Does Abortion Cause Mental Health Problems?


Priscilla K. Coleman, Ph.D.

Bowling Green State University

I. Background for understanding causality when studying human behavior

Due to the inherent complexity of human psychological health outcomes, such as depression and suicidal behavior, identification of a single, precise causal agent applicable to all cases is not possible. Every mental health problem is determined by numerous physical and psychological characteristics, background, and current situational factors subject to individual variation. Further, any one cause (e.g. abortion) is likely to have a variety of effects (e.g., anxiety, depression, suicidal behavior) based on the variables involved.

A risk factor refers to any variable that has been established to increase the likelihood of an individual experiencing an adverse outcome. Risk factor data are used in medicine and psychology for the explicit purposes of understanding etiology, warning patients of risks associated with various medical interventions, and development of effective prevention and intervention protocols to maximize health.

Assessment of degree of risk is often expressed in terms of absolute risk, which relates to the chance of developing a disease over a time-period (e.g., a 10% lifetime risk of suicide) or in terms of relative risk, which is a comparison of the probability of an adverse outcome in two groups. For example, abortion would be considered an increased risk for suicide if the relative risk is significantly higher for women who abort compared to women who give birth or never have children.

Determination of causality technically requires an experimental design in which there is random assignment of large groups to expected cause conditions (e.g., abortion, no abortion/delivery, no abortion/no pregnancy). However, as is true with numerous variables of interest in psychology and medicine, it is not ethical nor is it practically feasible to implement such a study. When scientists are not able to control or manipulate the variable of interest, risk factors for negative outcomes are established over time through the two primary scientific steps described below.

1. Analysis of each individual study. Each individual study published in a peer-reviewed journal is examined to assess the quality of evidence suggestive of a causal link between abortion and negative outcomes. The following three criteria are applied when the variable of interest such as abortion can not be manipulated.

a. Abortion must be shown to precede the mental health problem (referred to as time precedence). This is typically accomplished with longitudinal or prospective data collection in which testing occurs over an extended period of time following the abortion.

b. Differences in abortion history (abortion, no abortion) must be systematically associated with differences in mental health status (covariation).

c. Finally, all plausible alternative explanations for associations between abortion and mental health must be ruled out using a method of control. Typically third variables predictive of both the choice to abort and mental health (e.g. income, previous psychological problems, exposure to domestic violence etc.) are statistically removed from the analyses. Identifying, measuring, and statistically controlling for known predictors of abortion would go a long way to help establish causality; however there are many other means for achieving the same goal of infusing control. Additional control techniques include: (1) matching groups on all variables known to be related to abortion and the outcome measures; (2) measuring potential confounding variables and introducing them as additional variables to assess their independent effects; (3) identifying and selecting homogeneous populations to draw the pregnancy outcome groups.

2. Integrative analysis. After evaluating individual studies for causal evidence linking abortion to decrements in mental health, scientists assess the consistency and magnitude of associations between abortion and particular mental health problems across all available studies. This integrative process represents the second step for determining whether or not abortion is a substantial contributing factor for severe depression and other mental health problems.

a. Consistency refers to repeated observation of an association between abortion and mental health across several studies using different people, places, and circumstances tested at distinct points in time. When results become generalized in this manner, the probability that an association would be due to chance is dramatically reduced.

b. Magnitude (or strength of effect) refers to whether the associations between abortion and various mental health problems are slight, moderate, or strong. Strong associations across various studies are more likely causal than slight or modest associations. This point has been illustrated with the high risk ratios for the association between exposure levels of smoking and incidence of lung cancer.

II. The tables below provide an overview of the studies related to abortion and suicide ideation and suicide, abortion and substance use/abuse, abortion and depression, and abortion and anxiety. The arrangement of the data in the tables offers guidance regarding the extent to which the conditions for causality have been met.

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Further analysis of APA report by Dr. Coleman