Genetic effects primarily influence stability of hoarding symptoms.

Hoarding symptoms are stable during adolescence, mainly due to genetic effects, according to a study published in the open-access journal PLOS ONE by Volen Ivanov from the Karolinska Institutet, Sweden and colleagues.

People with Hoarding Disorder have extreme difficulty discarding their possessions, and sometimes may accumulate more possessions that they do not need, resulting in clutter around their living environment that impairs and distresses them. While the effects of Hoarding Disorder have mostly been studied in a clinical environment with adults, previous studies have suggested that hoarding symptoms may arise earlier in adolescence and young adulthood, although little is known about what causes these symptoms.

To investigate how genetic and environmental factors influence hoarding symptoms in adolescents and young adults, Ivanov and colleagues examined potential hoarding symptoms in three large cohorts of identical and fraternal twins aged 15, 18 and 20-28 with a questionnaire. Participants rated themselves on a scale for Hoarding Disorder indicators such as: clutter in their bedroom, difficulty discarding possessions, distress and impairment, and excessive acquisition of possessions. The researchers then analyzed the similarity of the scores of each pair of twins for identical twins and for fraternal twins to assess hoarding heritability.

Across all three cohorts, the authors found that hoarding symptoms were heritable and moderately stable between 15 - 18 years old and genetic effects could account for much of the stability in symptoms. They suggest that these findings could help inform treatments development in young people experiencing hoarding symptoms, preventing the potential progression into Hoarding Disorder as adults.

Article: Heritability of hoarding symptoms across adolescence and young adulthood: A longitudinal twin study, Ivanov VZ, Nordsletten A, Mataix-Cols D, Serlachius E, Lichtenstein P, Lundström S, et al., PLoS ONE, doi: 10.1371/journal.pone.0179541, published 28 June 2017.