Skip to main content
Home > Professional > Problems > Anxiety

Anxiety

Fear and its associated reactions (freeze, flight, fight) can be useful responses to a dangerous or threatening situation. However, clients suffering from anxiety disorders experience these reactions too strongly, too often, or in inappropriate situations - and they can be distressing and exhausting. Psychology Tools can help you with CBT for anxiety - our anxiety worksheets are designed to help clients with generalized anxiety disorder (GAD), health anxiety (hypochondriasis), panic disorder, phobias, and social anxiety. Read more
languages 54 languages

Filter

Problem

Therapy tool

Language

Decatastrophizing

Catastrophic thinking (magnification) is characteristic of many anxiety problems. This CBT worksheet for decatastrophizing is a tool for cognitive res ... https://www.psychologytools.com/resource/decatastrophizing/

Exercise

Embracing Uncertainty

Intolerance of uncertainty (IU) was first described in individuals suffering from Generalized Anxiety Disorder (GAD). Many behaviors associated with G ... https://www.psychologytools.com/resource/embracing-uncertainty/

Exercise

Worry Postponement

Worry postponement is often prescribed as an exploratory or standalone intervention relatively early in the treatment of GAD, but ‘worry postponeme ... https://www.psychologytools.com/resource/worry-postponement/

Exercise

A Guide To Emotions (Psychology Tools For Living Well)

Cognitive behavioral therapy can help your clients to live happier and more fulfilling lives. Psychology Tools for Living Well is a self-help course ... https://www.psychologytools.com/resource/a-guide-to-emotions-psychology-tools-for-living-well/

Chapter

Anxiety Self-Monitoring Record

Self-monitoring is a fundamental tool in cognitive behavioral therapy (CBT). This Anxiety Self-Monitoring Record is designed to help clients to bette ... https://www.psychologytools.com/resource/anxiety-self-monitoring-record/

Worksheet

Approach Instead Of Avoiding (Psychology Tools For Overcoming Panic)

Psychology Tools for Overcoming Panic takes a cognitive behavioral therapy (CBT) approach to this common anxiety problem. This chapter discusses avoi ... https://www.psychologytools.com/resource/approach-instead-of-avoiding-psychology-tools-for-overcoming-panic/

Chapter

Assertive Communication

Communicating assertively is an essential skill for maintaining healthy self-esteem and strong relationships. This information handout describes the k ... https://www.psychologytools.com/resource/assertive-communication/

Information Handout

Assertive Responses

Communicating assertively is an essential skill for maintaining healthy self-esteem and strong relationships. The Assertive Responses exercise helps c ... https://www.psychologytools.com/resource/assertive-responses/

Exercise

Autonomic Nervous System

The autonomic nervous system (ANS) automatically regulates the function of body systems outside of voluntary control. The Autonomic Nervous System han ... https://www.psychologytools.com/resource/autonomic-nervous-system/

Information Handout

Avoidance Hierarchy

Avoidance and safety-seeking behavior serves to maintain anxiety, and exposure to the fear stimuli/situation is an effective treatment for anxiety. Th ... https://www.psychologytools.com/resource/avoidance-hierarchy/

Exercise

Behavioral Experiment

Behavioral experiments are planned experiential activities to test the validity of a belief. They are one of the most powerful techniques available to ... https://www.psychologytools.com/resource/behavioral-experiment/

Worksheet

Behavioral Experiment (Portrait Format)

Behavioral experiments allow individuals to test the validity of their beliefs and assumptions. They are a core experiential technique for therapeutic ... https://www.psychologytools.com/resource/behavioral-experiment-portrait-format/

Worksheet

Behaviors In Panic (Psychology Tools For Overcoming Panic)

Psychology Tools for Overcoming Panic takes a cognitive behavioral therapy (CBT) approach to this common anxiety problem. This chapter discusses beha ... https://www.psychologytools.com/resource/behaviors-in-panic-psychology-tools-for-overcoming-panic/

Chapter

Body Sensations In Panic (Psychology Tools For Overcoming Panic)

Psychology Tools for Overcoming Panic takes a cognitive behavioral therapy (CBT) approach to this common anxiety problem. This chapter discusses body ... https://www.psychologytools.com/resource/body-sensations-in-panic-psychology-tools-for-overcoming-panic/

