Bipolar disorder is a major mental health problem, characterized by acute episodes of clinically relevant sadness and mood swings, but whose expression may differ according to the diagnosed subtype.
The differences between the types are remarkable, and to determine precisely which one you suffer from, it is necessary to make an in-depth review of both the symptoms present and their history.
In addition, there is a third type: cyclotimia. In this specific case the symptoms are of lesser intensity for each of its poles, although it also generates a substantial impact on different areas of life.
In this article we will address the differences between bipolar disorder type I and II, in order to shed light on the issue and contribute to the accuracy of the diagnostic or treatment process, which are key to influence its clinical and prognostic outcome.
General Characteristics of Bipolar Disorder Subtypes
Before delving into the differences between bipolar disorder type I and II, it is important to know the main characteristics of each of the disorders that form the category . In general, these are problems that may debut in adolescence. In fact, in the event that depression occurs during this period, it can be understood as one of the risk factors for bipolarity in the future (although never in a decisive way).
Bipolar disorder type I has, as a distinctive element, a history of at least one manic episode in the past or present (mood swings, irritability and over-activity), and may alternate with stages of depression (sadness and difficulty experiencing pleasure). Both extremes are very severe and can even lead to psychotic symptoms (especially in the context of mania).
Type II bipolar disorder is characterized by the presence of at least one hypomanic phase (of lesser impact than manic but with similar expression) and one depressive phase, which are interspersed in no apparent order. For this diagnosis it is necessary that a manic episode has never been previously presented, otherwise it would be a subtype I. To make this nuance requires a very deep analysis of past experiences, because mania can go unnoticed.
Cyclothymia would be equivalent to dysthymia, but from the bipolar prism. In the same line, acute phases of mild depression and hypomania would concur, whose intensity and/or impact would not allow making the diagnosis of any of them separately (subclinical symptoms). The situation would continue for at least two years, generating disturbances in the quality of life and/or participation in significant activities.
Finally, there is an undifferentiated type, which would include people who have symptoms of bipolar disorder but do not meet any of the diagnoses described above.
Differences between bipolar disorder type I and II
Bipolar disorder type I and type II, along with cyclothymia and undifferentiated, are the conditions included in the category of bipolarity (formerly known as manic depression). Although they belong to the same family, there are important differences between them that must be taken into account, since a proper diagnosis is essential to provide a treatment adjusted to the care needs of each case.
In this article we will discuss the possible differences in variables related to the epidemiological , such as gender distribution and prevalence; as well as other clinical factors, such as depressive, manic and psychotic symptoms. Finally, the specific form of presentation (number of episodes) and the severity of each case will be discussed. Eventually, the particularity of cyclothymia will also be addressed.
1. Gender distribution
There is evidence to suggest that major depression, the most common of the problems that fall into the category of mood disorders, is more common in women than in men. The same is true for other psychopathologies, such as those included in the clinical spectrum of anxiety.
However, in the case of bipolar disorder, there are slight differences from this trend: the data suggest that men and women suffer from type I with the same frequency, but the same does not apply to type II.
In this case, women are the population most at risk, as is the case with cyclotimia. They are also more prone to mood changes associated with the time of year (seasonal sensitivity). Such findings are subject to discrepancies depending on the country in which the study is conducted.
Bipolar disorder type I is slightly more frequent than type II, with a prevalence of 0.6% compared to 0.4% , according to meta-analysis. It is therefore a relatively common health problem. In general (if both modalities are considered at the same time), it is estimated that up to 1% of the population may suffer from it, a fact similar to that observed in other mental health problems different from this one (such as schizophrenia).
3. Depressive symptoms
Depressive symptoms can occur in both type I and type II bipolar disorder, but there are important differences between the two that need to be considered . The first of these is that in type I bipolar disorder this symptom is not necessary for diagnosis, despite the fact that a very high percentage of people who suffer from it end up experiencing it at some point (over 90%). In principle, only one manic episode is needed to corroborate this disorder.
