For centuries the misconception that persons with mental illness are ticking time bombs, ready to explode into violence when jostled in the slightest, has wreaked enormous damage on their lives. This fear of violence accounts for a legacy of needless, neglectful institutionalization as well as the contemporary reluctance to accept group homes and other facilities in one's neighborhood. Periodically, the stigmatizing impact of equating mental illness with danger rears its head in the legal system, and when it does, the consequences can be just as unfortunate.

The latest evidence for this conclusion is the decision of the Rhode Island Supreme Court in Volpe v. Gallagher, a case that raised the issue of whether a parent can be held liable for the actions of an adult son with mental illness (+1). As in many cases involving questions of third-party liability, the facts are tragic. Sara Gallagher, the defendant in the case, owned a small house in North Providence, where she lived with her 34-year-old son, James Gallagher. In the words of the court, James Gallagher was "[a] jobless and practically friendless loner who was plagued by hallucinations, imaginary conversants, and a paranoid distrust of others." He lived in the basement of the house, where he kept, apparently for many years, a shotgun, a pistol, and assorted ammunition.

James Gallagher had once been hospitalized in a psychiatric facility for nine weeks and had been treated as an outpatient for a two-year period. It appears, however, that he had not been in treatment for a considerable period before the event that precipitated the lawsuit. His sister, a psychologist, characterized him as suffering from paranoid schizophrenia, a diagnosis consistent with the court's synopsis of his symptoms. Whatever his precise diagnosis, there is no question that on July 3, 1994, James Gallagher charged out of his basement with a loaded shotgun, which he discharged three times into Ronald Volpe, a neighbor who was trimming the hedge between their property, killing him.

On trial for first-degree murder, James Gallagher dropped his insanity defense, instead pled no contest to a reduced charge of second-degree murder, and was imprisoned. The victim's family then brought a wrongful death claim against Sara Gallagher, alleging that she had been negligent in allowing her son to store guns and ammunition on her property. At the trial of the civil case, the jury found for the plaintiffs, rejecting Sara Gallagher's defense that she did not know that her son was keeping arms in the house and, even if she had, that she could not have foreseen how they would be used. The trial judge, however, set aside the jury's verdict on the grounds that the absence of previous violence by James Gallagher rendered his murderous actions unforeseeable, and hence his mother could not have had a duty to prevent them. Plaintiffs' appeal of this order, which would have resulted in a new trial, brought the case before the Rhode Island Supreme Court.

Legal arguments in the appeal turned on the interpretation of a section of the Restatement of Torts, an authoritative compilation of common law principles in cases involving allegations of negligence or intentional harm. Suit was filed under Section 318 of the Restatement, which deals with the "Duty of possessor of land or chattels [that is, movable property] to control conduct of licensee." Although the language of the provision sounds a bit archaic to nonlegal ears, given its importance to the case it is worth quoting in part: "If the actor [that is, the future defendant] permits a third person to use land or chattels in his possession…he is, if present, under a duty to exercise reasonable care so to control the conduct of the third person as to prevent him from intentionally harming others…if the actor: (a) knows or has reason to know that he has the ability to control the third person, and (b) knows or should know of the necessity and opportunity for exercising such control."

Hence the plaintiffs argued that by virtue of Sara Gallagher's decision to permit her son to live in her house, she became liable for allowing him to retain weapons there, a breach of her duty to exercise reasonable care.

Justice Flanders wrote the majority opinion for the Rhode Island Supreme Court and quickly disposed of one of the two requirements on which a duty to exercise reasonable care is premised. He pointed to Sara Gallagher's assertions at trial—where she said that had she known the weapons were present, she would have insisted that her son get rid of them—as evidence that she had the ability to control her son's behavior. Moreover, he found that the jury in the case could reasonably have concluded from the evidence at trial that Sara Gallagher's denial of knowledge about the presence of the weapons was not credible. The remaining issue on which the case turned was the question of whether she knew or should have known about the necessity for exercising such control.

