Online Coverage from the 150th Annual Meeting
of the American Psychiatric Association
May 18 - 21, 1997
© 1997 Medscape, Inc.

Trends in Violence and Aggression

Speaker: Trey Sunderland, MD
Reporter: Jeff Hanissian, MS-IV at the University of Pennsylvania Medical School

Introduction

Whether patient, victim, or caregiver, the ubiquitous problems of violence and aggression seem to touch us all. There are 51.5 violent crimes committed annually for every thousand US residents over the age of 12, and 24,500 murders and 30,900 suicides take place each year in this country, according to Dr. Trey Sunderland, Chief of the Geriatric Psychiatry Branch of the National Institute of Mental Health. The settings for these violent acts are many, and include prisons, half-way houses, outpatient clinics, hospitals (both medical and psychiatric), homes, and nursing homes.

Revealing Statistics

While violence is commonly -- and even reflexively -- associated with youth, the elderly are also significantly affected. The elderly comprise 12% of the population- 4.6% are murder victims and 1% are murderers. Dr. Sunderland said he had suspicions that the surprisingly high rate of injury among nursing home workers may be due, in part, to violence by the elderly patients against their caregivers. Indeed, the injury rate in nursing home workers is higher than even that seen in construction workers.

The epidemiology of violence is remarkably skewed when divided along lines of gender, race, and age. For example, 90% of all homicides are committed by males, making men 10 times more likely to kill than women. Suicide, however, is only 4 times more common in men, with an 80/20 split. Only a minority of murderers are psychiatric patients, and murder by the elderly is rare. However, both groups are over represented in the suicide statistics -- over 90% of suicide victims carried an Axis I diagnosis, and suicide in the elderly is disproportionately frequent.

Psychiatric Diagnoses Associated with Violence

Some psychiatric conditions are strongly associated with violent, aggressive, or agitated behavior. For example, 12 to 15% of schizophrenic patients are violent. Of this group, 90% show positive signs, and many are paranoid schizophrenics. Other examples of conditions associated with violence are:

Organic brain disorders including dementia delirium, brain injury, seizures, and mental retardation;
Mood disorders including mania, depression, and mixed states;
Personality disorders including antisocial, borderline, and intermittent explosive personality disorders; and
Miscellaneous disorders including anxiety disorders, substance abuse, and attention deficit disorder.

Genetic Studies

Studies looking at the genetic basis of violence have revealed that levels of the serotonin metabolite 5-HIAA are significantly elevated in the cerebrospinal fluid (CSF) of violent offenders. The pattern is especially notable in non-impulsive alcoholic offenders, compared with alcoholic offenders diagnosed with antisocial personality and intermittent explosive disorder (and compared with normal subjects). Interestingly, suicidal study subjects showed lower CSF 5-HIAA concentrations at a statistically significant level.

In the same study on alcoholic offenders, those with antisocial personality disorder were found to have high mean CSF testosterone levels. In both cases, however, overlap in the levels across all groups preclude these trends from having diagnostic utility.

In animal and human studies, genetic analysis has shown that polymorphism of the tryptophan hydroxylase gene is predictive of both CSF 5-HIAA levels and predisposition toward impulsive behavior and suicide. In animal studies, 5-HT1b "knockout" mice showed more aggressive response to intruder mice. In humans, an association between UU genotype at the polymorphic tryptophan hydroxylase allele and high CSF 5-HIAA levels in impulsive subjects, compared with non-impulsive and control subjects with the UU genotype has been noted. An association between the LL genotype and low CSF 5-HIAA levels in impulsive subjects, compared with non-impulsive and control subjects with the LL genotype, was also shown. With regard to suicide, UU subjects are less likely to be suicidal and LL subjects are more likely.

These trends hold true in female Macaques as well. High CSF 5-HIAA levels were associated with higher incidence of fighting, but also with lower social dominance ratings. The monkeys with high CSF 5-HIAA levels were more likely to fight but less likely to be successful in the social structure.

Levels of cortisol, serotonin, and norepinephrine, in addition to 5-HIAA and testosterone, have also shown statistically significant trends in those prone to violent and aggressive behavior like fire setting, homicide, and self-destructive behavior.

Violence, as defined by the panel of experts presenting at this symposium on violence and agitation, is the exertion of any physical force so as to injure or abuse another person or thing. Panel members defined aggression as hostile action or threat directed toward others. That action or threat may be verbal, physical, vocal, or sexual. Agitation was defined as excessive motor activity that is usually nonproductive and repetitive (e.g., pacing, fidgeting, wringing hands), and associated with a feeling of inner tension.

Several psychiatric diagnoses have components of violence and agitation. While much of the research into the genetics of violence is immature, understanding of these behaviors is growing, with resultant improvements in both pharmacologic and nonpharmacologic interventions in violence and agitation.

Reference:

Sunderland T. Treatment of the elderly suffering from psychosis and dementia. Journal of Clinical Psychiatry. 57 Supp 9:53-6, 1996

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