Chapter

Breathing To Calm The Body Sensations Of Panic (Psychology Tools For Overcoming Panic)

Psychology Tools for Overcoming Panic takes a cognitive behavioral therapy (CBT) approach to this common anxiety problem. This chapter discusses the ... https://www.psychologytools.com/resource/breathing-to-calm-the-body-sensations-of-panic-psychology-tools-for-overcoming-panic/

Chapter

CBT Appraisal Model

The CBT Appraisal Model worksheet is a transdiagnostic formulation tool. The centrality of appraisals underpins all of the disorder-specific cognitive ... https://www.psychologytools.com/resource/cbt-appraisal-model/

Worksheet

CBT Thought Record

The CBT Thought Record is an essential tool in cognitive behavioral therapy. Thought challenging records help people to evaluate their negative automa ... https://www.psychologytools.com/resource/cbt-thought-record/

Worksheet

Challenging Your Negative Thinking

Challenging Your Negative Thinking

A cornerstone of cognitive behavioral therapy is that an individual’s interpretation of an event determines how they feel and behave. We all experie ... https://www.psychologytools.com/resource/challenging-your-negative-thinking/

Guide

Classical Conditioning

Classical conditioning is a process by which stimuli become associated with responses. This information handout describes key principles of Classical ... https://www.psychologytools.com/resource/classical-conditioning/

Information Handout

Cognitive Behavioral Model Of Fear Of Bodily Sensations (2018)

Fear of bodily sensations is present in a number of conditions, most notably panic disorder. The Cognitive Behavioral Model Of Fear Of Bodily Sensatio ... https://www.psychologytools.com/resource/cognitive-behavioral-model-of-fear-of-bodily-sensations-2018/

Information Handout

Cognitive Behavioral Model Of Generalized Anxiety Disorder (GAD) (1998)

Individuals with generalized anxiety disorder (GAD) report significant worry which they find difficult to control and experience as distressing. Numer ... https://www.psychologytools.com/resource/cognitive-behavioral-model-of-generalized-anxiety-disorder-gad-1998/

Information Handout

Cognitive Behavioral Model Of Health Anxiety (2003)

Health anxiety is characterized by a preoccupation with having or acquiring a serious illness, and a high level of anxiety about health. People with h ... https://www.psychologytools.com/resource/cognitive-behavioral-model-of-health-anxiety-2003/

Information Handout

Cognitive Behavioral Model Of Health Anxiety (2018)

Health anxiety is characterized by a preoccupation with having or acquiring a serious illness, and a high level of anxiety about health. People with h ... https://www.psychologytools.com/resource/cognitive-behavioral-model-of-health-anxiety-2018/

Information Handout

Cognitive Behavioral Model Of Panic (1986)

The Cognitive Behavioral Model Of Panic identifies catastrophic misinterpretation of body sensations as a criticial maintenance factor which serves to ... https://www.psychologytools.com/resource/cognitive-behavioral-model-of-panic-1986/

Information Handout

Combined Relaxation Exercise

Combined Relaxation Exercise (Audio)

The Combined Relaxation Exercise is an audio track from the Psychology Tools For Relaxation Audio Collection. It is designed to help anyone experienci ... https://www.psychologytools.com/resource/combined-relaxation-exercise-audio/

Audio

Coping With Body Sensations (Psychology Tools For Overcoming Panic)

Psychology Tools for Overcoming Panic takes a cognitive behavioral therapy (CBT) approach to this common anxiety problem. This chapter discusses inte ... https://www.psychologytools.com/resource/coping-with-body-sensations-psychology-tools-for-overcoming-panic/

Chapter

Developing Psychological Flexibility

Developing Psychological Flexibility is a client information handout which can be used to familiarize clients with the ACT model. ... https://www.psychologytools.com/resource/developing-psychological-flexibility/

Information Handout

Emotions In Panic (Psychology Tools For Overcoming Panic)

Psychology Tools for Overcoming Panic takes a cognitive behavioral therapy (CBT) approach to this common anxiety problem. This chapter discusses the ... https://www.psychologytools.com/resource/emotions-in-panic-psychology-tools-for-overcoming-panic/

Chapter

Emotions Motivate Actions

Many clients find it helpful to recognize the range of actions that are motivated by different emotional states. This worksheet encourages clients to ... https://www.psychologytools.com/resource/emotions-motivate-actions/

