With my nutritionist hat on, no person having a diagnosis of any health condition, mental health or otherwise, presents in the same way as another. Conditions are complex, and there is no one fit treatment for all. You are uniquely you, with your biochemistry and experiences.
Diagnoses are labels, while significant, they are words. You are experiencing symptoms which vary from person to person and the cause or trigger, if there is one, will be different too. These need to be taken into account regardless of the diagnoses.
On the other side of the coin, having received diagnoses such as CPTSD, OCD, and ADHD, I have found it to be incredibly helpful. To illustrate, I received my ADHD diagnosis as an adult. I put the pieces together myself after my energy drink addiction got out of hand. After much research, I realised that my addiction was a form of self-medication. Energy drinks provided me with a sense of calm and helped with agitation and focus.
A person with ADHD may be medicated with stimulants to help with these symptoms; this was what I was trying to replicate with the consumption of energy drinks. I was fortunate to have a fantastic GP who felt it was highly likely once I explained what was happening for me. I got referred appropriately to a psychiatrist who made the diagnoses.