For most jobs, the employer is not legally allowed to ask whether you have any medical diagnosis, psychiatric or not. Instead, they are allowed to ask whether you have any medical diagnoses that you believe will hamper your ability to perform your job duties to maximal success. In other words, you are not required to disclose any such information unless you want to.

There are a set of other jobs that will involve a psychiatric examination, such as police. I'm not sure if these would also want clearance to your medical records or if they would just perform their own evaluation. For jobs where this doesn't apply, I'm inclined to side with Stoda in that people may blame their medical conditions as the primary cause for not landing the job.