Childhood maltreatment linked to risk of long-term depression and poor response to treatment
Individuals who experienced childhood maltreatment are twice as likely as those without a history of childhood maltreatment to develop both multiple and long-lasting depressive episodes, researchers at the Institute of Psychiatry (IoP) at King’s College London have found. The findings also show that maltreated individuals are more likely to respond poorly to pharmacological and psychological treatment for depression compared to non-maltreated individuals.
The results were presented by the authors at a press briefing at the Science Media Centre on Friday 12th August. The findings, published in the American Journal of Psychiatry, have emerged from a combined analysis of 16 epidemiological studies involving more than 20,000 participants and of 10 clinical trials involving more than 3,000 participants.
Depression is a major cause of mortality, disability, and economical burden worldwide and affects at least one in ten individuals in the UK at any one time. By 2020, depression is predicted to be the second leading contributor to the global burden of disease across all ages according to the World Health Organisation. The societal impact of depression is largely accounted for by individuals who develop multiple and long-lasting depressive episodes.
Dr Andrea Danese, senior investigator of the study at the IoP says: ‘Identifying those at risk of multiple and long-lasting depressive episodes is crucial from a public health perspective. The results of our study indicate that childhood maltreatment is associated both with an increased risk of developing recurrent and persistent episodes of depression, and with an increased risk of responding poorly to treatment.’
‘Therefore prevention and early therapeutic interventions targeting childhood maltreatment could prove vital in helping prevent the major health burden owing to depression. Knowing that individuals with a history of maltreatment won’t respond as well to treatment may also be valuable for clinicians in determining patients’ prognosis.’
One in ten children worldwide is exposed to maltreatment including psychological, physical or sexual abuse or neglect. Previous research has shown that maltreated individuals are more likely than non-maltreated individuals to show abnormalities in biological systems sensitive to psychological stress (such as the brain, the endocrine, and the immune system) both in childhood and in adult life, which could have important clinical implications.
Dr Danese continues: ‘The biological abnormalities associated with childhood maltreatment could potentially explain why in individuals with a history of maltreatment were found to be more likely than non-maltreated individuals to respond poorly to treatment for depression.’
Individuals with a history of maltreatment are at elevated risk of mental illness throughout their lives, but, in order to understand how early experiences bring about mental illness, future research should explore biological changes associated with maltreated in children, before accumulation of multiple depressive episodes.
Dr Rudolf Uher co-author of the paper, also at the IoP, says: ‘Our study has shown that antidepressant medication, psychological treatment and the combination of the two are less effective in those who have a history of childhood maltreatment. Whilst we still do not know exactly what type of treatment may improve the care of maltreated individuals, it may be that new treatments based on the biological vulnerabilities associated with childhood maltreatment could prove an exciting avenue for research.’
Previous research conducted by Dr Uher and colleagues, identified a common gene variant which makes individuals more sensitive to their environment in childhood, suggesting that biological, as well as environmental factors, play an important role in the long-term impact of childhood experiences.
The research was supported by the Medical Research Centre (MRC) Social, Genetic and Developmental Psychiatry (SGDP) Research Centre and the Department of Child and Adolescent Psychiatry, both at the Institute of Psychiatry at King’s College London. The authors are funded by the National Alliance for Research on Schizophrenia and Depression (NARSAD) Brain and Behavior Research Fund, the Italian Ministry of University and Scientific Research and the European Commission.
For full paper: Nanni et al., ‘Childhood Maltreatment Predicts Unfavourable Course Of Illness And Treatment Outcome In Depression: A Meta-Analysis’ is published in the American Journal of Psychiatry doi:
10.1176/appi.ajp.2011.11020335
For further information please contact Seil Collins, Press Officer, Institute of Psychiatry, King’s College London on seil.collins@kcl.ac.uk or 0207 848 5377