In The Politics of Autism, I discuss various ideas about what causes the condition. Studies have ruled out vaccines as a cause of autism, but there is a very long and growing list of other correlates, risk factors, and possible causes that have been the subject of serious studies. This blog has identified at least 41 such items. Here is yet another:
Background
Roughly more than one in six adults worldwide suffer from psychiatric conditions. Sporadic studies have associated parental psychiatric disorders with autism spectrum disorder in offspring. Comprehensively examining the association between parental psychiatric disorders and offspring autism spectrum disorder is needed to guide health policies, and to inform etiologic studies.
Methods
We included all children born in Sweden and Finland 1997–2016. Diagnoses were clinically ascertained from National Registers through 2017. We calculated adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for autism spectrum disorder in offspring of fathers and mothers with psychiatric disorders, in both parents jointly and across co-occurring conditions.
Findings
Among 2,505,842 children, 33,612 were diagnosed with autism spectrum disorder, of which 20% had a parent with psychiatric disorders. The risk of autism spectrum disorder was increased across all psychiatric disorders in fathers (Sweden: aHR = 2.02, 95% CI = 1.92–2.12; Finland: aHR = 1.63, 95% CI = 1.50–1.77), mothers (Sweden: aHR = 2.34, 95% CI = 2.24–2.43; Finland aHR = 2.12, 95% CI = 1.92–2.28), or both parents (Sweden: aHR = 3.76, 95% CI = 3.48–4.07; Finland aHR = 3.61, 95% CI = 3.20–4.07), compared to neither parents. Co-occurrence of parental psychiatric disorders further increased risk (e.g., Sweden: for one, two or ≥three different diagnostic categories compared to no diagnosis, in fathers aHR = 1.81, 2.07, 2.52; in mothers aHR = 2.05, 2.63, 3.57).
Interpretation
Psychiatric disorders in both parents conveyed the highest risk of offspring autism spectrum disorder, followed by mothers and then fathers. The risk increased with number of co-occurring disorders. All parental psychiatric disorders were associated with increased the risk of autism spectrum disorder. To reliably assess the risk of autism spectrum disorder in children, a comprehensive history incorporating the full range of parental psychiatric disorders is needed beyond solely focusing on familial autism spectrum disorders.
The very long. growing, and probably incomplete list of other correlates, risk factors, and possible causes that have been the subject of serious studies:
- Inflammatory bowel disease;
- Pesticides;
- Air pollution and proximity to freeways;
- Maternal thyroid issues;
- Autoimmune disorders;
- Induced labor;
- Preterm birth;
- Fever;
- Birth by cesarean section;
- Anesthesia during cesarean sections;
- Maternal and paternal obesity;
- Maternal diabetes;
- Maternal and paternal age;
- Grandparental age;
- Maternal post-traumatic stress disorder;
- Maternal anorexia;
- Smoking during pregnancy;
- Cannabis use during pregnancy;
- Antidepressant use during pregnancy;
- Polycystic ovary syndrome;
- Infant opioid withdrawal;
- Zinc deficiency;
- Sulfate deficiency;
- Processed foods;
- Maternal occupational exposure to solvents;
- Congenital heart disease;
- Insufficient placental allopregnanolone.
- Estrogen in the womb;
- Morning sickness;
- Paternal family history;
- Parental preterm birth;
- Antiseizure meds
- Location of forebears
- Lithium
- Aspartame
- BPA
- Brain inflammation
- Maternal asthma
- Infertility
- Ultraprocessed foods
- Household chemicals
