate that further research will need to involve approximately four times as many patients

Which sadly means that screening despite the report in the guardian that suggests it might be close, is in fact a long way off. 

However the findings are far from insignificant although in some ways I would wish that journalists would not report on such findings without referring to the source article a bit more than they are currently in the habit of doing as it is often extremely misleading and people are not in the habit of following up stories in search of a better understanding.