See related article by Laursen et al

Child Murder and Mental Illness in Parents: Implications for Psychiatrists

Filicide is the killing of a child by the parent. Studies have used different sample types and definitions of filicide, and many past studies have been fraught with methodological problems. National registries are exceptionally rich sources of data for studies of such rare phenomena due to a large sample size and potentially comprehensive information. However, national databases often provide limited data about the perpetrator. Rich psychiatric data are seldom included.

Laursen and colleagues1 compared homicide victimization rates of children whose parents were previously psychiatrically hospitalized with rates in the general population. They also compared risk across psychiatric diagnoses. To do this, they used 34 years of national registry data from Denmark. They were able to access police records for 6 years in order to quantify how frequently the perpetrator was a parent.

Of all 187 child homicide victims (not necessarily killed by their parent), 60 had a parent with a prior psychiatric admission. During the 6 years in which the authors could identify the perpetrator, 29 of 33 children (88%) were killed by a parent, 7 of whom had prior psychiatric hospitalizations. They found that in Denmark a child’s risk of becoming a homicide victim was significantly higher if the parent had been previously admitted to a psychiatric hospital. However, the absolute risk of homicide victimization only went from 0.009% to 0.051%.

Both the child’s age and parental mental health history were related to filicide risk. The relative risk was higher when the mother had previously been hospitalized rather than the father. Children whose mothers were diagnosed with schizophrenic or mood disorders were at higher risk than those whose mothers had other psychiatric diagnoses. Children under age 5 had the highest relative risk associated with maternal mental disorders. Younger children may be more likely to be at home during the day with the mentally ill mother, rather than at school as older children would be.

Caution must be used in making cross-national comparisons. Rates across nations differ substantially, possibly due to cultural and societal differences. The national registry data in this study were limited to severe mental disorders involving psychiatric hospitalization. Many parents with mental illness are managed on an outpatient basis. Also, psychiatric admission criteria vary across nations. The psychiatric admission diagnoses in the current study1 included drug abuse, which may be a less common reason for psychiatric hospitalization elsewhere.

Parents kill their children for 5 major reasons: fatal maltreatment, altruistic, acutely psychotic, unwanted child, and spouse revenge.2 Fatal maltreatment deaths occur as the end result of child abuse, neglect, or factitious disorder by proxy. This is the most common type of filicide. In altruistic cases, parents kill out of love, believing that death is in their child’s best interest (which can occur in psychosis or depression or terminal child illness). Parents who are acutely psychotic kill their child for no rational reason, such as in response to command hallucinations. Unwanted children may be killed because they are seen as a hindrance to the parent’s own goals. In spouse revenge filicide, one parent kills the child in order to severely emotionally wound the other parent.

The United States has the distinction of leading the world in infant homicide rates. In the few years since our analysis of maternal filicide studies,3 several investigators have utilized national-level data to examine a variety of dimensions of filicide. A recent study4 in England and Wales (N = 112) described a case series of persons convicted of infant homicide from 1996 to 2001. Data were collected from psychiatric court reports and mental health treatment teams. Over four-fifths (81%) of the infants were killed by their parents (fathers killed 50% and mothers 31%). One-quarter of the perpetrators evidenced symptoms of mental illness at the time, and one-third had a lifetime history of mental illness. Of the women who killed, 29% had a mood disorder, while more than half of the men had an alcohol or substance use disorder. The need for increased parenting support and perinatal psychiatric assessments was suggested.

Recently, parents who killed in Finland over a 25-year period (N = 200) were compared by reviewing medical, psychiatric, legal, and autopsy records from Statistics Finland.5 Finland’s rate of filicide was approximately 5 times higher than that of their Swedish neighbors. The mean age of victims killed by their mother was younger than that of those killed by their father. Fathers committed the act of filicide-suicide more frequently than mothers; this gender disparity was reversed for filicide alone. In forensic interviews, mothers reported high levels of stress and low levels of support.

