Children and adolescents with parental mental illness (CAPRI) : prevalence, physical health, and social outcomes

Sammanfattning: Children and adolescents whose parents have mental illness (CAPRI) are a potentially vulnerable group. Previous studies showed that they are more likely to experience adverse mental health and social outcomes. However, studies investigating their physical health outcomes are scarce. Additionally, reliable estimates on the size of this group and their living conditions in contemporary Sweden is lacking. My thesis aimed to establish the prevalence of CAPRI in Sweden and to deepen our understanding of their physical health and living conditions. Five individual studies were conducted using linkage from various Swedish national registers. One of the studies was also conducted using data from English registers. In Study I, we estimated the prevalence of children and adolescents up to age 18 with parental mental illness in Sweden and determined the associations with various socioeconomic adversity. We found that around 9.5% of children had at least one parent with mental illness diagnosed within secondary care. The prevalence increased throughout the age and calendar year. These children were also more likely to experience a range of socioeconomic adversity, including having unemployed parents, being in a household that received social welfare benefits, or a household with the lowest income quintile. In Study II, we determined the associations between parental mental illness and the risk of childhood injury. We found that, overall, CAPRI had a higher risk of injuries compared to children without parental mental illness, especially during the first years of life. The increase in risk was slightly higher for children exposed to maternal, compared to paternal mental illness, and for rarer types of injuries (e.g., violence-related injuries) compared to more common types of injuries, such as falls. All types of parental mental illness were associated with higher risk, although the risk increase was slightly higher for more common mental disorders (e.g., depression and anxiety) compared to more serious mental illness (e.g., psychosis). In Study III, we determined the associations between parental mental illness and the risk of autoimmune diseases among the children. Parental mental illness was associated with a slight increase in the risk of autoimmune diseases in the offspring. However, the detailed picture was slightly more complicated. The highest risk was observed for type 1 diabetes among children exposed to maternal eating disorders. Additionally, exposure to parental common mental disorders was associated with a higher risk of juvenile arthritis, psoriasis, and type 1 diabetes. On the other hand, exposure to maternal psychosis and paternal alcohol/drug misuse was associated with a lower risk of coeliac disease and inflammatory bowel disease, respectively. In Study IV, we determined the associations between parental mental illness and the risk of childhood cancer, which is a relatively rare outcome. To increase statistical power, we pooled the estimates from Swedish and English national cohorts. Overall, we did not find enough evidence on the risk of cancer among CAPRI. However, results showed that maternal (but not paternal) psychosis was associated with a 25% reduced risk of childhood cancer, although confidence intervals for this estimation included the one and therefore this finding needs replication in larger studies. We also found borderline evidence of an increased risk associated with maternal alcohol/drug misuse, but no evidence of a change in risk associated with other types of parental mental illness. In Study V, we determined whether parental mental illness affected the likelihood of children being placed in out-of-home care and identified which factors might modify such likelihood. We found that CAPRI were more likely to be placed into out-of-home care, especially during the first years of life, compared to children without parental mental illness. While all types of mental illness diagnoses were associated with higher risk, the risk was particularly higher if the parents had a diagnosis of intellectual disability, alcohol/drug misuse, or non-affective psychosis, and if it was the mother who received the diagnosis compared to the father. CAPRI who also lived in lower socioeconomic positions were a subset with a particularly high likelihood of being placed in care outside of their homes. Overall, these findings showed that CAPRI are common in the contemporary Swedish population. They are more likely to experience adverse physical health outcomes, such as injuries and certain types of autoimmune diseases, but not cancer. They are also more likely to experience poor social outcomes, including socioeconomic adversity and being placed in out-of-home care. This information has important implications for services and public health. We need to maintain awareness of the circumstances in which children live and understand how best to support them and their families if we are to ensure their well-being and improve their life outcomes.