All patients with depression should be screened for bipolar spectrum disorders, argues GP Dr Tom Shackleton
Bipolar affective disorder type 1 (depression alternating with mania) and BPAD type 2 (depression alternating with hypomania) affects about 4% of the population. 'Bipolar spectrum' patients do not meet the criteria for BPAD 1 or 2 diagnoses but display mild transient hypomania. There is increasing consensus that this is a specific sub group of unipolar depressive patients with different responses to treatment.
Many patients suffering with bipolar disorder presenting with depressive features, and the clinical issue here is that there is a risk of harm from standard antidepressant therapies in BPAD 1 and 2. They can cause destabilisation of mood and possibly increased suicidal behaviour in younger BPAD patients.
Depressive symptoms are a common presentation in general practice, but patients may not be overly keen on discussing some of their manic features or have little insight, and collateral information from family may not always be available to the GP.
The majority of cases of depression are managed in primary care so GPs are in a vital position for picking up bipolar symptoms and referring appropriately and potentially making a significant improvement in patients' quality of life.
Unfortunately, the predominance in depressive features at the time of consultation, QOF incentivising depression severity assessments and time pressures may make us 'depression-centric' in our consultations. What we should be doing is including assessment tools for bipolar affective disorder spectrum symptoms in all initial assessment appointments with patients presenting with depressive symptoms and when reviewing those not responding to antidepressant treatment or having recurrent episodes of depression. Those screening positive should be considered for formal specialist assessment.
The bipolar spectrum diagnostic scale and the mood disorder questionnaire are practical possibilities as tools to aid the busy GP or Psychologist in IAPT services in screening for bipolar symptoms. A recent expert group had suggested adding two screening questions to the PHQ9 questionnaire. An abbreviated version of the hypomania checklist is currently in development.
If specialist assessment leads to a diagnosis of BPAD, mood stabilisers such as lamotrigine and atypical antipsychotics such as quetiapine can be considered as alternative therapeutic options. These can then be discussed with patients. There is little evidence base yet for the use of mood stabilisers and atypical anti-psychotics in bipolar spectrum disorders but these could be considered as therapeutic options under specialist supervision.
This is a reminder of the importance of reviewing diagnoses if patients are not improving or responding unusually to treatments rather than just looking at different antidepressants.
Dr Tom Shackleton is a GP in Cambridge with a special interest in mental health and GP advisor to NICE depression guideline development group.Dr Tom Shackleton