The Risk of Schizophrenia and Child Psychiatric Disorders in Offspring of Mothers with Lung Cancer and Other Types of Cancer: A Danish Nationwide Register Study

Abstract

BackgroundMaternal immune responses and brain-reactive antibodies have been proposed as possible causal mechanisms for schizophrenia and some child psychiatric disorders. According to this hypothesis maternal antibodies may cross the placenta and interact with the developing CNS of the fetus causing future neurodevelopmental disorders. Therefore, we investigated if children of mothers with cancer might be at higher risk of developing psychiatric disorders, with particular focus on small-cell lung cancer, which is known to induce production of antibodies binding to CNS elements.MethodsNationwide population-based registers were linked, including the Danish Psychiatric Central Register and The Danish Cancer Registry. Data were analyzed as a cohort study using survival analysis techniques. Incidence rate ratios (IRRs) and accompanying 95% confidence intervals (CIs) were used as measures of relative risk.ResultsIn general, parental cancer was not associated with schizophrenia in the offspring (IRR, 0.98; 95% CI, 0.95-1.01). Furthermore, we found no temporal associations with maternal cancer in general; neither around the pregnancy period. However, maternal small-cell lung cancer increased the risk of early-onset schizophrenia and maternal small-cell lung cancer diagnosed within 20 years after childbirth increased the risk of schizophrenia. Parental cancer was not associated with child psychiatric disorders (IRR, 1.01; 95% CI, 0.98-1.05) except for the smoking related cancers. There was a significantly increased risk of child psychiatric disorders in offspring of both mothers (IRR, 1.35; 95% CI, 1.16-1.58) and fathers (IRR, 1.47; 95% CI, 1.30-1.66) with lung cancer of all types.ConclusionsIn general, parental cancer did not increase the risk of schizophrenia nor of child psychiatric disorders. However, maternal small-cell lung cancer increased the risk of schizophrenia in subgroups; and lung cancer in general increased the risk of child psychiatric disorders, which could be due to risk factors associated with parental smoking.

Mental disorder diagnoses of offspring affected by parental cancer before early adulthood: the 1987 Finnish Birth Cohort study

“…Our study found no evidence of increased levels of hospital‐treated psychiatric disorders in children affected by parental cancer. Previous research has presented similar findings .…”

Clinical studies of neuroinflammatory mechanisms in schizophrenia

“…Severe infections and autoimmune disorders over a lifetime appeared to confer additive risk for schizophrenia and schizophrenia spectrum disorders (Benros et al, 2013b;Meyer, 2011). In contrast, parental infection alone did not appear to be a definitive risk factor (Benros et al, 2013a(Benros et al, , 2013b. These data suggest that systemic infections might impact the developing fetal brain, making it vulnerable to brain illnesses later in life (Ellman et al, 2009).…”

Parental hospital‐treated somatic illnesses and psychosis of the offspring—The Northern Finland Birth Cohort 1986 study

“…In a large nationwide Danish cohort study, the authors concluded that parental cancer was not associated with schizophrenia of the offspring. In their study, maternal small cell lung cancer was found to be positively related to the onset of schizophrenia in the offspring, but the finding was explained by parental smoking, a well‐recognized risk factor for mental health (Benros, Laursen, Dalton, Nordentoft, & Mortensen, ). Similarly, a nationwide Finnish birth cohort study did not find an association between parental cancer and psychosis in the offspring followed up to age 21 (Niemela et al, ).…”