Comment: Prof Shirley Reynolds discusses a study linking depression and violent crimes
Release Date 25 February 2015
Professor Shirley Reynolds, Director of the University of Reading's Charlie Waller Institute for Evidence-Based Psychological Treatment, says we must be extremely cautious about how we interpret the study's results.
“This is an impressive study but we need to be extremely cautious about how we interpret the results. The study shows that very, very, few depressed people are convicted of violent crimes. Depressed people are more at risk of harming themselves than they are of harming anyone else.
“Misusing these results could increase the stigma associated with depression and other mental health problems, and the compassion we feel for the millions of people who have depression.
“It is also important to understand that this study shows an association between convictions and depression. Depression doesn’t cause convictions, convictions don’t cause depression. Many other factors can explain the association. These include previous traumatic experiences, including violence towards the self, poverty and social deprivation, and poor care as a child. The researchers in this study have done a very good job of controlling for some of these - but this can only ever be partially successful.
“Crucially, the study also showed that depressed people were more likely to be convicted of violent crimes. But this study does not show that depressed people committed more crimes. It means they were caught and found guilty more often than people who were not depressed. They may have committed fewer crimes or the same number of crimes. We just don’t know and these data can’t tell us.
"How is it possible that depressed people are convicted more often if they may not have committed more crime? Depression is associated with low motivation, hopelessness and apathy, sadness and feelings of guilt. It is more common in those who have lower incomes, are unemployed and are excluded from mainstream society. Therefore people who are depressed may be less motivated to avoid punishment, more hopeless and may feel that they deserve to be punished and are therefore less likely to try to avoid being caught.
“Second, when accused of a violent crime, depressed people may also be more likely to be charged of that crime. On average people who are depressed may make less effort to avoid punishment, and/ or may more readily admit to having committed an offence. Depression is also more common in those with lower incomes, less education and those who are unemployed. All of these things make it harder to get good legal advice and support and increase the change of being charged with an offence.
“Third, because they have less access to legal advice depressed people may also be more likely to be found guilty. Their low mood and lack of energy and motivation, their own guilt and expectation of punishment may add to the chance that a judge or jury will find them guilty.
“Finally, depressed people, may even be more likely to admit to offences which they did not commit because they feel guilty and deserving of punishment, and/ or they are more susceptible to pressure to confess.
“Despite these caveats this is an important piece of research. However it is imperative that we treat the results with care.”