Anxiety and Generalised Anxiety Disorder (GAD)

Introduction

Anxiety is a normal physiological response to potential threat or danger. It helps us to improve our performance (e.g. when preparing for exams!). It becomes a problem when it affects our ability to perform.

The Yerkes-Dodson curve describes this relationship.

It is a bell shaped curve, with anxiety on the x-axis and performance on the y-axis.

• As anxiety increases, so does performance – up to a point
• The ideal place to be is left of the peak of the curve – because at this point, anxiety is helping to improve your performance

At the peak, or to the right of the peak, excess anxiety is causing decreased performance, and any additional stress worsens the situation

Physiologic reactions to anxiety

• Decreased blood flow to gut
• Smooth muscle contraction in the gut
• Increased blood flow to skeletal muscle
• Increased muscle tension
• Pupil dilatation
• Nausea
• Increased HR
• Increased BP

Explaining these symptoms to patients suffering from anxiety can be comforting – this can help them to make sense of the strange physical symptoms they feel in response to stressors. Providing this education to patients (and any education about psychiatric illness to patients and their families) is known as psychoeducation. 

Epidemiology and Aetiology

Applies to all anxiety disorders in general

• Affects about 15% of the population
• Commonly associated with depression
• Specific phobia is the most common anxiety disorder
  • 20% of women affected
  • 10% of men affected
• PTSD is the next most common anxiety related disorder
• There are many specific types of diagnosable anxiety. Some others include:
  • Generalised anxiety disorder
  • Separation anxiety disorder
  • Social anxiety disorder
  • Panic attacks
  • Agoraphobia
• Other related conditions (not specifically sub-types of anxiety) include:
  • Obsessive compulsive disorder
  • Body dysmorphia disorder
  • Adjustment disorder
  • Somatic symptom disorder

Generalised Anxiety Disorder

Generalised Anxiety Disorder is a common presentation in both primary and secondary care. It is often associated with depression, and can be chronic (often life long) or associated with certain acute life stresses.

It exists when there is excessive anxiety which is not related to a specific event. 

Diagnosis is made on the basis of history, and there are six key features. Diagnosis requires at least three of these to be present:

• Restlessness
• Fatigue
• Irritability
• Poor concentration
• Sleep disturbance
• Muscle tension

Consider the severity of the presentation by assessing the impact on the patients daily functioning. Are they still going to work? Are they physically taking care of themselves (showing, eating etc).

It is particularly important to consider hyerpthyroidism as the cause of symptoms, and to assess the patient for any co-existing depression.

Epidemiology

• Very common. Prevalence:
  • Men – 2-4%
  • Women 3-4.5%
• Accounts for 1/3 of all psychiatric diagnoses
• Accounts for 10% of all GP consultations
• Closely related to depression – and many patients move between the two states. Often patients satisfy the criteria for both anxiety and depression
  • Shares recognised genetic variables with depression
  • Shares similar underlying neurochemistry to depression
• Episodes tend to have relatively short duration

Aetiology

• Many factors similar to depression – Similar genetic factors to depression
• Stressful live events – likely to be perceived as a ‘threat’, whereas in depression likely to be perceived as a ‘loss’
• In general practice, often anxiety results from a perceived threat to the individuals own health.
• Lack of confiding relationships, small social circle

Clinical features

• Persistent anxiety that is out of proportion to actual events or circumstances. It is usually difficult to control, and leads to reduced and altered functioning. Typically, the worrying will involve everyday matters, e.g. work, money, family etc.
• Apprehension – always feeling on edge
• Motor tension – muscle stiffness, tension headaches, inability to relax, tremor, muscular aches, restless, shakes
• Increased sympathetic activity – Tachycardia, sweating, mydriasis (excessive dilation of the pupils), dizziness, paraesthesia, hot and cold spells, frequent micturition, diarrhoea, nausea, dry mouth
• Hypervigilance – irritability, insomnia, trouble sleeping (can’t get to sleep, only sleeps for short periods), poor concentration
• Panic attacks
  • A single panic attack is not diagnostic of an underlying anxiety disorder
  • 40% of young people will have at least one panic attack
  • Be wary of panic attacks causing physical danger – e.g. causing a person to flee a situation and run across a busy road
• May present with somatisation of a single symptom. For example, they may feel a slight palpitation one day, and become anxious about it. Every time they think they feel it, their anxiety grows. The anxiety fuels the symptom, and vice-versa.

