Psychiatry - Mood disorders Flashcards
What is the ICD-10 criteria for depression?
3 core symptoms, at least 2 of which should be present every day for at least 2 weeks:
- low mood
- anhedonia (= loss of enjoyment in formerly pleasurable activities)
- decreased energy or increased fatiguability
What determines the severity of a depressive episode?
Depressive episodes are described as mild, moderate or severe. They depend on:
- number of symptoms present (core + additional)
- severity of the symptoms
- degree of associated distress
- interference with daily activities
Other than core symptoms, give some additional symptoms of depression
- reduced concentration and attention
- disturbed sleep and/or appetite
- reduced self esteem
- ideas of guilt and worthlessness
- thoughts of hopelessness
If a depressive episode has psychotic features how should it be classified?
Any depressive episode associated with psychotic features (i.e. first rank symptoms) is automatically classed as severe.
What is a unipolar mood disorder?
This is a mood disorder characterised by recurrent depressive episodes only.
cf. bipolar mood disorders if there is a history of at least one manic or hypomanic episode
Thought content in depressed patients
Clinical features of depression include thought content, biological symptoms, altered motor activity, cognition, psychotic features etc.
Thought content in depression often includes negative, pessimistic thoughts about:
- the self (low self esteem)
- the world
- the future
These 3 subjects are referred to as Beck’s cognitive triad. There may also be feelings of worthlessness and thoughts about self harm (risk assessment important)
Biological symptoms of depression
Biological symptoms refer to reduced sleep, appetite and libido. These may be particularly prominent in older people, who less often complain of disturbed mood.
There is often a sleep pattern of early waking (more than 2 hours before usual) and maximal lowering of mood in the morning (diurnal variation).
Poor appetite may be associated with weight loss.
Psychotic features in depression
Psychotic features may occur in depression (and bipolar). First rank symptoms are usually mood congruent.
Delusions are usually nihilistic (e.g. a belief that one is dead, has lost all ones assets or ones body is rotting), hypochondriacal, concerning illness or death.
When hallucinations occur, they are usually auditory, in the second person and accusing, condemning or urging the individual to commit suicide.
What is atypical depression?
This is a form of depression that most often occurs during adolescence. It features initial anxiety related insomnia, subsequent oversleeping, increases appetite and a relatively bright and reactive mood.
What are the differential diagnoses to consider in depression?
- normal sadness, particularly in the context of bereavement or severe physical illness
- psychotic depression should be differentiated from schizophrenia on the basis of thought content (mood congruent first rank symptoms) and the time sequence in which symptoms develop
- Alcohol or drug withdrawal
- Depressive retardation may be difficult to distinguish from the flat (unreactive) affect of chronic schizophrenia
Epidemiology of depression
Lifetime risk is 10-20%, with rates almost doubled in women.
First onset is typically in the third decade (cf. bipolar disorder which is earlier).
Depression is strongly associated with low SES.
What is the aetiology of depression?
Twin and adoption studies show that there is a genetic component to depression, but this is less prominent for unipolar than bipolar depression.
Current theories suggest a gene-environment interaction - i.e. a genetic predisposition to depression if exposed to adverse life events or social circumstances. These include:
- parental loss, stress, abuse in childhood
- alcohol/ drug abuse (depression is often comorbid)
- severe physical illness, some medications (e.g. steroids, isotretinoin)
- life event (e.g. bereavement), deprivation, adversity, unemployment, lack of a confiding relationship
What is the final common pathway in the aetiology of depression?
Gene-environment interactions suggest that the final common pathway in depression is decreased brain derived neurotropic factor (BDNF) that promotes neurogenesis.
This is caused by increased cortisol (hypercortisolaemia) and decreased central synaptic monoamine levels (i.e. noradrenaline and 5-HT).
Reduced BDNF may be particularly important in the limbic system and prefrontal cortex.
What is the management of mild depression?
Most cases of depression can be managed in primary care. Psychiatric referral is only indicated if suicide risk is high, or the depression is severe, unresponsive to treatment, bipolar or recurrant.
For mild depression:
- self help groups
- structured physical activity groups
- guided self help groups
- behavioural couples therapy
NB - antidepressants are not indicated for mild depression
How should moderate depression (and mild depression not responding to treatment) be managed?
Psychological therapy should be given with antidepressants for moderate or severe depression. These can have a 60-70% response rate, but often fail because of inadequate dosage, duration or adherence.
So:
- add antidepressant
- individual CBT
- interpersonal therapy
Treatment for severe cases of depression
Remember that multiple factors determine the severity of a depressive episodes (esp. number of core + additional symptoms).
