ALSPAC: Mental development in children
Subclinical psychotic episodes
A study looked at a range of factors that might be associated with subclinical psychotic episodes - possible warning signs of increased risk of schizophrenia in adulthood. Links were identified with impaired fetal growth, (ref 1) trauma at or around the time of birth, (ref 2) maternal smoking (ref 3) and events in childhood itself, such as bullying. (ref 4)
Toxin exposure
An association was found between binge drinking in mothers and behavioural problems such as hyperactivity at age four (in girls) and at age seven (in both sexes). (ref 5) They also identified a link between lead levels in blood at 30 months and a range of indicators at age seven to eight, including reading and writing ability, SATs results and antisocial behaviour measures, even at lead levels well below the generally recognised risk level. (ref 6)
Resuscitation at birth
Research looked at links between resuscitation at birth and cognition at age eight. As expected, infants with diagnosed brain damage were at risk of lower IQ, but so too were those who had been resuscitated but not identified as affected. (ref 7) Although the IQ differential was smaller, they are a much larger group overall.
Paternal depression
Paternal depression can affect children’s wellbeing. (ref 8) A comparison of the effects of prenatal and postnatal depression suggested that ‘environmental’ influences may be more significant than ‘biological’ factors.
Behaviour and genetic variation
Cohorts such as ALSPAC are particularly useful for studying the interaction between genes and environment, as a wide variety of 'lifestyle' data are collected and samples are available for DNA analysis. Two studies looking for links between behaviour and genetic variants affecting serotonin metabolism have generated contrasting results. Early life stress and MAOA-LPR interact to increase the risk of hyperactivity, (ref 9) but no effects were seen for a second variant, HTTLPR. (ref 10)
References
1. Association of measures of fetal and childhood growth with non-clinical psychotic symptoms in 12-year-olds: the ALSPAC cohort.
Thomas K, Harrison G, Zammit S, Lewis G, Horwood J, Heron J, Hollis C, Wolke D, Thompson A, Gunnell D. Br J Psychiatry. 2009 Jun;194(6):521-6.
2. Maternal tobacco, cannabis and alcohol use during pregnancy and risk of adolescent psychotic symptoms in offspring. Zammit S, Thomas K, Thompson A, Horwood J, Menezes P, Gunnell D, Hollis C, Wolke D, Lewis G, Harrison G. Br J Psychiatry. 2009 Oct;195(4):294-300.
3. Investigating whether adverse prenatal and perinatal events are associated with non-clinical psychotic symptoms at age 12 years in the ALSPAC birth cohort. Zammit S, Odd D, Horwood J, Thompson A, Thomas K, Menezes P, Gunnell D, Hollis C, Wolke D, Lewis G, Harrison G. Psychol Med. 2009 Sep;39(9):1457-67.
4. Prospective study of peer victimization in childhood and psychotic symptoms in a nonclinical population at age 12 years. Schreier A, Wolke D, Thomas K, Horwood J, Hollis C, Gunnell D, Lewis G, Thompson A, Zammit S, Duffy L, Salvi G, Harrison G. Arch Gen Psychiatry. 2009 May;66(5):527-36.
5. Binge pattern of alcohol consumption during pregnancy and childhood mental health outcomes: longitudinal population-based study. Sayal K, Heron J, Golding J, Alati R, Smith GD, Gray R, Emond A. Pediatrics. 2009 Feb;123(2):e289-96.
6. Effects of early childhood lead exposure on academic performance and behaviour of school age children. Chandramouli K, Steer CD, Ellis M, Emond AM. Arch Dis Child. 2009 Nov;94(11):844-8.
7. Resuscitation at birth and cognition at 8 years of age: a cohort study. Odd DE, Lewis G, Whitelaw A, Gunnell D. Lancet. 2009 May 9;373(9675):1615-22.
8. The effects of pre- and postnatal depression in fathers: a natural experiment comparing the effects of exposure to depression on offspring. Ramchandani PG, O'Connor TG, Evans J, Heron J, Murray L, Stein A. J Child Psychol Psychiatry. 2008 Oct;49(10):1069-78.
9. Early life stress, MAOA, and gene-environment interactions predict behavioral disinhibition in children. Enoch MA, Steer CD, Newman TK, Gibson N, Goldman D. Genes Brain Behav. 2010 Feb;9(1):65-74.
10. Effects of stressful life events, maternal depression and 5-HTTLPR genotype on emotional symptoms in pre-adolescent children. Araya R, Hu X, Heron J, Enoch MA, Evans J, Lewis G, Nutt D, Goldman D. Am J Med Genet B Neuropsychiatr Genet. 2009 Jul 5;150B(5):670-82.