Pathology

• Increased levels of arousal
• Increased sympathetic activity – Tachycardia, sweating, mydriasis (excessive dilation of the pupils).
• Fear, apprehension, and other unpleasant emotions

Differentials

• Depression
• OCD – anxiety forms part of this condition
• Can include any psychotic illness
• Physical symptoms of anxiety may be mimicked by:
  • Hyperthyroidism
  • Alcohol / drug abuse
  • Drug withdrawal
  • Episodes of hypoglycaemia
    • Diet related
    • Diabetes treatment related
  • Tachyarrythmias – e.g. SVT
  • Vitamin B12 deficiency
  • Heavy metal toxicity
  • Phaeochromocytoma – caused by a tumour of the medulla and adrenal glands, results in the secretion of excessive amounts of catecholamines (adrenaline and nnoradrenaline). VERY RARE! Causes many of the symptoms of anxiety associated with excessive sympathetic activity.
• It is not necessary to perform specific tests for phaeochromocytoma or hyperthyroidism in all cases – only if the history is particularly suggestive.

Treatment

• Psychoeducation – explain the diagnosis. Reassure that the physical symptoms are not a sign of any underlying physical problem.
• Avoid exacerbating lifestyle factors
  • Caffeine
  • Nicotine
• Advise regular exercise
  • 150 minutes of moderate intensity exercise per week – equivalent to a brisk walk
  • e.g. 30mins x 5 days per week
• Stress reduction techniques
  • Breathing techniques (see below)
  • Yoga
  • Mindfulness
    • Some good apps can help direct this – such as smiling mind (free) or headspace (subscription required)
  • Get enough sleep
  • Learn to meditate
  • Listen to music
  • Make time for things that you enjoy
  • Consider getting a pet
• Encourage close interpersonal relationships with trusted family and friends
• Cognitive behavioural therapy (see below)
• Pharmacological therapy

Breathing techniques

• Breathe through nose
• Slow, timed, inspiration
• Rebreathing into a paper bag is NOT usually recommended
• Hyperventilation syndrome secondary to anxiety can occur with prolonged hyperventilation. It causes:
  • Dizziness and / or syncope
  • Palpitations
  • Sweating
  • Dry mouth
  • Agitation
  • Fatigue
  • Carpopedal spasm – involuntary muscle contractions in the hands and feet. This occurs as a result of cascade of equilibrium which occurs secondary to the low CO2 levels seen in hyperventilation. Low CO2 results in alkalaosis. This is neutralised by H+ from plasma proteins. The excess protein anions that result then take up calcium, and calcium levels are depleted, resulted in hypocalcaemic tetany.

Symptoms soon resolve with slowed, regular breathing

Cognitive behavioural therapy

• CBT aims to arm a patient with techniques and thought processes to address negative thought patterns and behaviour
• In anxiety, this often involves a thorough discussion of fears and triggers, rational explanation and finally replacement of these negative fearful thoughts with positive ones
• Can be carried out by an appropriately trained practitioner – which could be a doctor, a psychologist or a psychiatrist
  • Consider early referral to psychologist if you are not trained yourself
• Can also be self-directed online or via an app. Some studies have shown that this is as effective as face to face CBT. Useful resources include:
  • Headspace (NHS app – subscription required)
  • The black dog Institute – MyCompass programme (on black dog institute website – free)
  • Mood Gym (website – free)
  • E-Couch (website – free)

Pharmacological therapy

Not always considered first line, except in severe cases. In most cases, is reserved for patients that have failed to respond to the basic principles +/- CBT as outlined above. It is often most useful in those with co-existing depression who may lack the motivation for the self-directed approach required by many of the basic techniques.

