Research regarding the mental health effects of abortion has been
plagued by political controversy and selective reporting of results. One
frequently cited study in this field is an analysis of Danish medical
records which reported a 127% elevated risk of first-time treatment for
psychiatric disorders among women following a first induced abortion
(15.2 cases per 1000 person years, 95% CI: 14.4 to 16.1) as compared to
women having a first live birth (6.7 cases per 1000 person years, 95%
CI: 6.4 to 7.0). Despite this finding of higher rates of mental health
care following abortion, the authors concluded that abortion does not
increase the risk of mental illness based on their additional analyses
of first-time contact for psychiatric treatment in the nine months prior
to these pregnancy outcomes. Based on those analyses, the authors
concluded that the women who are most likely to have abortions were
simply at greater risk of first-time psychiatric treatment contact prior
to their abortions, and therefore the elevated rate of mental health
issues observed after abortion is simply an incidental continuation of
pre-existing mental health risks. In short, they suggested, women who
are predisposed to mental health issues are more likely than others to
have abortions. Therefore, their main finding of higher rates of mental
health disorders among aborting women, as compared to delivering woman,
can and should be ignored; abortion has no independent mental health
effects.
This study was widely criticized for several methodological issues. For
example, similar records-based studies of mental health treatment rates
before and after abortion had controlled for twelve months of prior
mental health whereas the Danish study inexplicably examined only nine
months. The selection of nine months prior to the pregnancy outcome also
meant that they were comparing women who carried to term during only the
time they were pregnant to women who had abortions who were only
pregnant for approximately two to three months prior to their abortions
and were not pregnant during the other six months. A better
methodological baseline, as used in other studies, would have been to
control for mental health history for a full year prior to conception of
the index pregnancy. Moreover, while the prior studies had excluded
women with a history of abortion from the control group of women who
carried to term, the Danish study included women with one or even
multiple abortions into the group of delivering women once they had a
first live birth. In other words, they were comparing women who had a
first abortion against a mixed group of women who had one or more
abortions prior to their first live birth, women who had miscarriages
prior to a first live birth, and women whose first pregnancy ended in a
first live birth. This admixture would clearly tend to obscure rather
than clarify the interpretation of their findings. A request sent to the
lead author (Munk-Olsen) for a breakdown of the number of first-time
mental health treatment cases in the delivery group based on prior
exposure to abortions by the author of this reanalysis was refused. In
my experience, that refusal was atypical. When I have made similar
queries of other authors, they have been quick to provide such
clarifications of their findings. An additional shortcoming is that
unlike prior studies, the Danish study failed to segregate their results
relative to inpatient and outpatient treatments, even though this would
have been an excellent way to distinguish between the severity of mental
illnesses. Yet another problem was that the researchers chose to exclude
women who died during the year following their pregnancy outcomes, which
is problematic since abortion is associated with increased rates of
suicide and deaths from other self-destructive behaviors, which are
clearly markers of psychiatric distress. Finally, in addition to using a
shorter pre-abortion period of investigation, the investigators limited
their post-abortion period to just one year. This was another step back
from the methodological strength of the prior record-linkage studies
that examined treatment rates over a period of four years following an
index pregnancy outcome. A longer period of follow up is important in
consideration of the literature indicating that the most severe
reactions to abortion can be delayed until after coping mechanisms are
exhausted and may be related to anniversary reactions and other triggers
such as a subsequent pregnancy. By limiting the investigation to one
year, the Danish research team would likely miss some of the reactions
associated with the one year anniversary, if they fell just outside the
anniversary date, in addition to any other delayed reactions.
The Danish researchers’ conclusions have also been called into question
by both prior studies which employed better methodologies, and
subsequent studies. For example, an analysis of the National
Longitudinal Study of Adolescent to Adult Health (Add Health) which
controlled 25 confounding factors, including prior mental health and
exposure to violence, found that each exposure to abortion increased the
risk of subsequent mental health disorders, a finding that could not be
explained by prior mental health. In addition, the subset of women who
reported aborting a wanted child experienced a 122% higher rate of
depression and a 244% higher rate of suicidality.
Two other studies, based on medical records of nearly 5,000 women
continuously covered by Medicare from the age of 16 forward, examined
mental health treatment rates both prior to and after each woman’s first
pregnancy outcome. These studies found that the change in the rate of
mental health treatments per patient per year from before to after a
first pregnancy outcome was highest among women who had abortions,
compared to both women who carried to term and women who had natural
losses. This was also true for both outpatient treatments and inpatient
treatments. It was also true relative to the length of hospitalization
for inpatient care, which is an excellent marker for a difference in the
severity and complexity of mental health issues.
Given the discontinuity between the Danish authors’ conclusions and the
findings of prior and subsequent studies of a similar nature, the
purpose of this reanalysis is to determine if the Danish data can be
reconciled with the direction of findings of other studies over the full
time period of the data presented.