Investigating overlooked eating disorders in childhood

Published in the International Journal of Eating Disorders, Dr Sam Chawner’s recent study explores the relationship between pica and other psychiatric conditions in childhood. The findings reveal that children with pica may benefit from screening for neurodevelopmental and mental health conditions.

What is pica?

Pica is a feeding disorder in which someone eats non-food substances that lack nutritional value – such as paper, soap, paint or chalk. It is diagnosed if the behaviour persists for at least one month, is not part of a cultural practice, and is developmentally inappropriate – generally, children under the age of two are not diagnosed with pica as its common for babies to ‘mouth’ objects.

According to Beat, the UK’s eating disorder charity, pica is often not revealed until medical consequences occur, for example, metal toxicity, cracked teeth, or infections.

What have previous pica studies taught us?

Some studies have reported that pica is more common in autistic children than children without autism, although it is certainly not exclusive to this group.

However, to date, there has been a lack of research investigating the link between pica and other neurodevelopmental and mental health conditions. For instance, pica has been considered as a potential compulsive behaviour, but no study has examined its prevalence among children with OCD. Similarly, the relationship between pica and anxiety or depression in children remains unclear, and evidence regarding its association with other eating disorders has been mixed.

Recognising this gap in knowledge, Dr Chawner and his colleagues have explored the overlap between pica and other psychiatric conditions in this study. Dr Chawner adds:

"Thanks to the generous funding of a Medical Research Foundation Eating Disorders Fellowship, I have been able to conduct research into eating disorders which have been historically under-researched included Pica and Avoidant Restrictive Food Intake Disorder (ARFID).”

Investigating pica in childhood

The team used data from approximately 10,000 children from the Avon Longitudinal Study of Parents and Children.

The researchers found that, in childhood, pica was associated with an increased likelihood of having a behavioural disorder (such as ADHD and conduct disorder), but not emotional disorders (such as OCD, anxiety and depression).

Dr Chawner also found that childhood pica was not linked with a greater chance of developing another eating disorder, like anorexia nervosa, during adolescence.

Commenting on the results, Dr Chawner says:

“Our findings suggest an association and a potential shared cause between pica and psychiatric behavioural disorders. This may indicate potential shared mechanisms and treatment approaches.”

The study highlights the complex needs of children living with pica, who may experience challenges in their peer relationships, in addition to emotional and behavioural health. Findings show that, on the whole, children with pica may struggle more with behavioural disorders.

There is also evidence to suggest that feeding disorders could overlap with each other more than feeding and eating disorders. In other words, while pica in childhood does not appear to be connected to an increased risk of developing another eating disorder in adolescence, there could be overlap between pica and feeding disorders like ARFID (avoidant/restrictive food intake disorder). However, future work is needed to ascertain this, looking at the long-term relationships between ARFID and pica across a child’s development.

Importantly, the findings emphasise that children with pica may require multifaceted behavioural support that goes beyond their eating difficulties - such as behavioural therapies that promote self-soothing behaviours. Dr Chawner’s initial work in this area provides a foundation for future studies that could shed more light on the overlap between pica and neurodevelopmental and mental health conditions.

Read the full paper 'Pica in Childhood: Concurrent and Sequential Psychiatric Comorbidity' here in the International Journal of Eating Disorders.