Symptoms
 
 
 
Is Schizophrenia Associated With Aggression or Violence?
 
 
 
This is a difficult question to answer, primarily because of several confounding variables.  They include other behaviors and diagnoses that may coexist with schizophrenia and increase the risk for aggression.
 
It has been widely accepted that most people with schizophrenia are not aggressive or violent.  However, two studies suggest that this may not be true, especially in a group of people with schizophrenia that have the COMT (catech-O-methyltransferase) genotype.1
 
This study suggests that individuals with schizophrenia who have polymorphism of this genotype do have higher levels of aggression.  Polymorphism simply means more than one allele or gene.  Genotype is simply the genetic makeup of the individual.
 
Another study2 found that 75% of men and 53% of women demonstrated some form of aggression (verbal or other forms, or aggression against themselves or others) during a two year period.  Of these individuals, 17% of men and 26% of women attempted suicide.  In men, the number of hospitalizations and alcohol abuse were correlated with an increases risk.
 
It is clear that to understand aggression in schizophrenia we must make a distinction between aggression against one’s self and aggression toward others, since people who suffer from schizophrenia have a higher risk for suicide than people who do not have this disease.
 
Apart from these studies, we know that that aggression is more common in people with schizophrenia who are experiencing paranoid delusions or threatening auditory hallucinations.  This only makes sense, as these individuals are more prone to act out to protect themselves from this perceived threat.  It is also more common in patients who have a higher level of positive symptoms and who have less insight into their illness.
 
Structural brain damage, especially involving the frontal lobes increases this risk.  The frontal lobes are involved with inhibition.
 
Some co-morbid (or coexisting) psychiatric or medical conditions also increase this risk.
 
Psychiatric diagnoses that increase the risk for aggression in people with schizophrenia include:
 
  1. ADHD (Attention Deficit Hyperactivity Disorder)
  2.  
  3. Autism
  4.  
  5. Depression
  6.  
  7. Drugs (intoxication, withdrawal, abuse or dependence), particularly the use of alcohol, ecstasy and stimulants.
  8.  
  9. Intermittent Explosive Disorder
  10.  
  11. Other Mood Disorders (Mania or Schizoaffective Disorder)
  12.  
  13. Personality Disorders (Antisocial Personality Disorder and Borderline Personality Disorder)
 
There are some co-morbid medical conditions that also increase this risk:
 
  1. Alzheimer’s Disease
  2.  
  3. Epilepsy
  4.  
  5. Hypoglycemia
  6.  
  7. Menopause
 
There are also some medications and drug-drug interactions that increase the risk of aggression.  Most of these increase irritability, which may be why they influence the risk for aggression.
 
 
1Jones, G., Zamnit, S., Norton, N., et al British Journal of Psychiatry, 179, 351-355 (2001)
2Tilman Steiner, M.D.,Christian Wiebe, M.D., and Ralf Peter Gebhardt, Ph.D.  Psychiatr Serv 50:  85-90, 1999 (APA)
 
 
(Sources: The author’s knowledge base, unless otherwise noted.)
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Related Articles:
 
Symptoms
 
Motivation
 
Hallucinations and Other Misperceptions
 
Cognitive Impairment
 
Affect on Families
 
Schizophrenia and Alcohol Abuse or Dependence
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