So from what I understand there are officially two diagnostic categories for bipolar disorder which are defined quite specifically.

However while trying to understand whether or not I might have bipolar disorder I have talked to a few friends diagnosed with bipolar and a few friends who have questioned whether they might be bipolar.

From what my friends have said it often seems like it's really common not to really fit neatly into the diagnostic criteria. For example I have two friends with type two bipolar disorder who have experienced a full blown manic episode under unusual circumstances. One of them often has hypomanic episodes that only last one day. There are also edge cases where people have some bipolar traits but not enough to meet the diagnostic criteria.

I'm normally depressed but under unusual circumstances I've had a couple of 2-3 day long hypomanic episodes. It's possible that I've had more but I don't remember very well. I had psychosis (or something close to it) once years ago but no mania. I have some 'risk factors' including ADHD and a bipolar family member. It's not quite enough to get a diagnosis but I feel like it's close. Sort of like I have potential for hypomania to become a cyclic thing but it hasn't so far.

I was kind of stressing about whether or not I have bipolar disorder until I learned that it seems like it's actually pretty common to be kind of an 'edge case' with apparently [40% of Americans with major depression having had a manic or hypomanic episode](https://www.medicinenet.com/script/main/art.asp?articlekey=118977). There's also cyclothymia, [depressive episodes with short duration hypomania](https://www.theravive.com/therapedia/depressive-episodes-with-short--duration-hypomania-dsm--5), and apparently various other subtypes of bipolar.

It also seems like there may be hereditary connections between major depression, bipolar, and psychosis/schizophrenia?

I was reminded of the autistic spectrum (i.e. the range of different ways autism can manifest). Previously in the DSM autism had a few different subtypes such as Asperger's syndrome and PDD-NOS but under further study they were considered to be quite difficult to distinguish from one another and had so much overlap that they were collated into a single diagnosis of Autism Spectrum Disorder.

I'm wondering if the concept of "spectrum" could be similarly applied to bipolar disorder and its related conditions. What do you think?