Pica in Childhood: Concurrent and Sequential Psychiatric Comorbidity

Pica is the persistent eating of nonnutritive, nonfood substances, and is associated with serious medical consequences. There has been a lack of research into the psychiatric comorbidities of pica, despite being important for informing clinical care. The current study examines psychiatric comorbidities of pica in childhood and the longitudinal relationship between childhood pica and adolescent eating disorders.

We analyzed data from the Avon Longitudinal Study of Parents and Children study. Pica and psychopathology, assessed with the Development and Well-Being Assessment and the Strengths and Difficulties Questionnaire, were assessed at about 7- and 10-years of age, and reported eating disorders (EDs) at 14-, 16-, and 18-years of age. We conducted linear and logistic regression models, adjusting for covariates, to identify concurrent psychiatric comorbidities, as well as risk for later EDs. We conducted the Benjamini-Hochberg correction procedure to correct for multiple testing.

Pica (prevalence ranged from 0.33% to 2.33% dependent on age) was associated with increased odds of any psychiatric disorder and behavioral disorders in early childhood (OR = 7.30, q < 0.001, and OR = 5.65, q < 0.001, respectively) and mid-childhood (OR = 5.75, q < 0.001, and OR = 10.66, q < 0.001, respectively), and greater concurrent hyperactivity, conduct problems, peer problems, prosocial difficulties, and emotional difficulties (q < 0.01 across analyses). We did not find evidence that pica presence increased odds for concurrent emotional disorders nor for later ED risk.

The association between pica and psychiatric and behavioral disorders indicates a likely shared etiology. Our findings provide insight into the psychiatric characteristics of children with pica and highlight they may require complex behavioral support beyond their eating difficulties.