Article 5: Violence

Question 1

In the study on the examining violence in people with SZ how did they select the patients and who were the controls?

Answer 1

• Studying a population from Sweden (8000)
• Had good medical and criminal records
• Had been diagnosed 2x
• There was a subgroup of people with SZ who had an unaffected sibling
• Wanted to be able to consider familial effects – both of genes and early environment
• Substance abuse diagnosis less reliable than other diagnostic information
  (Control group: Matched controls from the general population)

Question 2

What were the main findings from the study of violence in schizophrenia?

Answer 2

This study had two main findings:

(1) The only instance where there is an association between psychosis and violent crimes is when the patient also has a substance abuse comorbidity diagnosis.
(2) The risk for violence varied depending on the degree of relatedness to the patient with psychosis.

Question 3

Why was it important to have family members as controls?

Answer 3

It was important to have family members as controls to account for family confounding, which means taking into account the interaction between the genetic predisposition and the early environment.

Question 4

What additional information did this give?

Answer 4

This additional information gives us four possible explanations as to why there is an increased risk for violence in individuals with SZ compared with the general population. Those four explanations are:

(1) SZ may lead to substance use which increases the risk for violence.
(2) A genetic predisposition to substance abuse may lead to psychosis (SZ) which increases the risk for violence
(3) There may be an association between a genetic predisposition to SZ and substance abuse and then to violence.
(4) There may be a genetic predisposition to all three components; substance abuse, SZ and violence (i.e committing violent crimes).

Question 5

To sum up, what were the results for the study on violence? (class notes)

Answer 5

Comorbid substance abuse substantially increases risk of violence in SZ
Increased risk is smaller compared to siblings
Siblings have higher rates of substance abuse, suggesting a familial contribution to all three problems

Other notable findings:
Time from release to offense: ≈ 3 years
Greater risk when substance abuse onset was after SZ diagnosis
Implications for treatment
Also for stigma