The behavioural origin of schizophrenia

Figure 6 is a graphical presentation of the proposed behavioural epigenetic basis for the development of schizophrenia (click on image for pdf).

As the brain is plastic it is affected (through epigenetic change) by abuse or abnormal behaviour (1, 2) (Fig 4). For instance, childhood abuse (sexual, extreme physical or extreme neglect) (2) is a high risk for suicide because of increased methylation of the glucocorticoid receptor (GR) receptor in the hippocampus (1, 2) . Sexually abused young people were at an increased risk of developing psychosis/schizophrenia compared with the rest of the population (3, 4) . Rates reported were: 10 times more at risk of receiving a diagnosis of a psychotic disorder, including 7 times the risk of being diagnosed as schizophrenic compared with youth from the general population (3) and that penetration led to 3.4% times for psychosis and 2.4% schizophrenia (3).

Also, schizophrenics are around 10 times more likely to take their own lives than the general population (5, 6) , different types of study report different data but generally the suicide rate among schizophrenics is much higher than that for the general population (7) . A case study (8) showed that suicide can also be a risk for a schizophrenic abuser (8) .

 

References

1. Labonte B, Yerko V, Gross J, et al. Differential glucocorticoid receptor exon 1(B), 1(C), and 1(H) expression and methylation in suicide completers with a history of childhood abuse. Biol Psychiatry 2012;72(1):41-8. doi: 10.1016/j.biopsych.2012.01.034 [published Online First: 2012/03/27]

2. McGowan PO, Sasaki A, D'Alessio AC, et al. Epigenetic regulation of the glucocorticoid receptor in human brain associates with childhood abuse. Nat Neurosci 2009;12(3):342-8. doi: 10.1038/nn.2270 [published Online First: 2009/02/24]

3. Bourgeois C, Lecomte T, Daigneault I. Psychotic disorders in sexually abused youth: A prospective matched-cohort study. Schizophr Res 2018 doi: 10.1016/j.schres.2018.03.020 [published Online First: 2018/03/20]

4. Cutajar MC, Mullen PE, Ogloff JR, et al. Schizophrenia and other psychotic disorders in a cohort of sexually abused children. Arch Gen Psychiatry 2010;67(11):1114-9. doi: 10.1001/archgenpsychiatry.2010.147 [published Online First: 2010/11/03]

5. Kasckow J, Felmet K, Zisook S. Managing Suicide Risk in Patients with Schizophrenia. CNS drugs 2011;25(2):129-43. doi: 10.2165/11586450-000000000-00000

6. Bornheimer LA. Moderating effects of positive symptoms of psychosis in suicidal ideation among adults diagnosed with schizophrenia. Schizophrenia research 2016;176(2-3):364-70. doi: 10.1016/j.schres.2016.07.009

7. Hor K, Taylor M. Suicide and schizophrenia: a systematic review of rates and risk factors. Journal of Psychopharmacology (Oxford, England) 2010;24(4_supplement):81-90. doi: 10.1177/1359786810385490

8. Soron TR. A Case Report on Management of Father Daughter Incest with Schizophrenia. Case Reports in Psychiatry 2016;2016:4010187. doi: 10.1155/2016/4010187