Increasing understanding of the bipolar spectrum of disorders has led to an increasing integration of concepts regarding the aetiology and treatment of affective disorders.

Thus, for example, we now understand that an illness, previously believed to be recurrent depressive disorder, may develop over time into a bipolar illness, and bipolar II illnesses may develop into bipolar I.

Agitated depression may in fact be a mixed affective state, and injudicious use of powerful antidepressants in patients with undiagnosed bipolar disorder may lead to the development of mixed states or rapid cycling illness, as well as a complete switch from depression to mania.

Mixed states and rapid cycling states are linked with increased suicidality.

Meanwhile bipolar disorder, especially bipolar II disorder, remains a condition which is underdiagnosed and often inappropriately treated.

Unfortunately, NICE guidelines are separate for Unipolar Depression and Bipolar Illness; those for Unipolar illness advocate a 'stepped care’ model, centred round primary care, while bipolar guidelines warn against injudicious use of antidepressants and the use of mood stabilisers to prevent ‘switching’ to mania.

Primary care physicians are not warned to take a full longitudinal history in depressed patients, to identify bipolar illness, nor are they trained to use mood stabilisers in patients with bipolar II disorder, and in the risks of injudicious use of antidepressants.

We need a single algorithm for identifying and treating affective disorders.

The symposium will consider these issues as a prelude to a Europe Wide meeting planned for later in 2009, to develop guidelines about these issues.