Very often, and especially as one gets older, other conditions can exist along with ADHD, requiring additional treatment. Some conditions that may coexist with ADHD are:

• Mood disorders: Includes depression and bipolar disorders. Both disorders feature "down" and sad moods with a lack of interest in daily activities, while bipolar disorder also includes extreme sharp swings "up" in mood and an inappropriate lack of inhibition.
  
  
• Substance abuse: Though a frequent occurrence among people with mood disorders and ADHD, studies have shown that receiving treatment for mood disorders and ADHD, if caught early enough, can help prevent substance abuse.
  
  
• Anxiety disorders: Includes phobias, obsessive compulsive disorder, panic disorders, and generalized anxiety, these disorders often feature excessive fear and/or worry.
  
  
• Behavioral and learning disorders: Includes Conduct Disorder (CD), Oppositional Defiant Disorder (ODD), and dyslexia. Associated features include low self-esteem and poor social skills.