The success of behavioural therapy for anxiety disorders is typically measured through a combination of subjective and objective methods. Subjectively, patients are often asked to report changes in their feelings of anxiety, fear, and overall well-being throughout the course of the therapy. This can be done through self-report scales, like the Fear Survey Schedule or the Beck Anxiety Inventory, where patients rate their symptoms. Objectively, therapists might observe and record the patient's responses during therapy sessions, noting changes in physical symptoms of anxiety (such as heart rate or sweating) and behavioural responses to exposure tasks. Additionally, the achievement of specific treatment goals, like facing a particular feared situation without excessive anxiety, is a crucial measure of success. In some cases, feedback from family members or others close to the patient can also be considered to gauge improvements in the patient's everyday life. A combination of these assessment methods provides a comprehensive picture of the therapy's effectiveness.

Relaxation techniques are a fundamental component of systematic desensitisation, serving to counteract the anxiety response during exposure to feared stimuli. These techniques help in activating the body's natural relaxation response, a state of rest that counterbalances the fight or flight response triggered by fear and anxiety. They include deep breathing exercises, progressive muscle relaxation, guided imagery, and mindfulness meditation. During the therapy, patients are first taught these techniques in a calm and controlled environment. The therapist guides the patient through exercises that focus on relaxing different muscle groups and controlling breathing. This training helps patients in recognising and controlling their physical responses to anxiety. As therapy progresses, these relaxation techniques are employed during exposure to the feared object or situation. By practicing relaxation in the face of fear, patients gradually learn to dissociate the feared stimuli from the anxiety response, effectively reducing their phobic reaction over time. This not only helps during therapy sessions but also equips patients with skills they can use in real-life situations outside of therapy.

When using behavioural therapy for treating children with anxiety disorders, several ethical considerations must be addressed. Firstly, informed consent is essential. For children, this means obtaining consent from parents or guardians, as well as assent from the child, ensuring they understand the therapy and are comfortable with it. Secondly, the therapy must be age-appropriate and sensitive to the developmental stage of the child. Techniques and materials used should be suitable for the child's cognitive and emotional maturity level. Thirdly, ensuring the child's safety and well-being throughout the therapy process is paramount. The therapy should not induce excessive distress or fear. Additionally, confidentiality must be maintained, while also ensuring that parents or guardians are adequately informed about the child's progress and any issues that arise. Finally, therapists must be vigilant about the power dynamics in therapist-child relationships and maintain a supportive, respectful, and non-coercive environment. Ethical practice in treating children not only involves adherence to these principles but also requires therapists to stay updated with the latest research and guidelines pertaining to child psychology and therapy.

Behavioural therapy can be effectively combined with other treatment methods for anxiety disorders, creating a more comprehensive approach. This is known as a multimodal treatment strategy. For instance, combining behavioural therapy with cognitive therapy forms Cognitive-Behavioural Therapy (CBT), which addresses both the behavioural and cognitive patterns contributing to the anxiety disorder. CBT is particularly effective because it not only helps patients to manage their fear response through behavioural techniques like systematic desensitisation but also helps in altering negative thought patterns associated with the anxiety. Furthermore, in some cases, behavioural therapy is combined with pharmacotherapy, especially in severe anxiety disorders. Medications like SSRIs (Selective Serotonin Reuptake Inhibitors) can reduce overall anxiety levels, making it easier for patients to engage in behavioural therapy. However, the choice to combine therapies should be based on individual patient needs, the severity of the disorder, and the specific type of anxiety disorder being treated. A tailored approach, often decided upon by a mental health professional, ensures that patients receive the most effective and personalised treatment.

Systematic desensitisation is a specific type of exposure therapy designed to reduce fear and anxiety responses. It differs from other exposure therapies in its structured and gradual approach. Unlike other methods, such as flooding, which involves immediate and intense exposure to the feared object or situation, systematic desensitisation progresses gradually. It begins with teaching relaxation techniques to the patient, which are then employed during the exposure process. This gradual exposure starts from the least frightening scenario, based on an anxiety hierarchy created by the patient, and moves progressively to more challenging situations. This methodical progression allows the patient to develop coping skills and confidence at each level before advancing, minimising the risk of overwhelming anxiety. Additionally, systematic desensitisation often incorporates imaginary exposure before moving to real-life scenarios, allowing for a more controlled and patient-friendly approach. This distinction makes systematic desensitisation particularly suitable for individuals with intense phobias who might not tolerate immediate full exposure.