It can be argued that animals experience some form of mental disorders similar to humans. To what degree and how similiar to humans is the debatable aspect. As animals cannot speak we cannot ask them how they feel or how they are affected so we have to determine this through their behaviour changes and physiological changes from the norm for that species. I suppose some scientists argue that as they are not as ‘developed’ as humans in their mental capacity then perhaps they do not experience these disorders in the same way. We do study mental disorders using animals as we do for physical ailments.