Battered wife syndrome is a recognized psychological condition to describe a woman who, because of constant and severe physical abuse by a male partner, becomes depressed and unable to take any independent action that would allow her to escape the abuse. The condition explains why abused women often do not seek assistance from others, fight their abuser, or leave the abusive situation. Sufferers have low self-esteem, and often believe that the abuse is their fault. Such women usually refuse to press charges against their abuser, and refuse all offers of help, often becoming agressive or abusive to others who attempt to offer assistance. Although the condition usually affects women, children and more rarely men can also exhibit the syndrome.

More controversially, continual abuse has been used, at law, as a defence for abused persons who subsequently attack or kill the abuser, or engage in violence or sexual abuse against others at the behest of the abuser. However, there is no consensus in the medical profession that such abuse results in a mental condition severe enough to reach the legal standard of insanity required under the McNaghten rule - that the abused person was incapable of distinguishing right from wrong when they committed the offence. In fact, many psychologists and psychiatrists believe that a person who meets the clinical definition of battered wife syndrome would simply be mentally incapable of either attacking their abuser, or attacking another at the behest of the abuser.

In the trial of serial killer Paul Bernardo, the prosecution called an expert witness to testify that Paul's wife Karla Homolka could have been suffering from battered wife syndrome when she participated in the murders of Kristin French and Leslie Mahafey. In Bernardo's appeal to the Ontario Court of Appeal, the court considered Bernardo's request to reverse the conviction on the basis that this evidence was improperly admitted, as the expert had not examined Homolka and that Homolka exhibited behavior that was inconsistent with the syndrome, such as displaying an enthusiastic attitude. Although the court found merit in the argument, they ruled the admission of such evidence did not have an effect on the overall result of the trial and affirmed the convictions.