What are some of the most common distractions a writer struggles with and how can one overcome them?

Maybe his mood swings and having his emotions controlling him, that will distract his thoughts and make it harder for him to concentrate or write.

1. Writer's block

2. External noise and/or internal issues bothering the writer

3. Feeling of indolence.  At times, writers just don't feel like writing at all.

One of the most effective remedy for this is to relax and loosen up, or change  environment.

Some of the distractions in writing can be: Not knowing exactly what to work on, Feeling restless, Thinking about looming deadlines for committee and service obligations, Doing things other than writing (but related to the project) for too long, e.g. reading too many articles, or spending too much time on them, communicating with co-authors instead of writing; It can be overcome by simply noticing your thoughts and to try not to argue with your gremlins. Instead, playfully experiment with ways to disempower your gremlins.