• Drugs that reduce anxiety are known as anxiolytics
• GABA is the main inhibitory neurotransmitter found in these systems
• SSRIs have proven benefit – but are not as effective as CBT in generalised anxiety disorder
• In panic attack disorder they can reduce the number of panic attacks by 60-90%
  • Treat for minimum of 6 months
  • Assess effectiveness at 12 weeks (this is typically longer than the 6-8 weeks recommended for depression)
  • Not all SSRIs are approved for anxiety
  • There is not enough evidence to effectively determine which SSRIs are most effective for anxiety. However, duloxetine and venlafaxine are most commonly recommended
• Propranolol
  • Useful for situational anxiety to control physiological symptoms – e.g. public speaking / doing presentations work
  • Has no direct pharmacological effect on the underlying psychological causes of these symptoms, although reducing the physical symptoms can help to reduce the anxiety
• Benzodiazepines
  • These bind to receptors and increase the amount of GABA released. There are other agents that bind to the same receptors, but have the opposite effect, and cause a decrease in GABA release, which could exacerbate an anxiety state.
  • e.g. diazepam (“Valium”(R)), temazepam, lorazepam
  • Should be used with caution
  • Short-term or infrequent use only
    • Were used frequently in the past, but often lead to addiction and escalating doses
  • Many reasons to avoid use:
    • Risk of addiction in regular long-term use
    • Oversedation, impaired level of consciousness
    • Adverse effect on mood
    • Interaction with alcohol
    • Sexual dysfunction
    • Reduced motivation
  • Useful for specific phobias
  • NOT recommended in panic attack disorder
    • Often not quick enough onset – attack has often resolved by the time they start to work
• Quetiapine
  • An atypical anti-psychotic, commonly used in schizophrenia (psychosis) and sedation of the elderly in dementia
  • In Australia, it is licensed for anxiety, but not subsided by the PBS for this indication
  • Doses used are typically very small compared to those used for psychosis
  • Can cause long-QT syndrome
  • May precipitate confusion in elderly patients
  • Useful for panic attacks and in insomnia
  • Use very small doses e.g. 12.5mg PRN
  • A strong sedative effect
  • Not addictive
  • In my own personal practice, I often use it in place of benzodiazepines to control acute severe anxiety, anxiety with insomnia and panic attacks. I usually prescribe a short course of 12.5mg at night (or PRN in panic attacks) for several weeks whilst the SSRI takes time to have an effect. I always recommend it alongside the lifestyle and CBT advice given above

Other interventions

• Reassure the patient it is a common condition, that does not indicate serious disease
• Advise that relaxation classes, yoga, and meditation are often helpful for many patients.
• Perhaps discuss underlying problems (the perceived ‘threats’) with the patient. The GP will have to decide if the patient needs to see him, or other professionals again to discuss and help with these underlying issues. This often may not be health care professionals, but other professionals, perhaps those involved with social care, or the Citizen’s Advice bureau for example.

Management of a panic attack

• Sit down, try to relax
• Control the breathing rate. Count to 4 between breathing in and breathing out. Take slow deep breaths.
• Paper bag breathing is controversial. If hyperventilation is truly involved, then it may be helpful at controlling oxygen and carbon dioxide levels, but otherwise, it can lead to hypoxia and hypercapnia, which inturn can exacerbate the situation.
• Medication can be useful in some patients. Benzodiazepines are widely used in acute anxiety attacks

Prognosis

• Most acute cases remit
• BUT – recurrence is common
• Many patients with a chronic anxiety state have social problems that need to be resolved with appropriate social interventions
• Many patients with chronic symptoms will eventually develop depression as well

Other types of anxiety disorder

Other types of anxiety disorder are considered separately, the article on Fear, phobia and Panic disorders

Differentiating types of anxiety disorder

A good history can help to differentiate the type of anxiety disorder present. Often there is overlap and multiple disorders may be present

References

• Murtagh’s General Practice. 6th Ed. (2015) John Murtagh, Jill Rosenblatt
• Oxford Handbook of General Practice. 3rd Ed. (2010) Simon, C., Everitt, H., van Drop, F.
• Beers, MH., Porter RS., Jones, TV., Kaplan JL., Berkwits, M. The Merck Manual of Diagnosis and Therapy

Read more about our sources

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