What does the DC Comics film “Joker” have to do with early childhood mental health? In a word: everything.

“Joker,” the highest-grossing R-rated film in history, masterfully chronicles the devolving trajectory of the infamous villain in the “Batman” series. The movie injects elements of humanity and social commentary as it relates to mental illness. As an early childhood mental health advocate at the Erikson Institute, a Chicago graduate school and policy hub focused on young children, I was reminded of the enduring impact of early childhood experiences. The importance of relationships and the critical impact clinical programs and services make were apparent throughout the film.

Young children experience the world through relationships, and Joker did not receive the love and support we all need. He experienced physical abuse and neglect by his stepfather. He was adopted by a woman who was living with her own mental illness, which prevented her from being the nurturing force he needed. These relationships could have made him feel safe and protected and buffered his trauma, but instead were limited and empty.

Toxic stress had a profound impact on shaping Joker into a man all too quick to commit violent, unspeakable acts. When the brain’s and body’s stress response system is overactivated by danger and survival during childhood, the effect can be devastating.

Decades of brain science have proven that early and chronic exposure to trauma can literally get under our skin. Biological memories are formed that can harm the architecture of our brains. This is especially true in the first five years of life, when 90% of the brain is developed.

Trauma comes in many forms, but it often shows up as toxic stress through exposure to community violence. Analysis from Erikson’s Community Data Lab shows that in 2018, the majority of children under 5 in Chicago live in communities where 90% of the city’s homicides occur. Yes, trauma and stress are felt and experienced by children even if they do not directly witness a violent incident in their midst.

The film also provides a nuanced analysis of the role of clinical supports provided by public entities. In one exchange between Joker and his social worker, she explains that because of budget cuts, her services and his access to medicine would end. His pleas for help are met with her own frustrations in the broken system.

From that point forward, his fragile world begins to further unravel. He is unable to maintain his job, which has an impact on his ability to care for his mother. This increases his need to manage stress, yet the previous resources he relied on were no longer available. Unfortunately, this is not just a fictitious scenario that happens to movie villains. Restricted access to public mental health services is happening too frequently.

We have a duty to craft and implement plans that put the well-being of young children at the forefront. Our task is to call for funds to support the mental health needs of children starting from birth. The science provides evidence of the benefits and effectiveness of intervening early, an idea that draws bipartisan support.

As millions of moviegoers watch “The Joker,” they see how all too often we are willing to tolerate systems and services that fail to address the mental health needs of children — and how they and others ultimately suffer the consequences.

Cristina Pacione-Zayas is associate vice president of policy at the Erikson Institute of Chicago. This piece originally ran in the Chicago Tribune.