1 In 4 People Diagnosed With Depression May Have Bipolar Disorder, UK

As many as 1 in 4 people diagnosed in primary care with major depressive
disorder have been found to screen positive for a previous manic episode,
suggesting that they may actually have bipolar disorder rather than
depression.



Bipolar disorder is a serious and chronic psychiatric illness, associated
with high risk of suicide and other disorders. It is characterised by both
manic and depressive episodes.



Evidence shows that misdiagnosis of bipolar disorder is common, and that
the diagnosis is made, on average, as many as 10 years after the onset of
symptoms. The most common misdiagnosis is with unipolar depression, which
is characterised by depressed mood without manic episodes.



The aims of this study were to determine the proportion of patients who
are diagnosed with unipolar depression in primary care, but who actually
have bipolar disorder and may be receiving inappropriate and harmful
treatment. Evidence shows that some antidepressants can induce mania.



The cross-sectional survey of primary care patients is being conducted at
the Neasham Road surgery in Darlington in the UK. Those patients with
existing bipolar disorder were excluded from the study.



790 patients who had a diagnosis of unipolar depression using primary care
diagnostic methods were included in the study.



The researchers used 3 questionnaires:



- the Mood Disorder Questionnaire, designed to measure the rate of bipolar
disorder in the target group



- the Work and Social Adjustment Scale, designed to measure and compare
social functioning deficits between unipolar and bipolar patients



- the Cognitive Failures Questionnaire, designed to measure and compare
cognitive impairment between the 2 groups.



Evidence suggests that psychosocial and neurocognitive impairment may be
more pronounced in patients with bipolar disorder.



278 questionnaires were returned. Of these, 24% were found to have had a
previous episode of mania or mild mania. The researchers are currently in
the process of making a clinical diagnosis of these patients.



Subsequent interviews and analysis will provide information about the
prevalence of bipolar disorder in patients diagnosed with depression, and
about the occupational and neuropsychiatric impact of this disorder
compared with major depressive disorder.

Royal College of Psychiatrists