Attention-deficit hyperactivity disorder (ADHD) is highly comorbid with other psychiatric disorders. Each of the comorbid disorders modifies the overall clinical presentation and treatment response. Sometimes there can be more complex situations. For example, depressed children demonstrate diminished concentration and irritability and it may be difficult to differentiate from the cardinal symptoms of ADHD. Children with ADHD and comorbid disorders have poorer prognoses than those with ADHD alone.
Both stimulant medications and atomoxetine markedly reduce symptoms of comorbid oppositional defiant disorder, which often requires adjunctive parent training and behavior management. Severely explosive anger may require the use of atypical antipsychotics. In conduct disorder, stimulant medications and atomoxetine also reduce aggressive behavior and antisocial acts. Atypical psychotics or mood stabilizers may be used for highly aggressive-explosive cases.
The majority of children with comorbid ADHD/depression can be managed with a psycho stimulant. However, initial treatment with antidepressant drugs should be saved for treating children with more severe depression. Stimulants can exacerbate symptoms of anxiety disorders. Atomoxetine, SSRIs and behavioral therapies reduce anxiety symptoms.
If tic disorders are mild or episodic, they usually require no treatment. Most ADHD/tic disorder patients will not demonstrate an exacerbation of their tics with stimulants. Nevertheless, if tics worsen with stimulant use, an antipsychotic or alpha agonist should be added to the psychostimulant.