Information Handout

Exercise For Mental Health

Exercise is an evidence-based treatment for depression and anxiety and research suggests that, in the treatment of depression, exercise interventions ... https://www.psychologytools.com/resource/exercise-for-mental-health/

Information Handout

Exposure Practice Form

Exposure is an effective treatment for many forms of anxiety. The Exposure Practice Form is a CBT worksheet which guides therapists and clients throug ... https://www.psychologytools.com/resource/exposure-practice-form/

Exercise

Facing Your Fears (CYP)

Graded or graduated exposure is a traditional way of overcoming fears and phobias. The therapist helps the client to draw up a list of feared situatio ... https://www.psychologytools.com/resource/facing-your-fears-cyp/

Worksheet

Fight or Flight (CYP)

The Fight Or Flight (CYP) information handout has been specifically designed for younger children and includes carefully simplified language. The full ... https://www.psychologytools.com/resource/fight-or-flight-cyp/

Information Handout

Fight Or Flight Response

The fight or flight response is an automatic physiological reaction to an event that is perceived as stressful or frightening. The perception of threa ... https://www.psychologytools.com/resource/fight-or-flight-response/

Information Handout

Grounding Statements Audio Exercise

Grounding Statements (Audio)

Grounding techniques are used to help people to reorient themselves to the present moment and to safety. Grounding Statements are a form of cognitive ... https://www.psychologytools.com/resource/grounding-statements-audio/

Audio

Grounding Techniques

Individuals who have experienced trama often find it difficult to stay within the ‘window of tolerance’. Grounding techniques (which can b ... https://www.psychologytools.com/resource/grounding-techniques/

Exercise

Habituation

The Habituation information sheets are designed to help clinicians to explain the concept of habituation and its role in exposure therapy. The handout ... https://www.psychologytools.com/resource/habituation/

Information Handout

Health Anxiety Thought Monitoring Record

Individuals with health anxiety experience clinically significant distress associated with health concerns. This thought-monitoring record enables cli ... https://www.psychologytools.com/resource/health-anxiety-thought-monitoring-record/

Worksheet

Health Anxiety Thought Record

Individuals with health anxiety experience clinically significant distress associated with health concerns. This thought-challenging record enables cl ... https://www.psychologytools.com/resource/health-anxiety-thought-record/

Worksheet

How Breathing Affects Feelings

Normal, anxious, and exercise breathing have significant effects upon our physiology and our emotions. This information handout explains the physiolog ... https://www.psychologytools.com/resource/how-breathing-affects-feelings/

Exercise

How Does This All Add Up To A Panic Attack? (Psychology Tools For Overcoming Panic)

Psychology Tools for Overcoming Panic takes a cognitive behavioral therapy (CBT) approach to this common anxiety problem. This chapter discusses the ... https://www.psychologytools.com/resource/how-does-this-all-add-up-to-a-panic-attack-psychology-tools-for-overcoming-panic/

Chapter

How Is Panic Disorder Different From A Panic Attack? (Psychology Tools For Overcoming Panic)

Psychology Tools for Overcoming Panic takes a cognitive behavioral therapy (CBT) approach to this common anxiety problem. This chapter disambiguates ... https://www.psychologytools.com/resource/how-is-panic-disorder-different-from-a-panic-attack-psychology-tools-for-overcoming-panic/

Chapter

How Much Do You Know About Panic? (Psychology Tools For Overcoming Panic)

Psychology Tools for Overcoming Panic takes a cognitive behavioral therapy (CBT) approach to this common anxiety problem. This chapter includes a qui ... https://www.psychologytools.com/resource/how-much-do-you-know-about-panic-psychology-tools-for-overcoming-panic/

Chapter

How Your Body Responds To Stress

Many clients identify with the concept of ‘stress’ more readily than ‘threat’ and the The How Your Body Responds To Stress information handou ... https://www.psychologytools.com/resource/how-your-body-responds-to-stress/

Information Handout

Identifying The Meaning Of Body Sensations

Some anxiety disorders (including panic and health anxiety), are concerned with body sensations and symptoms. The Identifying The Meaning Of Body Sens ... https://www.psychologytools.com/resource/identifying-the-meaning-of-body-sensations/

