What is classed as depression?

[sausage]

For doctors to give you anti-depressants in the UK........how depressed do you have to be.

I regularly feel negative about my hair, I am daily self conscious about it. I am generally a worrier and have been an anxious person all my life and was especially shy when I was at school but am a lot better these days but still a pretty anxious person. I daily think about all the girls I should have had sex with in the past. I am heading towards my 30's and am thinking I have not lived life to the full, my hairloss and anxiety being the main restricting factors.

I am in no way suicidal. But feel low a lot of the time. People I work with would not know this as I am pretty normal around others. I just have negative thoughts about how shit my life is on a daily basis.

Is this worthy of anti-depressants or do you have to be pretty mental to be prescribed them?