Running Head: OVERVIEW OF GENERALIZED ANXIETY DISORDER
Generalized Anxiety Disorder Term Paper: Overview of Clinical Aspects
Çağıl Doğan
Abant İzzet Baysal University,
Clinical Psychology M.S.
Abstract
In this overview, literature about generalized anxiety disorder is searched for and discussed here with clinical aspects. As well as defining the key terms about anxiety or worry related terms, disorder is also defined and tried to discriminate with other disorders with theoretical models are explained, diagnosis and diagnostic validity issues are handled. Then frequency and characteristics of the GAD is viewed from biological, psychosocial, and cultural perspecttives with its etiology and risk factors. Then assessment and cognitive behavioral therapy techniques and modules questioned that assessing severity and recovering of GAD.
Key Terms: generalized anxiety disorder, cognitive behavioral therapy, worry
Generalized Anxiety Disorder Term Paper: Overview of Clinical Aspects
Before making statements about the psychopathological diagnosis of any disorder it is an important reminder that checking the key terms backgrounded. Since it is kind of a new construct as a distinct disorder, Generalized Anxiety Disorder (GAD) should be carefully handled in both clinical and research settings (Weisberg, 2009). Discriminating the meaning of anxiety, worry, fear, phobia, panic attack, and obsessions may have essential role describing and explaining the psychological disorders. Anxiety refers to a more general term with an anticipation of a problem associated with thinking about the future while the fear is just happening at exposing situation to danger (Oltmanns & Emery, 2010). As a specific term, panic attack is more focusing the self while excessive anticipating the fear of the provoking situation (2010). The other specific term obsession is repetitive imagination or acts those are unwanted (2010). Phobia is stable, shallow fears to specific object or situation and distinguished with the fear as being not reasonable (2010). Worry is one of the most controversial terms in literature while discussing the GAD and its severity level’s effects on diagnostic reliability (Andrews, et. al., 2010). Although excessive worrying defined as inflated thinking with negativity and emotionality related with the upcoming threats or possible bad issues (Oltmanns & Emery, 2010). It is an important issue distinguishing the term of normal worry with the pathological worry (Andrews, et. al., 2010). Pathological worry defined as that thinking part is consuming too much time and energy that makes the individual impaired in daily activities rather than doing the work effectively and easily (APA, 2013). Another way to reveal the difference between normal and pathological worry is assessing that with its quantity, quality, and duration (Oltmanns & Emery, 2010).
In this paper, it is aimed that the focusing on the definition, theoretical models, diagnosis criteria, epidemiology, etiology, and the cognitive behavioral treatment models will be served as an overview for GAD to understand the concept better in a harmony.
Definition of GAD
Since GAD is defined as a new term with its announcement at DSM-III, it is still an issue that waiting growth for its maturity (Weisberg, 2009). Clients with generalized anxiety disorder is having too much anxiety and apprehension, and cannot control its worry in duration of more days than not for at least six months, within distortions in numerous events or activities including vocational and academic activities (APA, 2013). Moreover, significant distress is experienced by clients (Olttmanns & Emery, 2010). Rygh and Sanderson (2004) distinguished the pathological and non-pathological worry with physiological symptoms does not generally occur in that disorder but having a pervasive with high intensity and frequency is expected. The future and its threats are crucial element for thinking rather than living and getting the pleasure in the present. Therefore, they have difficulty in focusing on one thing and excessively arguing in their mind (Dugas & Robichaud, 2007). In additionally, GAD has a stable pattern over time and its impairment shows similar results with major depressive disorder with its risk for suicide (Weisberg, 2009). Suicide risks have proven with other studies (Avcin & Konecnik, 2013). It is argued that the comorbidity is common; therapy success is challenged by changes between depression and anxiety, physical complaints are taking essential role, and it is the most seen among psychological disorders (2013). Since its prevalence rates are sensitive to the diagnostic criteria of duration, there is a risk of underdiagnosing the patients (Andrews et. al., 2010; Avcin & Konecnik, 2013; Weisberg, 2009). Therefore, GAD could be explained as a disorder that is leading to psychosocial defects as well as somatic issues associated with extensive worrisome thoughts while anticipating the future.
Theoretical Models
Enhancing the definition and schematizing the disorder with a theoretical basis would be helpful for not only to understand the explanation but also to draw a treatment process.
Borkovec’s Avoidance Theory
Rygh and Sanderson (2004) summarized that in their textbook as Borkovec’s theory refers to worries as coming to the individual’s mind, but it is then avoided and turning into several somatization or emotional state. External and internal events may strengthen the avoidance with the extensive work of false self-conceptualization (2004). It is stated that treatment of this disorder could be structured with various techniques consisting the response prevention referring to planning the periods those are worried is allowed or worried is not allowed according to the borders learned from therapist; worry outcome monitoring refers to the encouragement of recording the feared consequence and comparing with the actual consequence that is recorded also, therefore the client may enhance the ability of perception of possible outcomes coming from the future; present-moment focus of attention is about using both methods of relaxation techniques and cognitive radio those are instructed from therapist; imagery is about to reorganize and developing efficient coping style for the old thoughts with imagining that; targeting core fears avoided through worry is about the dealing with the exact event such as traumatic experience, earlier negative relationships and current communication problems (2004). Self-control desentization, cognitive restructuring, expectancy free-living are other techniques founded to be useful with empirical evidences (Behar et. al., 2009).
