Stress related coughing does exist in my experience. It is an uncommon cause of chronic coughing. It is usually a cause of neck coughing (See "Neck Cough: The Coughing Nightmare"). The diagnosis is established by analyzing patterns of coughing throughout your life and making the correlation. Anxiety as a secondary factor certainly makes coughing worse in conditions such as public speaking, buisness meetings, disturbing your sleep or your partner's sleep to name a few. Please see Therapy for Stress Related Coughing.