a computer virus could cause depression, which some call mentally ill, which can be paraphrased to 'sick in the head' [im not a fan of the term at all btw]
Havent read up on side effext of depression for a while, but oh, look!
Depression can affect the immune system, making it harder for your body to fight infection. Some vaccinations, such as the shingles vaccine, may even be less effective in older adults with depression. Depression has also been linked to heart disease and increased risk for substance abuse.
thats effed up!
I forgot all about that stuff till this thread brought it up. 
ps - just saw the post above me mentions anxiety, wonder how many virus were deployed simply to drive the victim nuts!
pps - some of the AI on my iPhone is so bad that at times I wonder if its been compromised.