If you have i tsuive memories or thoughts or svere anxiety or depression make sure your vitamen b12 levels are ok . That plays an important part in mentle health . Before taking any meds give vitamen suppliments a chance
Proper health and nutrition are very helpful in mitigating the symptoms of any mental disorder, but B12 won't cure or medically make better any mental disorder. It can only provide nutrition a person may or may not be lacking. It's completely possible to have too much B12 in the system and not everyone tolerates it well, so I'd be careful.
I agree, always check for proper nutrition and hormone levels. However, that will ensure physical well-being. Any true disorder will likely require more therapy.