Putkonen and colleagues6 also recently completed a register-based study of filicides (N = 124) in Austria and Finland from 1995 to 2005. They found that the bulk of the perpetrators were mothers. In 32% to 54% of cases, a suicide attempt or suicide occurred in conjunction with the filicide. Mood disorders (both psychotic and nonpsychotic) were frequently diagnosed, as were personality disorders and substance use disorders.

While many parents experience thoughts of child harm, filicide itself remains a rare occurrence. A prospective Indian study7 (N = 50) found that among severely mentally ill women admitted to a psychiatric hospital, 43% had infanticidal thoughts, 36% reported infanticidal behavior, and 34% reported both. Infanticidal behavior was associated with psychotic ideas about the infant, adverse maternal reaction to separating from the infant, and female infant sex (possibly for sociocultural reasons). Mothers with postpartum depression also commonly experience thoughts of harming their children. One study8 (N = 100) indicated that 41% of depressed mothers admitted to having such thoughts. Obsessive-compulsive distressing thoughts may occur comorbidly in mothers with postpartum depression and are ego-dystonic.9 This does not necessarily imply elevated risk. (This must be differentiated from a mother with ego-syntonic psychotic thoughts.) Again, while many mothers may have these thoughts, most do not act on them. Clinicians should be aware of such thoughts and not be afraid to inquire specifically.10

Although more research has been completed regarding mothers compared to fathers who kill their children, they have similar rates of filicide perpetration. A recent literature review11 found that fathers more often attempt or complete suicide after filicide. They often have multiple victims and may kill their spouse as well. Fathers, like mothers, may kill as part of chronic abuse or neglect, related to mental illness such as psychosis or depression, or as revenge against a former partner.

Further studies are needed in order to develop effective prevention strategies and programs. For example, while it may be shown that children are at greater risk of victimization when their parents have been psychiatrically hospitalized, the vast majority of parents who are mentally ill do not kill their children. What is it about certain parents and their interactions with their children that elevate the risk? The age of the child and the coping strategies and services engaged by the mother are important. Similar concerns are raised in the child welfare arena; of mothers and fathers who are reported for abuse, many “work their case plans” and are reunited without further harm. However, a subpopulation, with very similar risk factors, are reunited and go on to perpetrate serious violence or murder. There appears to be no “magic” factor in need of discovery. However, more research to further delineate which parents should cause psychiatrists and child protection the greatest concern would be valuable.

The current study by Laursen and colleagues, using national data, did not identify putative motives. Effective prevention strategies will differ according to motive. Although some parents kill in the throes of acute psychosis, many more kill due to chronic abuse and neglect. Research on parenting capacity is needed, along with systems research on how to make effective partnerships between mental health and child protective services.

When parents kill, a combination of risk factors appears to be more critical than any single factor. In addition to psychiatric history, risk factors may include violence history, victim characteristics, situational factors, social milieu, and demographics.3 Furthermore, there are many risk factors for violence and homicide other than mental illness. For example, in the United States, infants at elevated risk for homicide have young, poor mothers who sought prenatal care late.3

Laursen and colleagues found that those at highest risk of homicide victimization in Denmark were young children whose mothers were hospitalized because of schizophrenia or mood disorders. A parent’s history of prior psychiatric admission is a long-term static risk factor—one that cannot be altered. Dynamic risk factors, which can be modified to decrease risk, may include acute symptoms of mental illness, poor coping skills, the feeling of being overwhelmed, and poor parenting skills. In conclusion, we wish to emphasize that the vast majority of parents with mental illness do not kill their children.

Author affiliations: Department of Pediatrics (Dr Hatters Friedman) and Department of Psychiatry (both authors), Case Western Reserve University School of Medicine, Cleveland, Ohio.

Potential conflicts of interest: None reported.

Funding/support: None reported.

REFERENCES

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Submitted: September 7, 2010; accepted September 7, 2010

J Clin Psychiatry 2011;72(5):587–588 (doi:10.4088/JCP.10com06563).

Corresponding author: Susan Hatters Friedman, MD, Case Western Reserve University School of Medicine, Departments of Psychiatry and Pediatrics, Cleveland, OH 44106 (susanhfmd@hotmail.com).

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