The researchers hope that their findings could lead to the development of inexpensive cognitive tests to screen for these common emotional and mental health illnesses, particularly in people identified as being at high social and genetic risk. Such tests could facilitate early intervention, which has proven to be one of the most effective ways of combatting mental illness.
Professor Ian Goodyer from the University of Cambridge, who led the study, explains: “Whether we succumb to anxiety and depression depends in part on our tendencies to think well or poorly of ourselves at troubled times. How it comes about that some people see the ‘glass half full’ at times of stress and think positively, whereas others see the ‘glass half empty’ and think negatively about themselves, is not known.
“The evidence is that both our genes and our early childhood experiences contribute to such personal thinking styles. Before there are any clinical symptoms of depression or anxiety, this test reveals a deficient emotional understanding in some teenagers – a biomarker for the lack of resilience that leads to mental illnesses.”
People who carry a particular version of a gene that encodes a protein involved in regulating levels of serotonin, a chemical linked to mood and feelings of happiness, are more likely to experience anxiety or depression. Similarly, young people who have been exposed to adverse family environments in early childhood, such as parental conflict or neglect, are also at increased risk.
For the study, young people aged between 15 and 18 underwent genetic testing and environmental assessment, an exercise that would currently be too expensive and take too long to use as a widespread method of screening for mental health problems. The participants were then given computer tests to gauge how they process emotional information.
One of the tests asked the participants to evaluate whether words were positive (e.g. ‘joyful’), negative (e.g. ‘failure’) or neutral (e.g. ‘range’). A separate test measured their responses to negative feedback.
The results reveal that those adolescents with the version of the gene linked to depression who had also been exposed to family arguments and violence before the age of six had difficulty evaluating the emotional tone of words. Previous research has associated a maladjusted perception and response to emotions, as seen here, with a significantly increased risk of depression and anxiety.
Dr Matthew Owens from the University of Cambridge added: “Having difficulty in processing emotions is likely to contribute to misunderstanding other people’s intentions and can make individuals emotionally vulnerable. This research opens up the possibility of identifying individuals at greatest risk and helping them with techniques to process emotions more easily or training them to respond more adaptively to negative feedback.”
One in four people in the UK will experience a mental health problem in the course of one year. Adolescence is a crucial period for the development of depression, and mental health problems are also common in young people. Approximately 10 per cent of children aged 5-16 in Great Britain are assessed as having a mental disorder of some kind, including conduct disorder, emotional disorder or hyperactivity.
Professor Barbara Sahakian, a coauthor on the paper from the Department of Psychiatry at the University of Cambridge, said: “The way we perceive and respond to emotions affects our resilience and whether we succumb to depression and other maladaptive ways of thinking. Using the biomarkers identified in this study, it is possible to develop a screening programme to identify those at greatest risk.”
The research, published online in the journal PLOS ONE, was funded by the Wellcome Trust, the National Institute of Health Research, and Cambridgeshire and Peterborough Collaborations for Leadership in Applied Health Research and Care.
Image credit: John Wildgoose, Wellcome Images.
Owens M et al. 5-HTTPLPR and early childhood adversities moderate cognitive and emotional processing in adolescence. PLOS ONE 2012 (epub ahead of print).