Worksheet

Interoceptive Exposure

Misappraisals of body sensations trigger emotional and physiological reactions of fear and heightened arousal. These feelings motivate behavioral resp ... https://www.psychologytools.com/resource/interoceptive-exposure/

Exercise

Intolerance Of Uncertainty

Uncertainty is a normal part of life – we can never be 100% sure about what will happen next. Many people feel good about uncertainty and live lives ... https://www.psychologytools.com/resource/intolerance-of-uncertainty/

Information Handout

Introduction To CBT (Psychology Tools For Overcoming Panic)

Psychology Tools for Overcoming Panic takes a cognitive behavioral therapy (CBT) approach to this common anxiety problem. This chapter includes a bri ... https://www.psychologytools.com/resource/introduction-to-cbt-psychology-tools-for-overcoming-panic/

Chapter

Intrusive Memory Record

Intrusive (unwanted, involuntary) memories are a common feature of PTSD, but also depression and other conditions. This Intrusive Memory Record is des ... https://www.psychologytools.com/resource/intrusive-memory-record/

Worksheet

Intrusive Thoughts Brain Metaphor

Intrusive thoughts are a common but sometimes distressing cognitive phenomenon. This information handout uses a simple metaphor to explain why we expe ... https://www.psychologytools.com/resource/intrusive-thoughts-brain-metaphor/

Information Handout

Learning To Relax (CYP)

Stress and tension are prevalent complaints amongst children and young people. Teaching relaxation exercises can engender a beneficial sense of contro ... https://www.psychologytools.com/resource/learning-to-relax-cyp/

Exercise

Making Sense Of Your Panic (Psychology Tools For Overcoming Panic)

Psychology Tools for Overcoming Panic takes a cognitive behavioral therapy (CBT) approach to this common anxiety problem. This chapter brings togethe ... https://www.psychologytools.com/resource/making-sense-of-your-panic-psychology-tools-for-overcoming-panic/

Chapter

Maximizing The Effectiveness Of Exposure Therapy

Despite its position as the leading treatment technique for anxiety disorders, not all clients respond to exposure therapy and some individuals relaps ... https://www.psychologytools.com/resource/maximizing-the-effectiveness-of-exposure-therapy/

Information Handout

Mindful Attention Audio Exercise

Mindful Attention (Audio)

Mindful Attention is a technique for becoming aware of one’s thoughts and experiences, and being able to observe these as transient mental events. ... https://www.psychologytools.com/resource/mindful-attention-audio/

Audio

Monitoring Your Panic (Psychology Tools For Overcoming Panic)

Psychology Tools for Overcoming Panic takes a cognitive behavioral therapy (CBT) approach to this common anxiety problem. This chapter introduces tec ... https://www.psychologytools.com/resource/monitoring-your-panic-psychology-tools-for-overcoming-panic/

Chapter

Motivational Systems (Emotional Regulation Systems)

At the heart of Compassion Focused Therapy (CFT) is an evolutionary model of human motivational systems. Developed by Paul Gilbert it is a helpful len ... https://www.psychologytools.com/resource/motivational-systems-emotional-regulation-systems/

Information Handout

Panic Attack Progress Record

Recovery often has a fluctuating course and it is important to monitor progress in cognitive behavioral therapy. Clients can use the Panic Attack Prog ... https://www.psychologytools.com/resource/panic-attack-progress-record/

Worksheet

Panic Attack Record Form

Self-monitoring of thoughts, feelings and symptoms is an essential skill for clients engaged in cognitive behavioral therapy (CBT). The Panic Attack R ... https://www.psychologytools.com/resource/panic-attack-record-form/

Worksheet

Panic Diary

The Panic Diary is a cognitive behavioral therapy (CBT) diary for panic symptoms. Clients can record panic attack frequency along with information abo ... https://www.psychologytools.com/resource/panic-diary/

Worksheet

Panic Symptom Tracker

Self-monitoring of thoughts, feelings, and symptoms is an essential skill in cognitive behavioral therapy (CBT). This symptom tracker helps clients to ... https://www.psychologytools.com/resource/panic-symptom-tracker/

Worksheet

Peaceful Place Audio Exercise

Peaceful Place (Audio)

The Peaceful Place exercise guides the listener through a short imagery exercise designed to facilitate the visualization of soothing imagery and noti ... https://www.psychologytools.com/resource/peaceful-place-audio/

