Final answer:
Infections can be a biological factor involved in the development of mental illness.
Step-by-step explanation:
One biological factor that may be involved in the development of mental illness is infections. Infections can lead to inflammation in the brain, which can disrupt normal brain functioning and potentially contribute to the development of mental disorders.
It is important to note that mental illness is a complex condition and is influenced by various factors, including genetic, environmental, and psychological factors. Therefore, it is not solely caused by infections, but they can be a contributing factor.
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