In bipolar disorder type II, however, its presence is mandatory. The person suffering from it must have experienced it at least once. In general, it tends to recur, interspersed with periods when the mood takes on a different sign: hypomania. In addition, it has been observed that depression in type II tends to be longer lasting than in type I, this being another of its differential features.
In the case of cyclothymia, the intensity of depressive symptoms never reaches the threshold of clinical relevance, contrary to what happens in bipolar disorders type I and II. In fact, this is one of the main differences between cyclotimia and type II.
4. Manic symptoms
The expansive, occasionally irritable mood is a common phenomenon of bipolar disorder in any of its subtypes . It is not an exultant joy, nor is it associated with a state of euphoria congruent with an objective fact, but it acquires an invalidating intensity and does not correspond with precipitating events that can be identified as its cause.
In the case of bipolar disorder type I, mania is a necessary symptom for diagnosis. It is characterized by a state of extreme expansiveness and omnipotence, resulting in impulsive acts based on disinhibition and a sense of invulnerability. The person becomes overly active, so involved in an activity that he or she forgets to sleep or eat, and engages in acts that involve potential risk or can have serious consequences.
In bipolar disorder type II the symptom exists, but it does not present with the same intensity. In this case there is a great expansion, in contrast to the mood that is usually shown, acting occasionally in an expansive and irritable way. Despite this, the symptom does not have the same impact on life as the manic episode, so it is considered a milder version of the latter. As with mania in bipolar disorder type I, hypomania is also necessary for the diagnosis of type II.
5. Psychotic symptoms
Most of the psychotic phenomena that are linked to bipolar disorder are triggered in the context of manic episodes . In this case, the severity of the symptom may reach the point of breaking the perception of reality, so that the person forges beliefs with delusional content regarding his or her abilities or personal relevance (considering oneself as someone so important that others must address him or her in a special way, or ensure that one has a relationship with well-known figures in art or politics, for example).
In hypomanic episodes, associated with type II, there is never enough severity for such symptoms to be expressed. In fact, if they do appear in a person with bipolar disorder, they suggest that the person is actually suffering from a manic episode, so the diagnosis should be changed to bipolar disorder type I.
6. Number of episodes
It is estimated that the average number of episodes of mania, hypomania or depression that a person will suffer over a lifetime is nine. However, there are clear differences between those who suffer from this diagnosis, which are due to both their physiology and their habits. Thus, for example, those who use illegal drugs have a higher risk of experiencing clinical shifts in their mood, as well as those with poor adherence to pharmacological and/or psychological treatment. In this sense, there are no differences between subtypes I and II.
In some cases, certain people may express a peculiar course for their bipolar disorder, in which a very high number of acute episodes can be observed, both of mania and of hypomania or depression. These are the fast cyclers, which present up to four clinically relevant turns in each year of their lives. This form of presentation can be associated with both type I and type II bipolar disorder.
After reading this article, many people may conclude that type I bipolar disorder is more severe than type II, since the intensity of the manic symptoms is greater there. The truth is that this is not exactly the case, and that subtype II should never be considered the mild form of bipolar disorder. In both cases there are significant difficulties in everyday life, and so there is a general consensus that they are equivalent in terms of severity.
While in subtype I the episodes of mania are more severe, in type II the depression is of obligatory presence and its duration is longer than in type I . On the other hand, in type I psychotic episodes may arise during the manic phases, which imply complementary perspectives of intervention.
As you can see, each type has its own particularities, so it is key to articulate an effective and personalized therapeutic procedure that respects the individuality of the person who suffers from them. In any case, the selection of a psychological approach and a drug will have to be adjusted to the assistance needs (although mood stabilizers or anticonvulsants are necessary), affecting the way in which the person lives with his mental health problem.
- Hilty, D.M., Leamon, M.H., Lim, R.F., Kelly, R.H. and Hales, R.E. (2006). A Review of Bipolar Disorder in Adults. Psychiatry (Edgmont), 3(9), 43-55.
- Phillips, M.L. and Kupfer, D.J. (2013). Bipolar Disorder Diagnosis: Challenges and Future Directions. Lancet, 381(9878), 1663-1671.