Audio

Problem Solving (CYP)

Effective problem solving is an essential life skill and this Problem Solving worksheet is designed to guide children and adolescents through steps wh ... https://www.psychologytools.com/resource/problem-solving-cyp/

Worksheet

Progressive Muscle Relaxation

Progressive relaxation training originated in the 1930’s as a treatment for tension and anxiety. Edmund Jacobsen developed a systematic and lengthy ... https://www.psychologytools.com/resource/progressive-muscle-relaxation/

Exercise

Progressive Muscle Relaxation Audio Exercise

Progressive Muscle Relaxation (Audio)

The Progressive Muscle Relaxation exercise guides the listener through a sequence in which muscle groups are tensed and relaxed. ... https://www.psychologytools.com/resource/progressive-muscle-relaxation-audio/

Audio

Progressive Muscle Relaxation (Edition 1)

Muscle tension is one reaction to stress and anxiety. This exercise includes instructions for Progressive Muscle Relaxation, a technique for promoting ... https://www.psychologytools.com/resource/progressive-muscle-relaxation-edition-1/

Exercise

Psychology Tools For Living Well

Psychology Tools For Living Well

Cognitive behavioral therapy can help your clients to live happier and more fulfilling lives. Psychology Tools for Living Well is a self-help course ... https://www.psychologytools.com/resource/psychology-tools-for-living-well/

eBook

Psychology Tools For Overcoming Panic

Psychology Tools For Overcoming Panic

This helpful workbook will teach you everything you need to know about panic. Drawing upon the evidence base, Psychology Tools for Overcoming Panic  ... https://www.psychologytools.com/resource/psychology-tools-for-overcoming-panic/

eBook

Psychology Tools For Relaxation

Psychology Tools For Relaxation Audio Collection

The Psychology Tools For Relaxation Audio Collection is designed to help anyone experiencing stress or heightened physiological arousal. The audio col ... https://www.psychologytools.com/resource/psychology-tools-for-relaxation-audio-collection/

Audio Collection

Recognizing Agoraphobia

Agoraphobia is characterized by a marked fear of situations such as open spaces or public places. Recognizing Agoraphobia compares the DSM-5 and ICD- ... https://www.psychologytools.com/resource/recognizing-agoraphobia/

Information Handout

Recognizing Generalized Anxiety Disorder (GAD)

Generalized Anxiety Disorder (GAD) is characterized by an extended period of excessive worry. The DSM also emphasizes the importance of the client’s ... https://www.psychologytools.com/resource/recognizing-generalized-anxiety-disorder-gad/

Information Handout

Recognizing Panic Attacks And Panic Disorder

Panic attacks are characterized by sudden surges of intense fear or discomfort, and panic disorder is characterized by recurrent panic attacks. Recogn ... https://www.psychologytools.com/resource/recognizing-panic-attacks-and-panic-disorder/

Information Handout

Recognizing Social Anxiety Disorder

Social Anxiety Disorder is characterized by fear regarding social situations and individuals with social anxiety are concerned about negative evaluati ... https://www.psychologytools.com/resource/recognizing-social-anxiety-disorder/

Information Handout

Recognizing Specific Phobia

Specific phobia is characterized by marked fear or anxiety regarding a particular object or situation. Recognizing Specific Phobia compares the DSM-5 ... https://www.psychologytools.com/resource/recognizing-specific-phobia/

Information Handout

Relaxed Breathing

Practising Relaxed Breathing serves to reduce physiological arousal and can be an excellent grounding technique. This client information handout descr ... https://www.psychologytools.com/resource/relaxed-breathing/

Exercise

Relaxed Breathing Exercise 1

Relaxed Breathing Exercise 1 (Audio)

Breathing Exercise 1 guides the listener through simple instructions to make their breathing slower, deeper, and more regular. ... https://www.psychologytools.com/resource/relaxed-breathing-exercise-1-audio/

Audio

Relaxed Breathing Exercise 2

Relaxed Breathing Exercise 2 (Audio)

Breathing Exercise 2 uses the imagery of inflating a balloon to help the listener make their breathing slower, deeper, and more regular. ... https://www.psychologytools.com/resource/relaxed-breathing-exercise-2-audio/

Audio

Relaxed Breathing Exercise 3

Relaxed Breathing Exercise 3 (Audio)