Here the court's view of the relationship between mental illness and violence came into play. Justice Flanders wrote that given Sara Gallagher's "knowledge of the 'peculiar' nature of [her son's] mental illness—in particular, the fact that he was paranoid, delusional, and prone to hallucinations—the jury was entitled to conclude that because she failed to put her foot down with respect to Gallagher's gun possession on her property, she thereby created an unreasonable risk of bodily harm to the victim and to others." Although it has never been clear exactly what led James Gallagher to murder Ronald Volpe, this view presumes that psychosis per se, perhaps particularly a paranoid psychosis, renders a person so likely to be violent toward others as to constitute a foreseeable risk that family members ignore only at their peril.

Of course, what the Rhode Island Supreme Court took for granted is far from confirmed by the literature on mental illness and violence. The largest prospective study ever done on the subject showed that just about every aspect of the presumption on which the court relied was incorrect (+2). In that study, persons with mental illness who did not abuse substances (there is no indication that James Gallagher had a substance abuse problem) were no more likely than their non-mentally ill neighbors to be violent. Moreover, among persons with mental illness who had been recently discharged from inpatient care, those suffering from schizophrenia were significantly less likely than those with other diagnoses to commit violent acts. Although some studies have suggested that paranoid thoughts are a risk factor for violence (+3,+4), two more recent studies, including the large-scale study cited above, have indicated that this hypothesis is not correct (+5,+6). Even hallucinations are not linked to violence, except perhaps for ones with specific commands to commit violent acts (+2). And even then, most hallucinatory commands are ignored or resisted by the person hearing them.

The best predictor of violent behavior remains a history of previous violence. This fact was precisely what Sara Gallagher argued in her own defense: given the complete absence of a violence history, she had no reason to anticipate that her son would ever harm another person. Whether or not she actually knew that the guns were in the house, it was agreed that James Gallagher had never discharged either weapon since obtaining them. But the Rhode Island Supreme Court rejected a "rigid adherence to a 'prior similar incidents' rule," preferring instead "to look to the totality of the circumstances in determining foreseeability." Unfortunately, the circumstances that the court considered were more reflective of societal prejudice than actual fact, perhaps best exemplified by its conclusion that "[f]or the victim, the victim's family, and the jury, one madman keeping loaded guns on defendant's property was one too many."

Beyond its impact on Sara Gallagher, the decision in Volpe may have much broader negative consequences, as noted by the sole dissenter, Justice Shea. Families often continue to care for children with mental illness well into adulthood, frequently constituting the best possible placement for them. Our social policies should be geared toward encouraging families to continue providing such care, not penalizing them for failing to anticipate their adult children's destructive behavior. As Justice Shea's dissent emphasized, "Parents are now faced with a weighty decision. Either they must reject their troubled children whose actions they are expected to control, or else face harsh legal consequences even in the absence of any previous incidents." To discourage families from providing care will, if anything, increase the risk of harm to persons with mental illness and to others.

Of course, Volpe is the law in Rhode Island alone at this point, and some other states' high courts, faced with analogous circumstances, have declined to impose liability (+7). The majority decision emphasized that it was limited to the facts of this case and that other situations might result in a different judgment. But the opinion's caution against "hasty extrapolations" belies the potential for extension of the decision to circumstances that involve arguably dangerous objects other than guns, to relationships other than that of a parent and child, and to situations in which the person with mental illness makes use of items belonging to the owner of the property. This bad decision can only get worse if it is used as precedent in subsequent cases.

It may sometimes seem as though prejudices against persons with mental illness are so deeply ingrained that we can only despair over the difficulty of eradicating them. However, the dangers of allowing mistaken notions about persons with mental illness—such as an imagined proclivity toward violence—to go unchallenged is that they can then become so much a part of social discourse that they find their way into decisions such as Volpe. That a state supreme court could evidence such misconceptions only underscores the importance of exposing everyone to the realities of mental disorders.

Dr. Appelbaum, who is editor of this column, is A. F. Zeleznik distinguished professor and chair in the department of psychiatry at the University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655 (e-mail, appelbap@ummhc.org).