A personality pattern disturbance characterized by frequently alternating moods of elation and dejection.The cyclothymic (or cycloid) individual tends to be extraversive, responsive, and socially dependent. It is sometimes possible to trace his changes of mood to acceptance or rejection by other people; but more often these fluctuations appear to occur spontaneously and cannot be related to outside events. They are apparently associated with feelings and attitudes which are deeply embedded in the individual’s emotional life. The cyclothyme’s mood changes are likely to be frequent and rapid. At one time he is cheerful, vivacious, and euphoric, but he soon swings unaccountably to a state of sadness or mild depression. The tempo of his entire behavior changes with his mood, and he is therefore lively and active during one period and slow and ponderous during the other. The pendulum, however, rarely swings all the way, for the cyclothymic personality does not usually reach the pathological extremes of exaltation with hyperactivity on the one hand, and despair with psychomotor retardation on the other. In other words, in spite of the fact that the cyclothymic individual’s moods are frequently exaggerated, he is still an integrated personality and can meet the demands of life more or less effectively. However, if he is subjected to extreme and prolonged stress, his personality may become disorg anized, and he may develop a manic-depressive psychosis.Some cyclothymes persist in one phase of the cycle and develop the characteristic personality pattern of that phase to an especially high degree. The euphoric type is termed hypomanic personality; the depressed type is the melancholic personality. See these topics. Illustrative Case: CYCLOTHYMIC PERSONALITY This patient, a businessman of forty- three, sought psychiatric help while during a depressed phase in which he felt his entire life was a miserable failure. As the history developed it became clear that all of his friends recognized him as being an extremely changeable individual who was apt to be either elated or depressed for periods of several weeks at a time. When “feeling good,” as he put it, he preferred to play cards, entertain extensively, seek out all possible outside social contacts, and spend a great deal of energy on his business. Such a phase, however, would come to an end for no reason of which he was aware. He would then spend a few weeks in which his mood change was remarkable. He found going to work a drudgery. He felt that his thriving business could not possibly continue to be a success, he condemned himself for some of the business deals that he had made, and felt that his product was inferior and could not be made into anything acceptable. He gave up his social activities, snubbed his friends, and was generally irritable and cantankerous with his own family. It was difficult to draw him into a conversation and he seemed to be distant, withdrawn, and uninterested in social contacts. Therapy with this patient primarily involved attempts to give him an understanding of some of the mechanisms which precipitated his wide mood changes. He had a rather severe superego from which he periodically escaped into an elated phase and which then caught up with him and again forced him into a self-depreciatory phase. As he gradually learned some of the unrealistic aspects of his rigid conscience, he began to blame himself less punitively for his activities. As a result it was possible for him to feel some renewed interest in his business, his friends, and his family. At the same time this made it unnecessary for him to “run” into his elated phase in order to escape his severe conscience. This patient essentially had many of the dynamics of a compulsive patient and his therapy was somewhat similar, although he presented no overt neurotic symptoms but instead a personality problem primarily illustrated by his remarkable mood swings. (English and Finch, 1964) CYTOMEGALIC INCLUSION BODY DISEASE. A mild virus infection in the mother which may cause brain damage in the fetus, together with enlargement of the liver and the spleen (hep- atosplenomegaly), jaundice, and erythroblastosis (yellow baby disease). The disorder is recognized by the presence of inclusion bodies in the urine, cerebrospinal fluid, and other tissues. It is one of the rarer causes of severe mental retardation. See MENTAL RETARDATION (CAUSES).