The Mysterious Disappearance of Unipolar Mania

Mania is is a mood state characterized by an elevated/euphoric, expansive, or unusually irritable mood lasting for at least one week and that is not the result of substance use. The irritability can also manifest itself as an increased impatience with others, heightened sensitivity to criticism (being "touchy"), or passive-aggressive behavior (opposition and stubbornness).

When occurring as a component of bipolar I disorder (a.k.a., manic depression), at least three symptoms from distinct triads among the following seven groups must also be present (DSM-IV-TR; APA, 2000):

(1)
(a) self-centered concerns and attitudes
(b) inflated self-esteem
(c) grandiosity

(2)
(a) heightened levels of energy
(b) a decreased need for sleep or frequent awakenings
(c) increased physical activity/feeling jumpy

(3)
(a) rapid abstract speech
(b) excessive talkativeness
(c) frequent interruptions

(4)
(a) racing thoughts
(b) abrupt changes of mind
(c) frequent shifts from one topic/task to another

(5)
(a) difficulty maintaining attention
(b) distractibility by irrelevant stimuli
(c) difficulties concentrating on essential tasks

(6)
(a) hyperfocus on non-essential tasks
(b) excessive and idealistic planning of future conduct
(c) psychomotor agitation or restlessness

(7)
(a) impulsive decision-making
(b) poor judgment
(c) reckless behavior

In bipolar II episodes of hypomania are present typically lasting at least one week. Hypomania is a milder state of mania in which the symptoms are not severe enough to impair daily functioning but are nonetheless observable by others.

Unipolar Mania?

The diagnostic criteria for bipolar disorder include symptoms of mania as well as symptoms of depressions--usually occurring at different times. Given this, it remains an interesting question what we should say about observed instances of unipolar mania.

Most bipolar researchers have nothing to say about unipolar mania. Yet the studies that have been conducted indicate that there are individuals with manic episodes and no depression.

However, the individuals with unipolar manic symptoms described in the literature present with clinical symptoms moderately different from those observed in bipolar mania.

Unipolar manic patients tend to exhibit more grandiosity (for instance, believing they are more intelligent or knowledgeable or better decision-makers than everyone else and deserve admiration), more psychotic symptoms (for example, believing they are rich and famous or have special powers), and a general tendency to have excess energy and be positive and enthusiastic. They furthermore normally remain in manic or hypomanic states for longer periods of time than bipolars. Unipolars are, on the other hand, less likely to be suicidal or have co-existing anxiety disorders.

The Mysterious Disappearance of Unipolar Mania

Yet unlike unipolar depression and bipolar disorder, unipolar mania is not a diagnostic category within psychiatry. It does not appear in the main diagnostic systems for psychiatric disorders and have received very little attention by clinicians and researchers.

This has not always been the case. German psychiatrist Emil Kraepelin (1899) used the term "periodic mania" to refer to people recurrent manic episodes without depression. Around the same time German scientist Carl Wernicke (1900) proposed that single or recurrent episodes of mania or depression should be viewed as distinct disorders. The terms "phasic psychoses” and "pure phasic psychoses" were introduced by German neurologist Karl Kleist (1911, 1953) and his student Karl Leonhard (1957) to describe unipolar mania and unipolar depression.

If unipolar mania was once widely recognized as a disorder separate from depression, why did the term all of a sudden disappear from the vocabulary of most clinicians and researchers?

A widely held view is that unipolar mania does not, and cannot, exist as a separate mental disorder because its symptoms vary too greatly across different individuals to define a unified clinical entity. As a consequence, when symptoms suggestive of unipolar mania give rise to distress severe enough to seek help, the condition is commonly classified and treated as bipolar disorder with mild unnoticeable or agitated depressive symptoms. The latest diagnostic manual for psychiatric illness (DSM-V) even explicitly states that individuals whose functionality is impaired by manic episodes without depression should be diagnosed with bipolar I.

A further reason why unipolar mania is not officially recognized as a diagnostic condition separate from bipolar disorder is that very few studies of the syndrome have been conducted. As a result, there is no consensus regarding the diagnostic criteria or its prevalence.

Scientific Evidence for Unipolar Mania

Despite the skeptical stance toward unipolar mania, there are independent neurobiological findings that clinicians and researchers ought to recognize a psychiatric condition characterized by some of the symptoms of bipolar manic episodes yet belonging to a separate clinical category.

One significant finding is that individuals with unipolar depression and bipolar individuals have a larger than normal third ventricle (bounded by the thalamus and hypothalamus on both the left and right sides). This enlargement suggests that depression may be due to an inflammation of the brain in these regions. No similar enlargement of the ventricles has been found in patients with unipolar mania.

There is also pharmacological evidence for a clinical entry for unipolar mania that is distinct from bipolar mania. Whereas bipolar patients often benefit from treatment with lithium salt, a mood stabilizer, symptoms of unipolar mania do not seem to improve with lithium treatment.

If unipolar mania and bipolar disorder are distinct biological diseases with distinct underlying neurobiological mechanisms, then unipolar mania that impairs functionality deserves its own clinical entry in diagnostic manuals.

What Kind of Biological Disease Is Unipolar Mania?

As we have seen, there is some evidence that unipolar mania and bipolar disorder are distinct biological diseases. But if this is so, then new puzzles arise. One is that of explaining what kind of biological disease unipolar mania is. A second is that of explaining why the symptoms of bipolar manic episodes rarely (if ever) occur without depression.

