As many as one in four people diagnosed with depression may actually be suffering from bipolar disorder, a new study suggests.
The research, involving 790 primary care patients diagnosed with unipolar depression, was carried out at the Neasham Road surgery in Darlington.
Some 24 per cent had experienced a previous episode of mania or mild mania.
Their findings tally with previous studies, which showed that bipolar disorder is regularly diagnosed long after its onset. In some cases, patients are left without help for many years.
Bipolar disorder is a chronic psychiatric condition, associated with high risk of suicide and characterised by both manic and depressive episodes.
Symptoms of depression include lasting sadness or anxiety; pessimism; loss of interest or pleasure in activities; abnormal sleeping patterns, and irritability.
Meanwhile, symptoms of bipolar disorder include high energy and/or activity levels; talking quickly; aggressive behaviour; sleeping little, and extreme irritability.
The researchers are currently working towards a clinical diagnosis and hope to perform further interviews in the future.
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