It is now know that about half of all people with ADHD also have a secondary or co-morbid condition. (https://www.additudemag.com/when-its-not-just-adhd/)

Studies show that people with ADHD have an increased risk of also suffering from other psychological problems: particularly depression, anxiety and substance abuse. This is often because their ADHD went undiagnosed and untreated in childhood and this can then have a secondary effect on mood, developing self-esteem, anxiety or worry. Some adults develop coping strategies that mediate against or lessen some of the symptoms, but these may often become maladaptive or harmful in other ways. At the ADHD Centre our psychiatrists are all trained in general psychiatry