* Trauma and Abuse: Erik's history includes significant trauma. He is shown to be physically abusive towards others, particularly Paul Fisher, and to have violent outbursts. This points to a possibility of past abuse, possibly at the hands of his father, which could be a significant factor in his mental state.
* Lack of Parental Support: Erik lacks a strong parental figure in his life. His father is absent and emotionally distant, while his mother seems to be struggling with her own personal issues, leaving him with limited support and guidance. This lack of support could further contribute to his emotional and behavioral problems.
* Family History: The novel hints at a history of mental illness in Erik's family. This could indicate a genetic predisposition that makes him more vulnerable to developing similar issues.
* Internalized Rage and Frustration: Erik's behavior often seems driven by a deep-seated anger and frustration. This anger might stem from his feeling powerless, unseen, and unheard. He feels resentment towards his brother Paul, who is praised and favored by their parents. This internalized rage could contribute to his destructive and violent actions.
It's important to remember that "Tangerine" is a fictional narrative. The novel focuses on the impact of Erik's behavior and the psychological toll it takes on those around him. The novel doesn't aim to offer a definitive diagnosis or explanation for Erik's condition.
Ultimately, Erik's mental illness is presented as a complex and multifaceted issue, likely influenced by a combination of factors, rather than a single, easily identifiable cause.