Making the Diagnosis
Doctors may consider a diagnosis of cyclothymia if there is a history of mood instability for a period of at least two years, and symptom-free intervals never last more than two months. For children and adolescents, symptoms only need to be present for a one-year period.
Cyclothymia will otherwise be difficult to diagnose if a person's mood instability has not been recognized and tracked over at least a couple of years. Because mood may be normal and stable for long periods of time - and mood elevations or depressions can be quite mild - symptoms do not always attract medical attention. People may not look for help until symptoms and mood swings become severe enough to interrupt normal functioning and activities.
If a person has experienced major depressive, manic, or mixed episodes, the diagnosis will likely be changed to bipolar I or II disorder. Your doctor will usually also need to rule out other conditions as these symptoms could be caused by substance abuse, physiological effects of certain medications, or an unrelated medical condition.