Managing anxiety disorders in adults

Anxiety disorders, like all mental disorders, lie on a spectrum that extends from normal anxiety to transient symptoms, through to severe and disabling symptoms that can persist for years. The specific thoughts and behaviours that characterise each of the anxiety disorders are covered in the RANZCP Clinical Practice Guidelines for anxiety disorder.¹ These disorders include variants of excessive worry, acute attacks of anxiety or panic and avoidance of anxiety-provoking situations. 

Panic disorder, social anxiety disorder (SAD) and generalised anxiety disorder (GAD) are the most common anxiety disorders in Australia and New Zealand. Obsessive compulsive disorder (OCD) and post-traumatic stress disorder (PTSD) have been moved out of the DSM-5 chapter on anxiety disorders and placed in their own categories of ‘Obsessive compulsive and related disorders’, and ‘Trauma and stressor-related disorders’, respectively. 

The systematic implementation of ­anxiety disorder guidelines has been shown to result in earlier treatment gains and shorter treatment times.² This article draws from the RANZCP guidelines to focus on the use of psychological treatments and pharmacotherapy to treat panic disorder, SAD and GAD, for which there is considerable evidence of efficacy. The key features of these anxiety disorders are presented in Table 1. This article also ­provides practical clinical guidance on cognitive behavioural therapy (CBT) as the principal psychological treatment for the anxiety disorders as it has the most extensive evidence base for its efficacy. Furthermore, it is available online, allowing easy and extensive dissemination. The selective serotonin reuptake inhibitor (SSRI) and serotonin and noradrenaline reuptake inhibitor (SNRI) antidepressants are also covered because the evidence base of ­benefit is larger, the side effect profile is better, and the experience of practitioners is wider than with other classes of medica­tion, especially the older, or first generation, antidepressants. 

Factors contributing to the onset of anxiety disorders

Anxiety disorders arise from a combination of vulnerable personality traits, early life stressors and psychosocial adversity (for example, lack of support, hardship, dysfunctional relationships) and are often triggered by stressful significant life events (such as the death of a loved one, an illness, childbirth or workplace bullying). Temperamental traits, with a moderate level of heritability (such as neuroticism or negative emotionality), are important vulnerability factors for anxiety; neuroticism, in particular, seems to confer greater vulnerability to how an individual responds to psychological distress, which may precipitate an ­anxiety disorder in the context of environmental or interpersonal stressors.

Substance use and misuse (including over-the-counter medications, herbal medications and intoxication) or withdrawal are often missed as a cause of anxiety, hence it is important to screen for these. 

Prevalence, cost and functional impact

Anxiety disorders, as conceptualised in ­previous classification systems such as DSM-IV (that included OCD and PTSD as anxiety disorders), form the most ­common class of mental disorders.^3-6 The second ­Australian Survey of Mental Health and Wellbeing, based on the DSM-IV, ­estimated that one in seven adults (14.4% of the population) experienced an anxiety disorder in the past 12 months. A very similar rate (14.8%) was estimated in New Zealand.^7,8 SAD is the most prevalent anxiety disorder, followed by GAD and panic disorder/agoraphobia (Table 2).^8,9 Anxiety disorders are more common in women than men; in people who are separated, divorced or widowed; and those who are less educated or unemployed. Demographic status may be both a consequence and a cause of anxiety disorders.¹⁰ 

Anxiety disorders are associated with high levels of distress, disability and service use.¹⁰ In the second Australian Survey of Mental Health and Wellbeing, in people who met criteria for an anxiety disorder, about half reported an inability to work or do normal tasks for less than one day during the previous month because of anxiety, a third reported one to seven days and one-sixth reported more than seven days. 

Onset and course

Anxiety disorders typically start early in life (Table 3), and prevalence declines with age.^7,11 Developing an anxiety disorder after the age of 40 years is uncommon, and so when a person over 40 presents with an initial onset of an anxiety disorder, alternative causes of anxiety such as mood disorders, alcohol and substance use ­disorders, trauma, physical illness or its treatment should be considered.^9,10

Panic disorder often follows a waxing and waning course with periods of increased anxiety (characterised by worsening or episodic flares of symptoms) and periods of remission in between. Some experience a fluctuating course with exacerbations that are often precipitated by life-event stress, excess caffeine, sleep disruption, physical illness or hormonal changes, whereas others have a more chronic course. Only a minority have complete, sustained remission without relapse.^12-14