Cyclothymia is a primary mood disorder that is, by definition, characterized by episodes that do not meet the criteria for hypomania or major depression. It is currently classified under the umbrella of bipolar mood disorders. It is a chronic disease that must be present for at least two years in order to be diagnosable in adults and over 1 year in children and adolescents. As with many other psychiatric disorders, it must lead to dysfunction and stress in order to be classified as a disorder and must not be concurrent or caused by another general medical condition or substance use disorder. Despite this, it often coincides with substance abuse, and the recurrent mood swings often are detrimental to the patient's personal and professional life. In this article, shedding light on this under-diagnosed disease will be the main objective.
The etiology of bipolar type mood disorders combines a wide array of risk factors that include genetic susceptibility, neurotransmitter dysregulation, environmental triggers, and possibly drug triggers as well. Cyclothymia is thought to belong to this family of mood disorders and is treated as such. The bipolar family of disorders has numerous triggers and explanation with the most implicated factors is being enumerated here.
Genetic susceptibility is a current area of research with a wide variety of loci being investigated, including 18p11, 13q32, CLOCK genes, and ANK3, along with a widespread field across the genetic profile of patients. There is much overlap with other psychiatric mood and thought disorders, including schizophrenia and schizoaffective disorders. Demonstrative of the importance of genetics in this disease, the concordance rates among identical twins average 57%.
Neurotransmitter dysregulation is important to this family of mood disorders. Despite being a common-sense idea, the absolute level of neurotransmitter is not directly tied to episodes of mania or depression. Dopamine is commonly implicated with bipolar type disorders as several drugs, and increased dopaminergic activity are more sensitive in patients with bipolar type disorders. The dopaminergic increase may lead to talkativeness, elevated mood, and energy in bipolar disorder spectrum patients. Low levels of serotonin are commonly implicated in mood disorders, and depletion of serotonin produces more cognitive deficits in patients with bipolar disorders.
Neurobiology and genetic factors play a large role but do not adequately explain the heterogeneity of bipolar disorders. Environmental factors play a large role in the development of bipolar disorders. Negative life events and negative cognitive styles are associated with an increased incidence of acute depressive episodes in the bipolar family. Acute mania may be linked to goal dysregulation stemming from increased sensitivity in the dopaminergic pathway. Numerous studies have implicated stressful events to be a trigger in 20 to 66% in one to three months before the onset of a mood episode.
This family of disorders is prevalent around the world. Often it is equated only with bipolar I disorder, which is the most severe manifestation of this group. The lifetime prevalence of bipolar I disorder is approximately 1%. After including bipolar II disorder in addition to cyclothymia and rapid cycling, the prevalence jumps to around 5% for bipolar disorder. The gender ratio is believed to be 1:1, but the strong social factors affecting males to deny emotionally negative events result in the condition being under-reported in current research. The mean age for symptom onset is approximately 18 years old for bipolar I. Bipolar II disorder, and related disorders have a mean age of symptom onset of 22 years old.
An interesting aspect of this disease is that manic and depressive symptoms have been commented on as far back as antiquity. Aristotle's lecture "on melancholy" can be interpreted as talking about manic symptoms and the genius produced from this. It speaks to the deep-seated cultural mores surrounding cyclothymia and other mood disorders and may represent a barrier to studying them.
The pathophysiology of bipolar disorder is not well understood but is believed to be a combination of environmental factors and changes in neurotransmitter regulation and transmission. Environmental factors include stressful life events with particular events, including the suicide of a family member, sleep cycle disruptions, family members with high emotional expression, and family dynamics that are hostile and critical. Neurotransmitters implicated are serotonin, dopamine, and epinephrine, with dopamine being implicated in the manic symptoms characteristic of these disorders.
The most common presenting state in patients with bipolar/cyclothymia is in the depressed or mixed state. A mixed state would include a depressed mood with increased energy, restlessness, or racing thoughts. The clinician should rule out the history of manic episodes in all depressed patients with clues in the history, including reduced need for sleep, racing thoughts that prevent sleep, persistent irritability, and severe mood swings. Other clues to the diagnosis include episodes of excessive gambling, reckless sexual activity, family history of bipolar disorder, impulsivity, multiple divorces, legal or financial problems, history of attempted suicide, and recurrent job loss.
Physical findings in a manic episode include a restless or anxious patient, one who cannot sit still, excessive and expansive mood, or reckless/risky sexual behaviors.
Physical findings in the depressed patient include a constricted affect, psychomotor depression, decreased mood, and suicidal thoughts.