Breathing Exercise 3 uses the imagery of breathing air of different colours to help the listener make their breathing slower, deeper, and more regular ... https://www.psychologytools.com/resource/relaxed-breathing-exercise-3-audio/

Audio

Relaxed Breathing Exercise 4

Relaxed Breathing Exercise 4 (Audio)

Breathing Exercise 4 guides the listener through simple instructions to breathe in a more relaxed fashion. ... https://www.psychologytools.com/resource/relaxed-breathing-exercise-4-audio/

Audio

Relaxed Breathing Record Form

Practising relaxed breathing serves to reduce physiological arousal and can be an excellent grounding technique. This record form helps clients to mon ... https://www.psychologytools.com/resource/relaxed-breathing-record-form/

Worksheet

Responses To Threat: Freeze, Appease, Flight, Fight

Human beings are programmed to respond automatically in a variety of ways to a threat including freezing, escaping, and dissociation. Traumatized indi ... https://www.psychologytools.com/resource/responses-to-threat-freeze-appease-flight-fight/

Information Handout

Assessment

Intervention

Treatment guidelines

Treatment manuals

Useful resources

Information Handouts

Generalized anxiety and mindfulness

Health anxiety

Panic

Panic

Phobia

Social anxiety

Social anxiety

Worksheets

Generalized anxiety and mindfulness

Panic

Social anxiety

Self-Help Programmes

Self-help programme for anxiety

Self-help programme for generalized anxiety and mindfulness

Self-help programme for health anxiety

Self-help programme for panic

Self-help programme for social anxiety

Presentations

Recommended Reading

General

Generalized Anxiety Disorder

A number of treatment packages have demonstrated efficacy in the treatment of GAD:

Laval model

Avoidance model of worry and GAD

Metacognitive model

Emotional dysregulation model

Acceptance-based model of GAD

Health Anxiety

Panic disorder

Social Anxiety Disorder

What Is Anxiety?

Signs and Symptoms of Anxiety Disorders

Different anxiety disorders are characterized by various foci of concern.

In addition to disorder-specific cognitive content, individuals experiencing anxiety disorders are likely to experience physical symptoms of anxiety including:

  • palpitations or accelerated heart rate
  • sweating
  • trembling or shaking
  • dry mouth
  • difficulty breathing
  • a feeling of choking
  • nausea or abdominal discomfort
  • dizziness
  • derealization or depersonalization
  • fear of losing control or passing out
  • fear of dying
  • hot flushes or cold chills
  • numbness or tingling
  • blushing
  • fear of vomiting
  • urgency or fear of urination or defecation

Psychological Models and Theories of Anxiety

One broad conceptualization of anxiety can be summarized by an ‘anxiety equation’ (Beck, Emery, & Greenberg, 1985; Salkovskis, Forrester, & Richards, 1998):

Anxiety = (perceived probability of therapy × perceived cost or awfulness of danger)

÷ (perceived ability to cope + perceived ‘rescue factors’)

Disorder-specific ‘CBT for anxiety’ cognitive models have been developed for all of the anxiety disorders. These are helpful in that they direct the therapist’s attention toward key interpretations and behaviors that act to perpetuate the anxiety disorders. For example, the critical mechanism that Clark identified in the cognitive model of panic (1986) is that body sensations are misinterpreted catastrophically as signs of danger, with concomitant effects upon emotions, behavior, and secondary cognitions.

Evidence-Based Psychological Approaches for Working with Anxiety

Cognitive behavior therapy has a strong evidence base for treating all of the anxiety disorders. Key components of CBT for anxiety interventions include exposure to the feared situations or stimulus, and an experimental approach to test the accuracy of beliefs.

Resources for Working with Anxiety

Psychology Tools resources available for working therapeutically with anxiety may include:

References

  • Beck, A. T., Emery, G., & Greenberg, R. L. (1985). Anxiety disorders and phobias: A cognitive perspective. New York: Basic Books.
  • Clark, D. M. (1986). A cognitive approach to panic. Behaviour Research and Therapy, 24(4), 461–470.
  • Salkovskis, P. M., Forrester, E., & Richards, C. (1998). Cognitive–behavioral approach to understanding obsessional thinking. The British Journal of Psychiatry, 173(S35), 53–63.

 

 

© 2020 Psychology Tools. All rights reserved