The influence of nature in the form of genetics and nurture, or life events, on mental illness is more important than environmental events? Or is it? Research by Dr. Peter Kinderman, Professor of Clinical Psychology at the University of Liverpool, and colleagues find that traumatic life events have more impact on the likelihood of an individual being diagnosed with a mental health problem than a family history of mental illness.
Depression Diagnosis: The Research
Kinderman et al. set out to conduct “the first empirical, multivariate, test of the relationships between the key elements of the biospychosocial model of mental ill-health.” According to the authors, “biomedical approaches suggest that biological factors have a dominant position in the cause of mental health problems and thus they are the direct result of genes or gene-environment interactions.” 32,827 adult respondents answered an online questionnaire. The results seem to turn conventional ideas about mental illness upside down.
Participants, aged 18 to 85, volunteered to take an online questionnaire about their mental health and traumatic life events such as experiencing sexual abuse, physical abuse, and being bullied at school. In an exclusive interview with Decoded Science, Kinderman stated that they also studied other factors “like burglaries and divorce.”
The researchers did not examine some traumas, such as experiencing disasters like fires or major storms, currently listed in the Adult Needs and Strengths Assessment, the screening used by the states of Indiana and Texas and the City of San Francisco. The researchers collected demographic and social inclusion data along with information about mental health diagnoses and trauma.
Depression Study: The Results
The results found “life events (childhood abuse and bullying, and stressful life events in adulthood) were the strongest direct predictors of mental health problems (depression and anxiety).” A family history of mental illness came in second, but as the researchers point out, families transmit a culture as well as genetics. Additionally demographic and “social inclusion” factors also contributed to mental illness.
Dr. Kinderman and associates reported that the results supported what he hypothesized, that “individual differences in biology probably explain less than do different life experiences.” Or, in the development of a mental illness, nurture trumps nature.
Potential Cofounding Issues
As Kinderman noted in his interview with Decoded Science, the self-selection of the participants led to fewer very poor individuals participating. He stated, “The survey participants were slightly skewed to wealthier and better educated, but not significantly.” Those with the most severe mental illness, such as psychotic disorders, would probably be less likely to participate as well.
Depression Diagnosis: Understanding The Implications
The finding of the study has wide implications for the way in which funds could be best allocated to combat mental illness. If biological factors were paramount, spending money on drug research could be said to be the most important. If, as this research indicates, social factors such as physical, emotional, and sexual abuse are top contributors to mental health problems, then it makes more fiscal and practical sense to address these issues.
In fact, Kinderman is on record in, “The Role of the Psychologist in Social Change” advocating education about the importance of social factors in mental health. He writes, “We should acknowledge and help others understand the social determinants of human behaviour – how people’s behaviour is (at least in large part) shaped by social factors.” Drug companies may not agree.
Kinderman, P. et al., Psychological Processes Mediate the Impact of Familial Risk, Social Circumstances and Life Events on Mental Health. (2013). PLOS One. Accessed October 20, 2013.
Kinderman, P. The Role of the Psychologist in Social Change . (2013). Peter Kinderman. Accessed October 20, 2013.
Kinderman, P. The Role of the Psychologist in Social Change . (2013). The International Journal of Social Psychiatry. Accessed October 20, 2013.
Praed Foundation. Adult Needs and Strengths Assessment: An Information Integration Tool for Adults
with Behavioral Health Challenges, ANSA. Accessed October 20, 2013.