It's hard to tell if this is ADHD or a symptom of depression.

ADHD does tend to run in tandem with depression or anxiety. I struggled with clinical depression and anxiety disorder for over half my life before being diagnosed in August with ADHD and started treatment. As I have been on medication for ADHD and working with an ADHD Coach, my depression and anxiety have gotten much better.

That said, with depression, increased distraction is part of the issue. Your best bet would be to see a mental health professional or doctor about being tested so you can get a clear diagnosis. It's hard, especially if you don't have a close relationship with the doctor, but it's very important to be as thorough and honest as possible. If you need to, write a list of symptoms, when they tend to get worse/better and bring it with you. I often have to create a list of what I want to go over with my pdoc before I see him. Otherwise I will be half way to work after the appointment and suddenly remember something I was going to bring up or ask...

Good luck!