Cyclothymic Disorder usually develops early in adult life leading to a chronic course of mood swings that vary from mild elation to mild depression. These mood swings, either elation or depression, can last for several months and become a stable mood then the mood can change.

Due to the mildness of the mood changes the person suffering from Cycloythmia will rarely bring it to medical attention. There are often changes in appetite, self-confidence, activity and sociability. Cycloythmic Disorder is most common in relatives of people who suffer from bipolar affective disorder, and some people who have cycloythmic disorder can develop bipolar affective disorder.

Cycloythmic Disorder may persist throughout adult life, either temporarily or permanently ceasing, or becoming more severe in mood swings, eventually leading to bipolar affective disorder or recurrent depressive disorder.