The occurrence of early childhood adversity is strongly linked to later self-harm, but there is poor understanding of how this distal risk factor might influence later behaviours. One possible mechanism is through an earlier onset of puberty in children exposed to adversity, since early puberty is associated with an increased risk of adolescent self-harm. We investigated whether early pubertal timing mediates the association between childhood adversity and later self-harm.

Participants were 6698 young people from a UK population-based birth cohort (ALSPAC). We measured exposure to nine types of adversity from 0 to 9 years old, and self-harm when participants were aged 16 and 21 years. Pubertal timing measures were age at peak height velocity (aPHV – males and females) and age at menarche (AAM). We used generalised structural equation modelling for analyses.

For every additional type of adversity; participants had an average 12–14% increased risk of self-harm by 16. Relative risk (RR) estimates were stronger for direct effects when outcomes were self-harm with suicidal intent. There was no evidence that earlier pubertal timing mediated the association between adversity and self-harm [indirect effect RR 1.00, 95% confidence interval (CI) 1.00–1.00 for aPHV and RR 1.00, 95% CI 1.00–1.01 for AAM].

A cumulative measure of exposure to multiple types of adversity does not confer an increased risk of self-harm via early pubertal timing, however both childhood adversity and early puberty are risk factors for later self-harm. Research identifying mechanisms underlying the link between childhood adversity and later self-harm is needed to inform interventions.

Early puberty is associated with an increased risk of self-harm in adolescent females but results for males are inconsistent. This may be due to the use of subjective measures of pubertal timing, which may be biased. There is also limited evidence for the persistence of pubertal timing effects beyond adolescence, particularly in males. The primary aim of the current study was therefore to examine the association between pubertal timing and self-harm in both sexes during adolescence and young adulthood, using an objective measure of pubertal timing (age at peak height velocity; aPHV). A secondary aim was to examine whether this association differs for self-harm with v. without suicidal intent.

The sample (n = 5369, 47% male) was drawn from the Avon Longitudinal Study of Parents and Children (ALSPAC), a prospective birth cohort study. Mixed-effects growth curve models were used to calculate aPHV. Lifetime history of self-harm was self-reported at age 16 and 21 years, and associated suicidal intent was examined at age 16 years. Associations were estimated using multivariable logistic regression adjusted for a range of confounders. Missing data were imputed using Multiple Imputation by Chained Equations.

Later aPHV was associated with a reduced risk of self-harm at 16 years in both sexes (females: adjusted per-year increase in aPHV OR 0.85; 95% CI 0.75–0.96; males: OR 0.72; 95% CI 0.59–0.88). Associations were similar for self-harm with and without suicidal intent. There was some evidence of an association by age 21 years in females (adjusted per-year increase in aPHV OR 0.91; 95% CI 0.80–1.04), although the findings did not reach conventional levels of significance. There was no evidence of an association by age 21 years in males (adjusted per-year increase in aPHV OR 0.99; 95% CI 0.74–1.31).

Earlier developing adolescents represent a group at increased risk of self-harm. This increased risk attenuates as adolescents transition into adulthood, particularly in males. Future research is needed to identify the modifiable mechanisms underlying the association between pubertal timing and self-harm risk in order to develop interventions to reduce self-harm in adolescence.

Previous studies of pubertal timing and self-harm are limited by subjective measures of pubertal timing or by the conflation of self-harm with suicide attempts and ideation. The current study investigates the association between an objective measure of pubertal timing – age at menarche – and self-harm with and without suicidal intent in adolescence and adulthood in females.

Birth cohort study based on 4042 females from the Avon Longitudinal Study of Parents and Children (ALSPAC). Age at menarche was assessed prospectively between ages 8 and 17 years. Lifetime history of self-harm was self-reported at ages 16 and 21 years. Associations between age at menarche and self-harm, both with and without suicidal intent, were examined using multivariable logistic regression.

Later age at menarche was associated with a lower risk of lifetime self-harm at age 16 years (OR per-year increase in age at menarche 0.87; 95% CI 0.80–0.95). Compared with normative timing, early menarche (<11.5 years) was associated with an increased risk of self-harm (OR 1.31, 95% CI 1.04–1.64) and later menarche (>13.8 years) with a reduced risk (OR 0.74, 95% CI 0.58–0.93). The pattern of association was similar at age 21 years (OR per-year increase in age at menarche 0.92, 95% CI 0.85–1.00). There was no strong evidence for a difference in associations with suicidal v. non-suicidal self-harm.

Risk of self-harm is higher in females with early menarche onset. Future research is needed to establish whether this association is causal and to identify potential mechanisms.