Bipolar disorder is a chronic mental health disorder characterised by periods of mania/hypomania alongside episodes of depression.


Two types of bipolar disorder are recognised:
  • type I disorder: mania and depression (most common)
  • type II disorder: hypomania and depression


  • Incidence: 25.00 cases per 100,000 person-years
  • Peak incidence: 20-30 years
  • Sex ratio: 1:1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+

Clinical features

What is mania/hypomania?
  • both terms relate to abnormally elevated mood or irritability
  • with mania there is severe functional impairment or psychotic symptoms for 7 days or more
  • hypomania describes decreased or increased function for 4 days or more
  • from an exam point of view the key differentiation is psychotic symptoms (e.g.delusions of grandeur or auditory hallucinations) which suggest mania


  • psychological interventions specifically designed for bipolar disorder may be helpful
  • lithium remains the mood stabilizer of choice. An alternative is valproate
  • management of mania: consider stopping antidepressant if the patient takes one; antipsychotic therapy e.g. olanzapine or haloperidol
  • management of depression: talking therapies (see above); fluoxetine is the antidepressant of choice
  • address co-morbidities - there is a 2-3 times increased risk of diabetes, cardiovascular disease and COPD


Primary care referral
  • if symptoms suggest hypomania then NICE recommend routine referral to the community mental health team (CMHT)
  • if there are features of mania or severe depression then an urgent referral to the CMHT should be made