Which theory dominated the understanding of mental illness in Europe after the fall of the Roman Empire?

The correct answer is demonology, as this theory played a significant role in shaping the understanding of mental illness in Europe after the fall of the Roman Empire. During this period, mental illnesses were often attributed to supernatural forces, such as demonic possession or witchcraft. This perspective led to various methods of treatment, which included exorcism, prayers, and other religious rituals, reflecting the belief that mental health issues were caused by evil spirits.

Demonology's influence stemmed from the prevailing cultural and religious beliefs of the time, where the medical understanding of mental health was rudimentary at best. This focus on the mystical and supernatural persisted for centuries, overshadowing other approaches until more scientific understandings of mental illness began to emerge in later periods.

The other options, such as psychodynamic theory, humanism, and behaviorism, gained prominence in the 19th and 20th centuries, long after the fall of the Roman Empire. Psychodynamic theory, for example, developed from the work of Sigmund Freud, focusing on unconscious processes and childhood experiences. Humanism emphasized personal growth and self-actualization, while behaviorism concentrated on observable behaviors and environmental factors. None of these theories were predominant during the early medieval period when demonological explanations prevailed