Parent and child mental health has suffered during the pandemic and transition phase. Structured and shared parenting may be intervention targets beneficial to families who are struggling with parent or child mental health challenges.

First, we investigated associations between structured and shared parenting and parent depression symptoms. Second, we investigated associations between structured and shared parenting and depression, hyperactivity/inattention and irritability symptoms in children.

A total of 1027 parents in two-parent households (4797 observations total; 85.1% mothers) completed online surveys about themselves and their children (aged 2–18 years) from April 2020 to July 2022. Structured parenting and shared parenting responsibilities were assessed from April 2020 to November 2021. Symptoms of parent depression, child depression, child hyperactivity and inattention, child irritability, and child emotional and conduct problems were assessed repeatedly (one to 14 times; median of four times) from April 2020 to July 2022.

Parents who reported higher levels of shared parenting responsibilities had lower depression symptoms (β = −0.09 to −0.32, all P < 0.01) longitudinally. Parents who reported higher levels of shared parenting responsibilities had children with fewer emotional problems (ages 2–5 years; β = −0.07, P < 0.05), fewer conduct problems (ages 2–5 years; β = −0.09, P < 0.01) and less irritability (ages 13–18 years; β = −0.27, P < 0.001) longitudinally. Structured parenting was associated with fewer conduct problems (ages 2–5 years; β = −0.05, P < 0.05).

Shared parenting is beneficial for parent and child mental health, even under chaotic or inflexible life conditions. Structured parenting is beneficial for younger children.