ADHD symptoms, chronotype, and vulnerability to postpartum depression: preliminary results from a two-stage prospective study

Background

Attention-deficit/hyperactivity disorder (ADHD) in women has emerged as a potential risk factor for postpartum depression (PPD), yet the underlying mechanisms remain poorly understood. Beyond its behavioral phenotype, ADHD is increasingly conceptualized as a condition associated with circadian rhythm alterations and sleep disturbances, including a tendency toward evening chronotype [1]. These features may be particularly relevant during the perinatal period, a time characterized by significant biological, hormonal, and circadian changes. It has been suggested that such circadian and sleep-related characteristics may contribute to increased vulnerability to depressive symptoms in the postpartum period [2]. This study aimed to examine the association between prenatal ADHD symptoms and postpartum depressive symptoms, and to explore the potential roles of chronotype and sleep-related factors in this relationship.

Methods:

This ongoing two-stage prospective study included 88 pregnant women recruited from a perinatology outpatient clinic during the second or third trimester. In the first stage, participants were assessed using the Adult ADHD Self-Report Scale (ASRS), Wender Utah Rating Scale (WURS), Beck Depression Inventory (BDI), and a chronotype measure assessing morningness–eveningness preference.

In the second stage, participants were reassessed within 6 months postpartum using the Edinburgh Postnatal Depression Scale (EPDS), along with measures of daytime sleepiness and postpartum sleep quality. Statistical analyses included group comparisons, correlation analyses, multivariate regression, and mediation analyses using bootstrap resampling (5000 iterations). Subgroup analyses were conducted to further explore the role of chronotype within ADHD.

Results:

Postpartum depressive symptoms were present in 20.5% of participants, while 19.3% met criteria for probable ADHD. Prenatal ADHD symptoms were significantly associated with higher postpartum depressive symptoms across both ASRS and WURS measures (p ≤ .001).

Participants with ADHD symptoms showed significantly lower chronotype scores, indicating a tendency toward eveningness. Postpartum depressive symptoms were positively associated with ADHD symptoms, daytime sleepiness, and poorer postpartum sleep quality, and negatively associated with chronotype scores.

In multivariate regression analysis, postpartum sleep quality emerged as the only significant independent predictor of postpartum depressive symptoms (β = 0.30, p = .003), explaining 34.5% of the variance.

Mediation analyses indicated that postpartum sleep quality and daytime sleepiness partially mediated the association between ADHD symptoms and postpartum depression. Indirect effects were statistically significant, supporting the presence of partial mediation.

Subgroup analyses suggested that individuals with both ADHD symptoms and a tendency toward eveningness exhibited higher postpartum depressive symptoms compared to other chronotype groups.

Conclusions:

These findings suggest that ADHD symptoms during pregnancy are associated with increased vulnerability to postpartum depressive symptoms. Chronotype, particularly a tendency toward eveningness, and sleep disturbance may partly explain this association. The results support a model in which circadian and sleep-related factors contribute to the increased risk of postpartum depression in individuals with ADHD. Further research is needed to clarify causal pathways and to determine whether interventions targeting sleep and circadian regulation during the perinatal period may reduce this risk.

References

Coogan, A. N., & McGowan, N. M. (2017). A systematic review of circadian function, chronotype and chronotherapy in attention deficit hyperactivity disorder [review]. ADHD Attention Deficit and Hyperactivity Disorders, 07, 129–147. https://doi.org/10.1007/s12402-016-0214-5
Becker, S. P. (2020). ADHD and sleep: Recent advances and future directions. Current Opinion in Psychology, 34, 50–56. https://doi.org/10.1016/j.copsyc.2019.09.006