A radical suggestion addressing the first puzzle is that unipolar mania is a subtype of attention-deficit hyperactivity disorder, or ADHD. Unipolar mania and ADHD both present with symptoms such as a tendency to be talkative and frequently interrupting others, an increase in energy or activity, impulsivity, difficulties paying attention and being easily distracted.

The main difference between unipolar mania and ADHD is that symptoms of the former condition typically occurs in episodes, whereas symptoms of ADHD are chronic (at least during childhood, although they may improve or disappear as the child matures). However, this difference should not be the single reason for ruling out that unipolar mania may be biological subcategory of ADHD.

The hypothesis that unipolar mania is a kind of ADHD is supported by the finding that defects in the white matter of the prefrontal cortex occur both in adults with recurrent manic episodes and in children with ADHD. It is also telling that children with ADHD are more likely to develop bipolar disorder as young adults than children who have not been diagnosed with ADHD.

The most convincing evidence for the hypothesis that unipolar mania is a subtype of ADHD turns on the fact that the latter condition itself divides into subtypes. The most commonly discussed is the hyperactive-distractible type. When ADHD persists into adulthood, however, hyperactivity often decreases and is replaced by what we might call the intermittently hyperfocused subtype (also sometimes referred to as the hyperattentive/flow subtype and ADD with perseveration; Webb, et al. 2005).

The following is a comparison of the symptoms of the hyperactive-distractible subtype and the intermittently hyper-focused variety. Of course, these symptoms can be present in varying degrees.

Hyperactive-Distractible Intermittently Hyperfocused

Inattentiveness Difficulty in directing (and redirecting) attention
Distractibility Cycling hyperfocus and distractibility
Hyperactivity Trance-like daydreaming
Procrastination Procrastination
Impulsivity Impulsivity/poor decision-making
Irritability or "acting out" Irritability or impatience
Disorganized Disorganized
Forgetful Forgetful
Regulated by fear of punishment Regulated by fear of failure and embarrassment
Constantly switching tasks Difficulties switching tasks

Unipolar manic episodes appear to have much more in common with the intermittently hyperfocused ADHD subtype than the hyperactive-distractible variety.

The main characteristics of unipolar mania that seem to be lacking in ADHD are mood elevation and heightened self-esteem/grandiosity. Researchers and clinicians sometimes regard these differences to be the main factors that mark the distinction between mania and ADHD.

As it turns out, however, these differences do not form a good basis for assigning the mania and ADHD to different clinical categories. Here are four reasons.

(i) Mood elevation is only one way in which mood can undergo alteration in manic episodes. Increased irritability is at least as common as euphoria/elevated mood, and irritability is a common symptom in ADHD.

(ii) Grandiosity, or heightened self-esteem, sometimes occurs in ADHD patients who are successful because of (or in spite of) their hyperfocus.

(iii) Hyperfocus together with inattentiveness to other people could easily be mistaken for high self-esteem or grandiosity in patients with hyperfocus.

(iv) Grandiosity is not a required or a frequent symptom of bipolar mania. With more research, it may be found that it is not that prevalent in the unipolar mania either.

Why Do the Symptoms of Bipolar Manic Episodes Rarely Occur Without Depression?

Unipolar mania by definition occurs without depression. So, if unipolar mania and bipolar are distinct clinical conditions, the question arises why the symptoms of bipolar manic episodes rarely occur without depression?

Or to put the question differently: why think that the symptoms of unipolar manic episodes are significantly different from those of bipolar manic episodes?

The most likely (yet unexplored) explanation is that during a manic episode in bipolar I disorder, the brain's levels of the neurotransmitter dopamine are elevated. This can explain the euphoric (or irritable) mood, the increased energy and activity as well as the heightened self-esteem.

But once the brain levels of a neurotransmitter have been elevated for a while during a long episode, the brain tends to accommodate by down-regulating the receptor sites the chemical binds to. When there are fewer receptor sites for the chemical to bind to, the chemical will no longer provoke a cell response that triggers manic symptoms.

If the dopamine receptors become heavily down-regulated, which is likely to happen sooner or later, the low brain levels of dopamine can lead to a feeling of emptiness, a lack of motivation, a decreased ability to experience pleasure as well as negative feelings such as angst and irritability. But these latter symptoms are among the typical depressive symptoms that occur in bipolar disorder.

Why Is Unipolar Mania Cyclic When ADHD is not?

If unipolar mania is not really mania but ADHD with hyperfocus, the question arises why we don't see a waning of symptoms in unmedicated patients with ADHD with hyperfocus. Why is the latter condition not episodic or cyclic?

The most likely reason is that the neurotransmitter deficits differ in manic bipolar episodes and ADHD with hyperfocus (a.k.a. unipolar mania). It has long been established that individuals with ADHD have lower than normal levels of dopamine in the prefrontal cortex (rather than an excess as in bipolar mania). Overmedicating with stimulants raising dopamine levels could result in a down-regulation of dopamine receptors in the brain and an eventual return of ADHD symptoms--possibly accompanied by depressive symptoms. But normalizing the brain's levels of dopamine should not result in down-regulation. The difference in dopamine systems in manic bipolar ADHD with hyperfocus (a.k.a. unipolar mania) then can explain why ADHD with hyperfocus, unlike bipolar mania, normally doesn't cycle.

Berit "Brit" Brogaard is a co-author of The Superhuman Mind.