If after five years of treatment for depression my lack of concentration persists over and over again. could it be adhd?

YES IT COULD BE: Plenty of good treatments, but you need seen.

Anything is possible: Having one problem doesn't mean you can't have another. Why not talk with your doctor about that possibility?

Concentration: Lack of concentration or inattention is only one symptom of adhd. Others can be disorganization, not finishing tasks, forgetfulness, misplacing things, overwhelmed with tasks, etc. Your doctor can reassess & give advice.

Could be processing : Lack of focus can be from learning or processing problems. Medications will not fix those.

Lack of concentratio: Further evaluation to confirm/rule out the cause can warrant further interventions.

Yes,no,maybe: Hyou could have co-existing adhd, however unresolved depression is more likely the ptoblem.Are you seen a therapist, taking meds, exercising, etc.Please see your doctor, talk to your therapist...It might be time for a re-evaluation.