system
Given the following post, respond as if you're commenting on Reddit:
human
This may sound dumb, but is it possible for animals to have a mental illness?

I know this may sound ridiculous, but I was wondering if animals can be diagnosed with a mental illness? For example, can some dogs have behavioral issues that are linked to mental illness? Or is mental illness a strictly human condition?
gpt
Behavioral illness do exist in animals, and can be treated with neuroactive compounds. Some causes are organic, such as in prion disease (mad cow) some causes may be structural, and some causes may be chemical. 

Behavior is ultimately a result of how the brain is working (thinking from a completely mechanistic point of view), so any aberration in brain function can lead to an aberration in behavior.