I have noticed this, too. Everybody seems bipolar. Perhaps, I meet the criteria for the condition, around the time of the month. Sometimes, I wonder if the menstrual cycle contributes to the prevalence of bipolar, especially milder forms.

A lot of individuals with ASD also get diagnosed with bipolar, especially females. I know, I was told I had it at age 19. It made no sense to me and I did not believe it. Nothing about my behavior was bipolar. I was irritable because of sensory processing issues and medication.

Some of this is cultural.

In the past self harm was restricted to certain environments like group homes and institutions. Now, it has infiltrated mainstream society. A lot of teenagers do this because of peer pressure. Emo? Apparently, it is part of that culture. This problem is rife in adolescent psychiatric units.

My psychiatrist admitted many people learn how to self harm while in hospital.