What are the factors that complicate a diagnosis of anxiety versus an adjustment disorder?

No complication: An adjustment d/o can take shape of an anxiety d/o, . Under the umbrella of anxiety d/o's falls panic d/o, generalized anxiety d/o, social anxiety d/o, ocd, ptsd, phobias such as of heights , tunnels, or blood, adjustment disorder with anxious mood, anxiety resulting from abuse , and /or withdrawal from alcohol and drugs , and anxiety resulting from physical conditions such as hyperthyroidism.

General vs specific: One way to think of this is in adjustment disorder a person acts out dysfunctionally due to a stressor and is generally short-term (resolves within 6 months). It may include anxiety or other mood symptoms; however, it is kind of a "catch all" for maladaptive responses to a specific stimulus that do not otherwise meet the criteria for another mental health disorder, such as an anxiety disorder.