The Nurse′s Guide to Mental Health Medicines

Elizabeth J. Holland

• Publisher: SAGE Publications Ltd
• Year: 2018
• ISBN:
  9781526450340
• Edition: 1
• Topic: Medicina
• Subtopic: Psichiatria e salute mentale

The Nurse?s Guide to Mental Health Medicines is an invaluable, pocket sized guide to a complex subject.Each chapter provides a short and easy-to-read overview of the different drug types used in mental health nursing, focusses only on the need to know information and the associated risks and side effects. The chapters also provide a short medicines list that gives you fast facts relating to the most common drugs used in practice. Key features:

• Simple layout with clear tables putting the facts at your fingertips
• Written by nurses for nurses providing the perfect amount of detail for the busy student or practitioner
• Clear and simple language combined with real world case studies to cut through the jargon and terminology

1 Antidepressant Medications

Liz Holland

After reading this chapter, you will be able to:

• Consider the needs of individuals who may take antidepressant medication.
• Have a basic awareness of how antidepressant medications came about.
• Hold a basic understanding of the different types of antidepressant medications and how they work.
• Consider the risks and benefits of different types of antidepressant medications.
• Apply basic knowledge around antidepressant medications to clinical decision-making.

When do we need antidepressant medications?

Since the 1980s, depression has been referred to as the ‘common cold’ of mental illness (Rottmann, 1986) due to its high prevalence rate. Many people in the UK has been affected by depression in some way, whether it be because they have lived the experience of depression themselves or because they have seen a friend or family member battle an episode of depression. Around 20 per cent of adults in the UK reported clinical symptoms of depression in 2015 (ONS, 2015).

Depression is a mood disorder, and is characterised by symptoms such as: feelings of helplessness and hopelessness, a loss of interest in daily activities and a feeling of having no energy, disruption to sleep and appetite, having difficulties in being able to concentrate, negative thinking and having thoughts of guilt and worthlessness.

Living with depression can be incredibly debilitating for people, and the following blog entry demonstrates the daily struggles that people living with depression can face …

Stepped into the black hole. i don’t know why. i don’t know

when. this was not on the schedule. i was not prepared.

heavy. hurts to stand. hurts to sit. breathing takes all the

energy i’ve got. nothing poetic or dramatic to say. can’t

breathe. can’t think. brain is not my own. thoughts of

nonsense. focus – i have none. never will be able to explain

the whole-body experience of crippling depression. never. i

can feel the hole in the middle of my chest …’

(Etta 2008, published in Kotliar 2016: 1206).

In severe cases of depression, sufferers can experience thoughts of suicidality; some individuals may feel that they need to act on these, and approximately 15 per cent of people with depression go on to die from suicide (Jiaquan Xu et al., 2016).

The causes of depression are still not fully understood. However, there is a generally accepted argument that there is some level of biological influence, although this is in conjunction with other psychological and sociological factors.

The biological explanation of depression is based on the role of three neurotransmitters in the brain: serotonin, dopamine and norepinephrine. Neurotransmitters are chemical messengers for the brain; they help different areas of the brain communicate with one another. Serotonin, dopamine and norepinephrine are particularly important in the areas of mood, sexual desire and sexual function, sleep, memory, appetite and social behaviour. Therefore, it makes sense that, as these are the areas in which people experience difficulties when they have an episode of depression, then the neurotransmitters linked to them may also be involved in the depression. However, the biological explanation proposed for depression was only suggested after the invention of antidepressants, rather than before. Indeed, antidepressants and their effects on mood were initially discovered by accident, and there is still only a very limited understanding of why and how they work. For some people, they just do!

Since the 1950s, when antidepressants first became available on the commercial market, it has been suggested that depression is caused by an imbalance in the levels of these neurotransmitters in the brain, in particular of serotonin (prior to this, stimulant drugs were given to people with depression!). However, there is little scientific evidence to support this. It is currently being suggested that people who are vulnerable to depression have less sensitive serotonin receptors in their brain than those who are not vulnerable to depression (Kring et al., 2013). This means that people who are vulnerable to depression may not be able to produce as much serotonin in their brains, and this goes on to affect their mood and behaviour.

There are four different types of antidepressant medication and, although the mechanisms that enable each of these types to work are slightly different, overall the common theme with all antidepressants is that they enable the levels of serotonin, dopamine and norepinephrine to rise in the brain, and these increased levels seem to lead to an improvement in symptoms for some people. However, it should be noted that this explanation is limited: we know that the increased levels of neurotransmitters in the brain occur merely hours after a dose of an antidepressant medication is ingested, yet, typically, antidepressants take about 2–6 weeks to have a noticeable effect; there is currently no convincing biological explanation for this.

The four different categories of antimedications and the intricacies of how they work will now be discussed.

What are the different types of antidepressant medications and how do they work?

The earliest category of antidepressant medications came onto the commercial market in 1957 (Moncrieff, 2011) and these are known as tricyclic antidepressants. You may recognise names such as imipramine and amitriptyline, which are the most well-known and well-used drugs of the tricyclic family. Most simply, the tricyclics cause the brain to increase the production of serotonin and norepinephrine, alongside stopping the production of another neurotransmitter known as acetylcholine, which in high levels is known to inhibit serotonin production. However, problems with tricyclic antidepressants were quickly identified: they had serious toxic effects on the cardiac systems of some individuals, and were also highly toxic if they were taken even in small amounts in overdose situations, which is not ideal when they are being prescribed for a client group who may be experiencing thoughts of ending their life.

Monoamine oxidase inhibitor (MAOI) antidepressants were the next type of antidepressant to arrive. They were developed because they had less severe side effects than those of the tricyclics, and were also noted to be very good at treating feelings of anxiety as well as the symptoms of depression. MAOIs work by preventing the breakdown of serotonin and norepinephrine in the brain, thus leading to increased levels of these neurotransmitters within the brain. The most concerning side effect of MAOIs is their impact on blood pressure: they are linked to the development of postural hypotension, particularly in older people. Something important to note is that people on MAOI antidepressants must follow a strict diet and avoid any food or drink products that contain tyramine (see Fact Box 1.1). If tyramine is consumed by someone who is taking an MAOI, it can cause a severe headache and a sudden increase in blood pressure, known as a hypertensive crisis. Over-the-counter medicines that can be used to treat coughs and colds can also cause sudden hypertensive crisis in people who are taking MAOIs so it is important to talk to a doctor, nurse or pharmacist before such medication is taken.

Today, MAOIs and tricyclics are less likely to be used than the selective serotonin reuptake inhibitor (SSRI) antidepressants (below) as they have more severe side effects. They are more often used in older people, or in people with depression that have not responded to SSRI medication.

Fact Box 1.1 What sorts of foods contain tyramine?

• Cheese
• Alcohol and non-alcoholic beer
• Gravy
• Salami, pepperoni and other cured meats
• Marmite
• Yoghurt
• Oxo
• Bovril
• Liver
• Chocolate
• Foods that are beginning to go off

SSRIs and serotonin and norepinephrine reuptake inhibitors (SNRIs) are the final two types of antidepressants and are the most modern. In general, they are noted to have less side effects than the older tricyclics and MAOIs.

SSRIs are medicines that work specifically on the neurotransmitter, serotonin. They prevent the reuptake of serotonin within the brain, which allows levels of serotonin to build up. SSRIs are the most common type of antidepressant used, and tend to be the first-line medicinal intervention.

SNRIs are the newest type of antidepressant available. They work by preventing the reuptake of bot...