Investigating the childhood origins of mental disorders and genetics

Background

Mental disorders are common, and contribute more to the global burden of disease than any other type of disorder. Most mental disorders, even ones that start in adult life, are thought to have their origins at least in part in childhood, although the characteristics in childhood may not be the same as the adult disorder.

As part of the child and adolescent psychiatry team, this research aimed to identify childhood mental health and neurodevelopmental traits in the general population that are associated with the genetic risk for “adult” mental disorders including depression, bipolar disorder and schizophrenia.

Research approach

We calculated genetic risk scores for mental disorders in two large community samples. Risk scores are calculated based on previously identified associations between common genetic variants (single-nucleotide polymorphisms; SNPs) and schizophrenia, bipolar disorder, major depressive disorder and attention-deficit hyperactivity disorder (ADHD).

We investigated the impact of these genetic risk scores on specific domains measured in childhood and found associations between genetic risk scores for schizophrenia and childhood cognitive, social, behavioural, and emotional (anxiety and mood) impairments.

We also investigated longitudinal trajectories of anxiety and depression (emotional problems). We found that while schizophrenia genetic risk scores were associated with emotional problems from childhood to adulthood, genetic risk scores for major depressive disorder were associated with emotional problems only later in adulthood.

Finally, we investigated the contribution of environmental risk (bullying) to changes in emotional problems (anxiety and depression) over time. We found that while schizophrenia genetic risk scores were associated with early-onset emotional problems, being bullied in childhood contributed to those shifting from an initially low level of emotional problems to an elevated trajectory through adolescence.

Outcome

Our work aims to enhance understanding about the early origins and later trajectories of mental disorders. This could inform programmes that aim to prevent and target mental disorders as early as possible.

Other researchers working on this project include: