Bipolar

• Overview:

  • Bipolar disorder is a mood disorder characterised by episodes of depression and mania, or hypomania
  • Much lower prevalence than unipolar depression
  • Bimodal distribution, two peaks 15-24 and 45-54 years
  • Roughly equal distribution between men and women
  • Commonly seen in conjunction with other mental health illness
  • Increases a persons risk of physical health issues
• Aetiology:

  • Complex interaction between genetic, environmental and neurobiological factors
  • Genetic - first degree relatives of a person affected at at increased risk. Type of polygenic inheritance - polymorphisms in genes that code for monoamine transporters and brain-derived neurotropic factor (BDNF)
  • Environmental - not specific to this condition - negative life events
  • Neurobiological factors - Some evidence that increased dopamine is important in mania . There are also disturbances of the hypothalamic-pituitary-adrenal axis, resulting in increased cortisol secretion
• Risk factors:

  • Genetic - may single nucleotide polymorphisms
  • Prenatal exposure to Toxoplasma gondii
  • Premature birth <32 weeks
  • Childhood maltreatment
  • Postpartum period
  • Cannabis use
• There are several types of bipolar disorder and the clinical features differ between each. The two main forms of the disorder are bipolar I and bipolar II:

  • In bipolar I, the person has experienced at least one episode of mania
  • In bipolar II, the person has experienced at least one episode of hypomania, but never an episode of mania. They must have also experienced at least one episode of major depression.
• cyclothymia is a related disorder characterised by a persistent instability of mood involving numerous periods of depression and mild elation, none of which are sufficiently severe or prolonged to justify a diagnosis of bipolar affective disorder or recurrent depressive disorder.
• Characteristic clinical features of mania are elevated mood, increased activity level and grandiose ideas of self-importance:

  • Elevated mood out of keeping with the patient’s circumstances
  • Elation accompanied by increased energy resulting in overactivity, pressure of speech, and a decreased need for sleep
  • Inability to maintain attention, often with marked distractibility
  • Self-esteem which is often inflated with grandiosity and increased confidence
  • Loss of normal social inhibitions
• Diagnosing mania:

  • Episodes should last for at least 7 days
  • Have a significant negative function effect on work and social activities
  • Mood changes should be accompanied by an increase in energy and several other symptoms
  • Mania can also occur alongside psychotic symptoms - often delusions and auditory hallucinations
• Hypomania:

  • Less severe than mania and characterised by an elevation of mood to a lesser extent
  • Persistent, mild elevation of mood
  • Increased energy and activity, usually with marked feelings of wellbeing
  • Increased sociability, talkativeness, over-familiarity, increased sexual energy and decreased need for sleep (but no significant negative effect on functioning)
  • Irritability may be present
  • Absence of psychotic features
  • For a diagnosis, more than one of these features should be present for at least 4 days
• Investigations:

  • Can be used to exclude organic causes of a patients clinical presentation
  • Bloods - FBC, U&Es, LTFs, TFTs, CRP, B12, folate, vitamin D
  • HIV
  • Toxicology
  • Neurological examination
  • CT head
• Diagnosis:

  • Mania: symptoms should have lasted for at least seven days
  • Hypomania: symptoms should have lasted for at least four days
  • Depression (characterised by low mood, loss of interest or pleasure, and low energy) with a history of manic or hypomanic episodes
  • To confirm diagnosis a referral should be made to a specialist mental health service
• Acute management of mania:

  • People with a new diagnosis of bipolar disorder should be managed in secondary care with a trial of oral antipsychotics
  • First line antipsychotics - haloperidol, olanzapine, quetiapine or risperidone
  • Any antidepressant medication should be tapered off and discontinued - can worsen mania
  • Benzodiazepines may be used to manage symptoms of increased activity and insomnia
  • Second line - lithium
• Management of acute depressive episode:

  • Standard antidepressant management options can be associated with lower efficacy compared to unipolar depression, can also increase risk of inducing mania or rapid cycling
  • Fluoxetine combined with olanzapine, or
  • Quetiapine alone
  • Psychological interventions such as CBT may be useful
• Long term management of bipolar disorder:

  • Mood stabilising medication - first line lithium
  • If lithium is not effective, sodium valproate may be added
  • Lithium is associated with a significant reduction in the risk of relapse of with a manic episode
  • Lithium is associated with a significant reduction in death by suicide
  • Structured psychotherapies such as CBT
• Lithium:

  • Serum lithium levels (taken 12 hours after the most recent dose) are closely monitored - 5-7 days after starting or dose increase, and 3 monthly to begin with
  • Usual target range is 0.6-0.8 mmol/L
  • Lithium toxicity can occur if the dose and levels are too high
  • Potential side effects:
  • Fine tremor
  • Weight gain
  • CKD
  • Hypothyroidism and goitre (inhibits production of thyroid hormones)
  • Hyperparathyroidism
  • Nephrogenic diabetes insipidus
• Lithium toxicity symptoms:

  • Gastrointestinal - vomiting, diarrhoea
  • Visual disturbances
  • Polyuria
  • Muscle weakness
  • Tremor
  • CNS - confusion, drowsiness
  • Abnormal reflexes - hyperreflexia
  • Severe - seizures, arrhythmias, coma, sudden death
• Lithium:

  • Mood stabilizer. antimanic
  • Inhibition of norepinephrine and dopamine release in the brain, increased serotonin production, alteration of sodium and potassium ion transport
  • Contraindications: Addison's disease, cardiac disease associated with rhythm disorder, dehydration, Brugada syndrome, untreated hypothyroidism
  • Avoid in breast feeding and severe renal impairment
• Complications of bipolar:

  • Increased risk of death by suicide
  • Increased risk of death by general medical conditions such as cardiovascular disease
  • Side effects of antipsychotic drugs: these can include metabolic effects, weight gain and extrapyramidal symptoms
  • Socioeconomic effects: major mental illness is associated with a negative drift down the socioeconomic ladder
• Rapid-cycling bipolar disorder is defined as the experience of at least four depressive, manic, hypomanic, or mixed episodes within a 12-month period.
• Bipolar I is the most common type and is more common in males

  Bipolar II is more common in females
• ICD-11 bipolar I:

  • A history of at least one manic or mixed episode
  • Although a single manic or mixed episode is enough for diagnosis, the typical course of the disorder is characterized by recurrent depressive and manic or mixed episode
• ICD-11 Bipolar II:

  • A history of at least one hypomanic episode AND
  • A history of at least one depressive episode
  • No history of manic or mixed episodes