For severe depression:
- ECT if poor oral intake, psychosis, or stupor present
- atypical antipsychotics (e.g. aripiprazole, olanzapine, risperidone, quitiapine) if psychotic
- augment antidepressants with lithium or an atypical antipsychotic if depression resistant
How long should a patient stay on antidepressants after a depressive episode?
Continuing antidepressants for at least 6 months reduces relapse. In recurrent depression, prophylactic effects have been demonstrated for up to 5 years.
When discontinuing antidepressants, taper slower to avoid withdrawal symptoms.
What is the prognosis for depression?
Single episodes of depression usually last several months.
About:
- 20% of patients remain depressed for 2 years or more
- 50% have recurrences, rising to 80% in severe cases
The lifetime suicide risk is 15% in severe depression, but much lower in milder illness.
Predictors of poor outcome include early onset, greater symptom severity and psychiatric or physical comorbidity.
What is bipolar disorder?
Also known as manic depression
Involves recurrent episodes of both depression and mania. Recovery between episodes is usually complete and the frequency and pattern of episodes is variable
Aetiology of bipolar
Genetic factors have a strong contribution:
- heritability is estimated at 85%
- MZ:DZ = 80:20%
- risk of bipolar illness in a first degree relative of those with bipolar is 8%
What risk factors are associated with bipolar disorder?
High SES Urban areas Ethnic minority groups Increased risk of manic episodes in post partum period Sleep disturbance caused by shift work Equally common in men and women
Clinical features of hypomania
Persistent elevation in mood (> 3days) Increased activity and energy Decreased sleep Talkative Overfamiliarity Increased libido
What is the difference between mania and hypomania?
Elevated mood with psychotic symptoms distinguishes mania from hypomania
- delusions are usually congruent (grandiose)
- auditory hallucinations may be present
Mania can occur WITHOUT psychotic symptoms
Examination findings in bipolar disorder
Appearance and behaviour: Dress inappropriate/ outlandish, may be neglect of personal hygeine, overfamiliar, flirtatious behaviour, increased psychomotor activity, distractible
Speech: load, pressure of speech, flight of ideas
Emotions: elated but can quickly turn to irritability and anger
Perceptions: auditory hallucinations, often mood congruent
Thoughts: grandiose or persecutory
Insight: poor
Cognition: attention and concentration often impaired
What investigations should be performed in bipolar?
Exclude other causes of manic episodes: substance misuse, space occupying lesion, hyperthyroidism, corticosteroids, anabolic androgenic steroids
FBC, U&E, LFTs, Ca, TFTs, glucose, urine drug screen
Management of an acute manic episode
Most patients require hospitalisation - use MHA if poor insight
Lithium is mood stabiliser. It takes 3-7 days to take effect, so antipsychotics are required for rapid control of acute behavioural disturbance
BDZ can be used as adjunct
Olanzapine can also be used as mood stabiliser, also has sedating effects
ECT if exhaustion becomes life threatening
Antidepressants can precipitate or aggravate a manic episode, so are stopped
When should patients be offered prophylaxis for bipolar and how is this achieved?
One episode of mania at an early age is an indication for prophylactic treatment
Li and sodium valproate are mood stabilisers and are main treatments used to prevent relapse. They help to prevent both depression and mania
Advise women about contraception
Before starting lithium check renal function and TFT. Lithium has a narrow therapeutic range and levels should be checked carefully
Olanzapine can be used for prophylaxis
Carbamazepine and lamotrigine are also effective and may benefit some responder
What complications are associated with bipolar disorder?
10% of patients with bipolar commit suicide
Alcohol and substance abuse can complicate the picture
Non compliance with prophylaxis is an important issue
Patients often don’t comply due to the side effects or a prolonged period of well being. Abrupt withdrawal of a mood stabiliser carries a high risk of relapse of mania and/or depression (50% of patients relapse within 5 months if lithium is stopped)
Minority of patients develop rapid cycling of four or more episodes a year
What is the prognosis of bipolar disorder?
Most relapses are associated with poor compliance
90% of patients will have at least one recurrence of mania and/or depression within 10 years
Median duration of an untreated manic episode lasts 4 months, depression is slightly longer at 6 months. Usually with time, manic episodes become less frequent, depressive episodes last longer
What factors are associated with a poor prognostic outcome for bipolar?
Early onset of illness Poor compliance Persistant depressive symptoms Severe mania FHx of non response Co-morbid personality Substance misuse Rapid cycling (four episodes per year)
