Diagnosis of Generalised Anxiety Disorder
The diagnosis of generalised anxiety disorder is made through a comprehensive clinical assessment by a qualified mental health professional, GP, or psychiatrist. Generalised anxiety disorder is diagnosed when a person experiences persistent and excessive worry about various aspects of life on most days for at least six months, and this worry causes significant distress or functional impairment.
Because anxiety is a natural and sometimes even helpful emotional response, distinguishing between normal worry and an anxiety disorder requires attention to duration, intensity, impact, and context. The key is whether the anxiety is disproportionate, chronic, and difficult to control.
Diagnostic Criteria
According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), the diagnostic criteria for GAD include:
Excessive anxiety and worry (apprehensive expectation), occurring more days than not for at least six months, about a number of events or activities (such as work performance, finances, or health)
The person finds it difficult to control the worry
The anxiety and worry are associated with three or more of the following six symptoms (with at least some symptoms present more days than not for the past six months):
Restlessness or feeling on edge
Being easily fatigued
Difficulty concentrating or mind going blank
Irritability
Muscle tension
Sleep disturbance (difficulty falling or staying asleep, or restless, unsatisfying sleep)
For children and adolescents, only one of these six symptoms is required for a diagnosis.
The anxiety must cause clinically significant distress or impairment in social, occupational, or other important areas of functioning, and must not be attributable to substance use, medical conditions, or another mental disorder (such as panic disorder or PTSD).
Clinical Interview
The diagnostic process begins with a detailed interview. The healthcare provider will ask about:
The nature and focus of the worries
How long the anxiety has been present
Physical symptoms and how they affect daily life
Family history of anxiety or other mental health issues
Any coexisting conditions, such as depression, substance use, or trauma
Patients may not always recognise that their level of worry is excessive, so input from family members or carers can sometimes be helpful, especially in paediatric cases.
Screening Tools
While diagnosis is primarily based on clinical judgement, validated screening tools can support the assessment. These may include:
GAD-7 (Generalised Anxiety Disorder 7-item scale) – a self-reported questionnaire used to assess the severity of symptoms
Hamilton Anxiety Rating Scale (HAM-A) – a clinician-administered measure of anxiety levels
Beck Anxiety Inventory (BAI) – commonly used to measure physiological and cognitive aspects of anxiety
These tools help monitor progress and response to treatment over time, though they are not a substitute for formal diagnosis.
Ruling Out Medical Conditions
Several physical conditions can mimic or worsen anxiety, so healthcare providers often perform:
Physical examination
Blood tests (to check thyroid function, vitamin B12, or anaemia)
Cardiovascular assessments, if palpitations or chest pain are present
Conditions like hyperthyroidism, perimenopause, irritable bowel syndrome (IBS), and cardiac arrhythmias may produce similar symptoms.
Coexisting Disorders
It’s also important to assess for other mental health disorders, such as:
Depression
Panic disorder
OCD
PTSD
ADHD
Social anxiety disorder
These conditions often overlap with GAD, and treatment plans must be adapted accordingly.
Diagnosis of Generalised Anxiety Disorder
An accurate diagnosis of generalised anxiety disorder is essential to help individuals access appropriate support, understand their symptoms, and start a treatment journey that restores peace of mind and daily functioning.
