Worsening Over Time: The Progression of Bipolar Disorder

In some people, bipolar disorder gets worse over time. Not everyone. And treatment is supposed to prevent this, at least in the best of cases.

The graph above shows one hypothetical patient's experience, where depression is shown as a bar below the line, a manic episode as a bar above the line, and hospitalizations in red. The height of the bar indicates the severity of the episode. Fortunately, few cases are as bad as this, but the pattern is obvious -- and that pattern is very common.

In Bipolar I, where episodes tend to be separated by "well intervals", one can see a progression like the one shown above: episodes become more severe, and the length of time in between episodes become shorter. In Bipolar II, more continuous symptoms are common. In this case, illness progression is characterized by an increasing severity of mood swings, and sometimes more rapid cycling. In many people, manic and depression symptoms occur at the same time, and what is called a "mixed state". In other words, the pattern shown in the graph above is not easily seen in people who have more complex and mixed symptoms. Yet the progression toward more severe symptoms over time is still going on.

Unfortunately, this also means that sometimes a treatment which worked at one point is no longer sufficient to provide complete symptom control later. Sometimes a person who symptoms were quite well-controlled on one medication ends up on three a few years later.

What causes this progression? This is not well understood, in part because we do not know what causes the illness itself; we do not know what the molecular and genetic basis of bipolar disorder is (although we know a lot more than we did 10 years ago, as outlined on my webpage about "what causes bipolar disorder?"). However, we do know some of the factors which seem to influence whether people experience this can progression or not, and how fast.

Basically, mood specialists currently presume that anything which has a "destabilizing influence" is likely to be one of the causes of progression. You can imagine how hard it is to do research on this: people continue to live their lives, and thus expose themselves to all sorts of influences. How could you tell whether the influence you are studying was truly the "cause" of worsening? There are always too many variables to really know.

For now, we are extrapolating from our experience with the obvious triggers. Probably the biggest one is substance use. Methamphetamine and cocaine might be the worst. Alcohol comes along shortly after that: even though in the short run it can damp down symptoms, in the long run it tends to cause more cycling in most people. Pain medications are not as bad, and it seems, at least in our current understanding. They can cause trouble in some people but nowhere near as often as street stimulants and alcohol.

What about marijuana? Evidence has accumulated that this can lead to psychotic episodes in susceptible individuals. In Bipolar I, therefore, it might be best avoided entirely. At the same time, many patients who see me in our local free clinic have been using marijuana for years, just a puff or two at night, because they have found that it helps them sleep. They are quite certain they would be worse without it, although they tend to give it up if they get a very good response to a mood stabilizer medication (in which case I can claim"my drugs are better than your drugs").

The other big destabilizing influence is sleep deprivation. People who take on erratic schedules, such as shift work, often see a dramatic worsening in mood stability. Even just a plane flight across time zones can be a major trigger in some susceptible individuals. Evidence is accumulating that careful attention to sleep schedule, and even light exposure, is very important in self-management of bipolar disorder. See my essay on Light and Darkness in Bipolar Disorder for some interesting data about the role of darkness independent of sleep.

Finally,without necessarily having exhausted this list, a word about antidepressants. One of my greatest fears about current psychiatric practice is that 10 years or more from now we might discover that widespread use of antidepressants has led to an acceleration in bipolar progression in people receiving these medications, in those who were later discovered to have bipolar disorder (let alone those who were known at the time to have bipolar disorder). This acceleration has been called "kindling", after a similar phenomenon seen in epilepsy. I sure hope that I'm wrong about this. Until we have a good biological marker of Bipolar Disorder which can show us where a person is on this illness progression, so that we might be able to see -- literally -- progression associated with antidepressants, this kindling worry is likely to remain just that, a background worry, not a known problem. See more about this on my page about Antidepressant Controversies, the section on kindling.

(This entry was composed in response to a reader's request for information on this topic. Thank you for the inquiry)

Dr. Phelps