The December 2008 issue, with its original papers by Fergusson et al,1 Dingle et al2 and its commentaries,3 was of great interest to us. Fergusson et al have overcome some of the methodological problems of previous studies.4 Nevertheless, their latest study has weaknesses: the womens’ abortion status is not verified objectively, only by self-report. There were 153 abortions in 117 women but insufficient data to distinguish the effects of differing numbers of abortions; it is known that women having more than one abortion may differ in many respects from those having a single abortion.4 Also, because of the relatively restrictive law in New Zealand – ‘ continuance of the pregnancy would result in serious danger... to the... mental health of the woman’ – some selection bias may have been in operation, allowing only women with more traumatic histories to access abortion. We will not discuss the Dingle et al paper, as its failure to account for pregnancy intention (wantedness and timing) in those giving birth means that the comparator is inappropriate.5

The Royal College of Psychiatrists’ Position Statement of 14 March 2008 mentions that a full systematic review is needed. This has now been done.5 Only four studies fell into the authors’ ‘good evidence and low risk of bias’ category. All four studies showed a neutral effect of abortion on mental health, indicating no significant differences between the study comparison groups. So Fergusson et al’s study can be regarded as the first good-quality study to show a possible negative effect when attempting to answer the question: what is the relative risk of mental health problems for women who chose abortion compared with those who chose to have a live birth and who reported that the pregnancy was unwanted/initially distressing?

As clinicians working in the field of sexual and reproductive health, we favour the approach of Oates et al.3 We are supportive of their idea that abortion is not a psychiatric issue and that the Royal College of Psychiatrists should not develop a guideline on abortion. We would never want to go back to the psychiatric referral hurdle-jumping situation before and immediately after the Abortion Act came into force.6 The adverse effects of denied abortion must never be forgotten.7 Nevertheless, we do value working in partnership with mental health teams for the benefit of certain women requesting abortion who have a history of mental health problems or persistent ambivalence.

Whether abortion causes harm to women’s mental health is a question that is not scientifically testable, as women with unwanted pregnancies cannot be randomly assigned to abortion v. abortion denied groups.7 It seems inappropriate therefore for Casey to talk of potential litigation against abortion providers for failing to provide information on a possible causal link between abortion and subsequent mental health problems.3 All women should have rights to reproductive health and self-determination, of which safe and dignified access to abortion services is an important part.8