I have a friend that used to work with me few years ago. We are not so good friends lately, and I do not see him commonly. Anyway, last time I saw him, he seemed so strange like that is not the same person as he used to be. He was acting strange and was some kind depressed. I have noticed yellowing of him eyes, so I wonder if that could be caused by some mental condition.
I cannot give you diagnosis of your friend online without any further info about his condition. I cannot tell you if he has some mental problems or not, just like this. However, I can say if he seemed as depressed, he might have several mental disorders, some are light and some severe. I cannot tell you exactly, but this might be typical depression, or even bipolar disorder. This diagnosis might be confirmed with yellowing of the eyes. I am saying that because yellowing of the eyes is side effect of the most medicines that are used to treat mental conditions. Olanzapine, for example, is used to treat mental condition such as schizophrenia, and bipolar mania. Problem with this drug is that causes a lot side effects, such as dizziness, stomach pain, constipation, dry mouth and yellowing of the eyes. The last one is unlikely but serious side effect, and he should immediately tell this to his doctor.