BIPOLAR DISORDER, TYPE II...WHY IT IS IMPORTANT

Bipolar II disorder [I will refer to this as BP2 for rest of blog] made the news when it was reported that the actress Catherine Zeta-Jones was given this diagnosis.  Most people are aware of bipolar I disorder [BP1] yet BP2 is more prevalent and has significant levels of morbidity [the impact of the illness on one's life] and mortality [it can lead to suicide].  Also, and very importantly, BP2 is often misdiagnosed as frequently people with BP2 initially present to general medical settings and not psychiatric settings where they are likely to be diagnosed with a major depression and treated with antidepressants.  This happens in psychiatric settings as well.

BP2 is diagnosed if someone has had one or more major depressive episodes [MDEs] with at least one hypomanic episode.  In contrast, someone with BP1 has had at least one manic episode and usually one or more MDEs.  Differentiating BP1 from BP2 requires being able to determine if there has been a manic episode vs only hypomanic episodes.  Manic episodes involve periods of persistent and abnormally elevated, expansive or irrirtable mood  lasting at least one week.  Change in mood must be accompanied by at least three of the following if mood is elevated and at least four if mood is irritable. These include: 1. inflated self-esteem or grandiosity, 2. decreased need for sleep, 3. more talkative than usual, 4. flight of ideas or the subjective experience that thoughts are racing, 5. distractibility, 6. increase in goal-directed activity or psychomotor agitation [very restless and anxious], and 7. excessive involvement in potentially dangerous activities.  The manic mood causes impairment in functioning. Hypomanic episodes involve a period of persistently elevated, expansive or irritable mood, lasting for at least four days and it is clearly different from the person's typical depressed mood. The hypomanic mood is accompanied with the same list of possible symptoms as for manic epsiodes and must be clearly a change in functioning and observable to others but not to level of impairment. 

Another very important distinction must be made between BP2 and Major Depressive Disorders [MDD] as they do not involve any hypomanic episodes, while BP2 involves MDEs and hypomanic episodes.  If someone presents with an MDE, the only way to determine if they have BP2 is to find out if they have had any hypomanic episodes in the past.  This can be difficult as often people do not consider hypomanic episodes as problematic or pathologic and may not recall them even with direct questioning.  This is one reason that it can take over ten years to correctly diagnosis BP2.  I have treated people who have had seven different trials of antidepressants with an initial improvement and then worsening of their moods only to try another antidepressant.  This can lead to a lot of suffering and risk of suicidal behavior.  

So, how common is BP2? Lifetime prevalence rates in the US = 1.1%.  It often is associated with panic disorder, substance use disorders and ADHD.  Importantly, the depressive episodes for BP 2 compared to those for MDD were associated with more suicidal thoughts, hypersomnolence [increased sleeping] and higher rates of agitation. BP2 moods are also more seasonally influenced [more depression in later fall and winter].

Therefore, while there are some things that distinguish BP2 depression from MDE depression, the diagnosis still rests on identifying hypomanic episodes.  Be alert for these in anyone you know who has had a MDE as early treatment can make a big difference in quality of life for those with BP2.