Childhood adversities have additive effect on psychiatric disorder onset
MedWire News: Childhood adversities (CAs) have significant subadditive associations with the onset of psychiatric disorders throughout the life course, a US study has found.
Previous studies demonstrating significant associations between CAs and adult psychiatric disorders have largely examined single CAs. As CAs are highly clustered, this has led to an overestimation of the importance of individual CAs.
To determine the best multivariate model for associations between retrospectively reported CAs and first onset of psychiatric disorders, a team led by Ronald Kessler (Harvard Medical School, Boston, Massachusetts) analyzed CAs and lifetime Diagnostic and Statistical Manual of Mental Disorders-IV disorders assessed in the US National Comorbidity Survey Replication involving 9282 adults.
CAs proved to be highly prevalent and inter-correlated, with 53.4% of respondents reporting at least one CA, and 95.1% of those with parental neglect reporting multiple CAs. The researchers identified a maladaptive family functioning (MFF) cluster of CAs that correlated most strongly with mental health disorder onset. This cluster included parental mental illness, substance abuse disorder, and criminality; family violence; physical abuse; sexual abuse; and neglect. The best fitting multivariate model included terms for each type of CA, number of MFF CAs, and number of non-MFF CAs.
Multiple MFF CAs had significant subadditive associations with disorder onset. There was little specificity for particular CAs with particular disorders. Associations declined in magnitude with life course stage and number of previous lifetime disorders but increased with length of recall.
Using the best-fit model to calculate population attributable risk proportions, the researchers found that 44.6% of all childhood-onset psychiatric disorders and 25.9% to 32.0% of later-onset disorders were attributed to CAs.
Writing in the Archives of General Psychiatry, the researchers note: “The fact that associations increased with length of recall raises the possibility of recall bias inflating estimates.”
They conclude: “The multivariate structure of the associations between CAs and disorder onset is broadly subadditive… This subadditive pattern has important implications for intervention because it means that prevention or amelioration of only a single CA in youths exposed to many CAs is unlikely to have important preventive effects.”
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By Joel Levy