In the past, doctors were accused of being under-sensitive to the signs of bipolar disorder. More recently, the numbers of people diagnosed with bipolar have steadily climbed, leading to the accusation that doctors are now over-sensitized. There's a problem here and it is not just about diagnostic trends and bandwagons. Screening and diagnostic practices for bipolar disorder remain patchy and this is due, in part at least, to blurry boundaries that can exist between conditions.

Take a look at any forum relating to depression and / or bipolar disorder and a theme begins to emerge. First, there is the person who has been diagnosed with unipolar depression wonders if they actually have bipolar depression. Secondly, the reverse scenario, in which having been diagnosed with bipolar disorder the person wonders if they really should be considered as suffering with unipolar depression? How do these issues come about?

If we consider each in turn the cloud of confusion begins to dispel. Why might a person who can only ever recall being depressed being receiving medication normally usually prescribed for bipolar disorder? The answer should be fairly simple. A diagnosis of bipolar disorder can only be made if the person has experienced at least one episode of hypomania or mania. And this is where it gets messy. Diagnosing mania is far easier than its milder cousin hypomania (hypo meaning less than or under) and it is just possible that the extra energy and 'high' felt by someone emerging from a period of depression is actually what the rest of us might regard as normal. Then again, treatment with lithium, the standard medication for mood disorders such as bipolar disorder, can sometimes be prescribed as a catalyst for people who are unresponsive to standard antidepressants.

According to the definition of hypomania, which goes along the lines of, 'a distinct period of persistently elevated, expansive, or irritable mood, lasting at least four days, that is clearly different from the usual non depressed mood,' a distinguishing feature is that the mood does not change in the light of good or bad circumstances. Coach and horses come to mind with this concept. It seems to me that four days is a very narrow window in which to pass such a judgment. Add the issue of good or bad circumstances and I think we've got a bigger problem. Most people live rather predictable lives that rarely involve especially good or bad circumstances. Even if such circumstances were to occur, the idea that they would conveniently overlap a four-day period of expansive or irritable mood sees absurd. Establishing 'normal' when it comes to mood is a highly subjective issue at the best of times. Establishing what is 'elevated' compared to someone who is almost always depressed must be spectacularly difficult.

Let's now consider the issue of the person diagnosed with unipolar depression who wonders if they may actually have bipolar disorder? The same rules, or problems sometimes, apply. How do we know whenever the periods of relief from depression simply elevate the mood to a rare and unusual place? Happiness is normal after all so do not people starved of this most elemental quality have the right to immerse themselves in it when it comes their way.

Diagnosing bipolar disorder is a complex process that involves time and symptom elimination. Until recently, most people diagnosed with bipolar disorder waited an average of ten years before their symptoms were recognized for what they were. It's a process where patients and clinicians have to work together but being careful not to pathologize behavior simply because it is rare or unusual.