People that use their mental illness as an excuse for bad behavior.

There's a huge difference in an illness being the reason and it being the excuse.There are times my PTSD symptoms are in high gear and I say or do something I instantly regret. I apologize to my husband and explain to him why I reacted that way and make amends.He has done the same and has explained he was symptomatic and why.I don't say it's my PTSD all the time for every little thing,I only do when it really is.Neither does he.

That's way different than those that never make amends,never apologize,never explain and expect everyone to overlook everything they say and do.And if called out on their behavior they say something like "well you KNOW I have [insert illness here]" And they never work on changing their behavior,they never seek help,and they don't really care who they are upsetting or hurting by what they say or do.