In cyclothymia, any of these are possible as, by definition, these patients do not specifically meet all criteria for a manic, hypomanic, or depressive episode.
For reference to criteria for manic, hypomanic, or major depressive episodes, please see the DSM-V or the article related to bipolar affective disorders.
The evaluation of this family of disorders includes doing basic lab work to rule out general medical conditions (depending upon the symptomatology, especially if any psychosis is present) including a complete blood count, comprehensive metabolic profile, a thyroid-stimulating hormone test with T3 and T4, B12, folate, niacin, and urine/serum drug screen. A substance abuse history should be noted. All patients should be screened using the beck depression inventory to objectively delineate depression. Infectious diseases should be screened for, including Lyme disease and syphilis. Medications should be screened for possibly precipitating mood changes, including neurologic and psychiatric medications specifically. Specific mood disorder questionnaires with sensitivity for bipolar family disorders include the Bipolar spectrum diagnostic scale and the My Mood Monitor (M-3) checklist.
As noted above, cyclothymic patients will not meet the criteria for a manic, hypomanic, or depressive episode. They cannot have a history of any of these episodes during the point of their illness, and symptoms must be present for at least 2 years. The hypomanic and depressive symptoms are of an inadequate number, duration, and severity required for a hypomanic/manic or a major depressive episode.
The treatment of cyclothymia and the bipolar family of disorders rests upon managing risk factors, recognizing early symptoms, and utilizing treatment, including counseling and pharmacologic interventions. For cyclothymia, psychoeducation and delineation of their disorder are paramount. The patient is a powerful ally in treating this disease. The cornerstone of the treatment of cyclothymia is the addition of a mood stabilizer. Small doses are better utilized in cyclothymic patients. Valproate is recommended if anxiety is dominant. Lamotrigine is recommended if the anxious-depressive polarity is more prominent. Lithium is recommended if the affective intensity is present.
Treatment should be defined in terms of stages with the acute period being 0 to 8 weeks with symptomatology present. Psychoeducation should be instituted with low dose mood stabilizers with adjunctive treatment initiated if needed (such as antidepressants). The continuation phase should follow and is a period of 1 to 6 months after functional recovery with reinforcement of psychoeducation with cognitive reorganization and emotional coaching focused on counseling. The maintenance phase follows with the continuation of low dose mood stabilizers and monitoring for the return of symptoms.
There are many mimics of mood disorders, and they include drugs of abuse (alcohol, amphetamines, cocaine and hallucinogens, opiates), medications (levodopa, steroids and many psychiatric agents including antidepressants), syphilis, endocrine diseases, systemic lupus erythematosus, vitamin deficiencies (such as folate or B12) and other mood disorders.
Prognosis of cyclothymia is generally good if the patient is able to seek treatment. Roughly 1/3rd of patients develop a mood disorder, most commonly bipolar II disorder. Prognosis varies by internal coping styles, personality factors, family support, and early initiation of medications and psychotherapy. Though if left untreated manic episodes can continue for up to 6 months if the patient progresses into criteria-meeting for other bipolar disorders. There is some thought that cyclothymia is a "precursor" to other bipolar disorders.
There is some notion of a "kindling" effect with a cyclothymic disorder that may run concurrently with other psychiatric disorders. Cyclothymia and cyclothymic like symptoms may be a predisposition to reacting strongly to both internal and external stimuli with large central nervous system responses. This has been associated in some studies to lead to poorer outcomes.
The most serious consequence of the family of bipolar disorders is suicide. In addition to this, there is extreme morbidity possible due to the underlying symptoms of cyclothymia, which encompass any of the possible consequences of bipolar disorder, including frequent and unstable relationships, inability to function in society, and severe psychosocial distress.
As stated previously, there is a great amount to be gained in psychoeducation with the patient and helping them to understand their own disorder. The fact that it is frequently misdiagnosed due to not meeting criteria for other, more clear-cut, and more established disorders contributes to the significant morbidity of this disease. A special focus should be directed at teaching the patient that the problem lies in affective instability.
Management of cyclothymia and the rest of the family of bipolar disorders often require an interprofessional team approach, including the primary care clinician, a psychiatrist, a psychologist or social worker, and the support team that the patient has around them in terms of family and friends. Often this goes undiagnosed or misdiagnosed, which contributes to morbidity and mortality. Early consultation with psychiatry or inpatient hospitalization may be required if there are significant symptoms or if there is suicidality or progression to psychosis. [Level 4]
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