How chronic diseases can affect personality?

Multiple Sclerosis (MS)

With this condition, your immune system attacks the nerves in your brain and spine. It can cause problems ranging from bladder issues to not being able to walk. In some cases, it can lead to a feeling of euphoria, where your happiness is beyond normal and out of touch with reality. It can also bring on laughing or crying that seems out of control or not in line with how you really feel.