Drugs used in Affective Disorders Flashcards
What kind of disorder in depression ?
Affective Disorder - disorder of mood rather than thought or cognition.
What is the prevalence of depression ?
Lifetime prevalence of about 25% - primary mental disorder by 2030
What is the proportion of suicide attempts amongst depressed individuals ?
How effective is treatment ?
About 20% attempt suicide
About 5-10% succeed (5602 in UK: 1993 -2004)
Only 30% respond to 1st line of treatment
About 30% are non-responders (especially psychotic depression)
Failure to respond increases with each episode
How can the signs and symptoms of depression be classified ?
Which particular symptoms fall within each category ?
Psychological/Emotional - Depressed mood, misery, pessimism - Anhedonia - Low self-esteem, guilt, inadequacy - Poor concentration - Indecisiveness and lack of motivation - Feeling of ‘hopelessness’ and ‘helplessness’ - Suicidal thoughts - Hypochondria Somatic/Biological/Psychomotor - Retardation of thought and action – cognitive deficits - Fatigue - Loss of appetite (unintentional weight change) and sleep - disturbance - Aches and pains - Loss of libido Behavioural - Psychomotor agitation or retardation - Self-neglect
What are the 2 types of depressive syndromes ?
Unipolar and bipolar.
What are the 2 types of unipolar depression ?
What is the proportion of each ?
Reactive, non-familial —> association with stressful life-events/anxiety/agitation (75%)
Endogenous - familial pattern –> distinct symptomatology unrelated to stress (25%)
What is bipolar depression ?
Depression alternating with Mania over periods of weeks
Mania component – excessive exuberance/enthusiasm/ self-confidence coupled with impulsivity and occasionally combined with irritability/impatience/aggression.
In extreme cases, psychotic symptoms appear.
Early adult presence, strong hereditary tendency.
What differentiates bipolar depression type 1 and BP type 2 ?
BP1 – mania
BP2 – hypomania
What is the evidence supporting the monoamine hypothesis of depression (“antidepression”) ?
Reserpine depletes MAs : caused depression in some (c. 15%) patients
Iproniazid prevents MA metabolism: caused euphoria
Is the MA hypothesis of depression more useful in understanding the cause or the attenuation of depression (anti-depression) ?
Equivocal evidence for MA hypothesis in the aetiology of depression
Supportive evidence for MA hypothesis in palliation of depression –> Anti-Depression
According to the MA hypothesis of depression, what NT levels must be manipulated to attenuate symptoms ?
Augmentation of NA and 5-HT levels.
What are the symptoms of unipolar depression ?
With which kind of drugs can these be treated ?
Symptoms : Depressed Mood + Inhibited Psychomotor Drive
Thymoleptics = Drugs with pronounced property of re-elevating mood e.g. MA reuptake –TCAs
Thymeretics = Drugs that predominantly activate
psychomotor drive e.g. MA metabolism – MAOIs
Effective Therapeutics should have both.
Why is it dangerous to prescribe drugs that only increase psycho-motor (in the absence of mood elevation e.g. amphetamine) drive to a patient with unipolar depression ?
It increase suicide risk.
What are the main classes of anti-depressant treatments ?
Inhibitors of 5HT and NA Metabolism (MAOIs)
Inhibitors of 5HT and NA Transport (Reuptake Inhibitors)
- TCAs : block reuptake (mainly NA, in vivo)
- SSRIs
- NRIs
- 5-HT and NA Reuptake Inhibitors = SNRIs
Mixed action
- Blockade of inhibitory presynaptic receptors to increase release of NA and 5HT.
- Inhibition of 5HT and NA reuptake combined with blockade of postsynaptic receptors.
Drugs targeting intracellular messengers e.g. rolipram
(phosphodiesterase inhibitor)
Electroconvulsive therapy
How were the effects of MAOs first discovered ?
What is the effect of MAOs (e.g. iproniazid) on the nerve terminal and on the treatment of depression ?
Discovered: Anti-tuberculotic drug Iproniazid –> caused euphoria
Inhibition of nerve terminal MAO-A
Increase in cytoplasmic [5-HT] and [NA]
Efflux of NT via the reuptake transporter (not exocytotic release)
Increase of external [5-HT] and [NA] antidepressant effect especially for ‘Agitated depression’ (depression with anxiety)
What are the substrates for MAO-A Vs MAO-B ?
MAO-A : NA + 5-HT
MAO-B : phenylethylamine + benzylamine
Non-selective : tyramine, DA
Name reversible and irreversible inhibitors of MAO-A.
Irreversible : - Clogyline Reversible (RIMAs) : - Moclobemide - Brofaromine - Pirlindole - Toloxatone - Befloxatone
Name irreversible inhibitors of MAO-B.
Are these drugs used as anti-depressants ?
- Deprenyl/Selegiline
- Pargyline
No, these drugs are used to treat PD.
Name 4 non-selective irreversible MAO inhibitors.
Iproniazid
Isocarboxazid
Phenelzine
Tranylcypromine