No. "State of mind" could just mean that he is sad, happy, worried, concerned, anxious, ecstatic etc. His "mental state" suggests something far more clinical, such as schizophrenic, bi-polar, depressed, manic.
No. "State of mind" could just mean that he is sad, happy, worried, concerned, anxious, ecstatic etc. His "mental state" suggests something far more clinical, such as schizophrenic, bi-polar, depressed, manic.
That's true of usage in a medical context. They mean the same thing though, and in some contexts they could both be used. "Police investigators are trying to work out the suspect's mental state/state of mind at the time of the crime." This covers both 'normal' and pathological mental states.