The Intolerance of Uncertainty Model
It is stated that confronting with uncertain situation and its possible upcoming negative results is found to be stressful and must be avoided task is sourced from individual’s disposition to not compensating those situations (Dugas & Robichaud, 2007). Those people who have difficulty to tolerate the confronting events are risk at developing the GAD because they are commenting about threats with only limited information about, performing badly in if they could not foreseeing the activity, and if they have lack of self-confidence (2007). Treatment process would briefly include that self-monitoring, education about intolerance, considering the worry beliefs, getting better problem awareness, and targeting the core beliefs (Behar et. al., 2009).
Well’s Metacognitive Model
It is known that GAD is based on the worries i.e. cognition part. That’s why the researchers needed to examine its metacognitive processes which are regarded as seeing the worries with worrisome clothes (Rygh & Sanderson, 2004). Metacognition starts with the first step of only worrying about things it is discussed above, then in the second step starting to thinking negatively about your worries commonly called as metaworry (2004). Cognition about the cognition in a negative way may lead to worsening the outcomes of the disorder. For example, muscle tension occurred when the individual processing negative thoughts, then individual starts to thinking negatively about how worries lead to the muscle tension that makes the worries strengthened. Treatment includes inducing the right case formulation, discussing the difficult to control and threat parts of the worries, as well as positive worry beliefs which refers to the meaning of worries are beneficial to survive from the client with GAD.
Diagnosis
To begin with the development of the GAD term, it is necessary to remember its evolution starting from anxiety neurosis a psychoanalytic explanation to the DSM-V’s GAD explanation. The milestone that, with DSM-III which is announced at the 1980, the anxiety neurosis term divided into two concepts with panic disorder and the generalized anxiety disorder that is defined with the nature of generalized and persistent course as well as one month duration; then DSM III-R changed the diagnostic criteria seeking for the unreal, exaggerated type of the worry with six month duration, then to DSM-IV and DSM-V into the excessive anxiety and worry (Weisberg, 2009; APA, 2013). In the present form of the DSM, to making a diagnosis with GAD in first step it is expected that anxiety and worries should impair the daily activities, leading difficulty to manage it, not aware of why worries are stemmed, and problem cannot explained better with other disorder’s key terms (APA, 2013). Three or more symptoms are needed to make diagnose (one criterion is enough for children): impetuosity, being exhausted easily, concentration problems and empty thinking, irritability, muscle tension and sleep disturbance (2013).
DSM-IV-V & ICD-10
Nilsson (2012) compared the diagnostic issues and concluded that DSM III-R and ICD-10 is having more bonding than the DSM III-R and DSM-IV; while worry is an integral part of DSM, worry is only a part of criteria for ICD-10; ICD-10 includes more symptoms listed than DSM-IV except that fatigue problems listed only in DSM-IV and DSM-V. Although prevalence rates are similar while ICD-10 or DSM-IV diagnostic criteria used, it is also found that their diagnoses related to the different people (Nilsson et. al., 2012; Slade & Andrews, 2001). Even ICD-10 found to be restrictive while diagnosing the patient, DSM-IV-V is found to be more limited to reveal the individual with significant problems (Nilsson et. al., 2012).
Differential Diagnosis
Since the basic terms which are discussed before easily confused or there is a difficulty making inferences might lead to mistakes, it is necessary to differentiate the diagnostic criteria with other disorders. First of all terms of depression and anxiety generally shared with each other: while fear, anxiety, panic attacks, pain, gastrointestinal complaints, excessive worry, agitation, concentration difficulty, sleep disorder, fatigue, tiredness and suicide thoughts are shared items between depression and anxiety; emotional hyperarousal, agoraphobia and compulsions belongs to only-anxiety and depressed mood, loss of interest, lack of pleasure, weight changes belongs to only-depression (Türkçapar, 2004). Therefore, it is expected that the anxiety and depression terms are not easily distinguishable as well as major depressive disorder and generalized anxiety disorder. As a consequence, the key parts of disorders could only differentiate the diagnosis. For example, panic disorder is different with its anxiety about having a panic attack, negative social evaluation and performance anxiety is related with the social anxiety disorder, obsessions to specific things or checking rituals belongs in obsessive-compulsive disorder, traumatic events related with the post-traumatic stress disorder and so on (APA, 2013). Moreover, differentiating the pathological worry and normal worry is also important and criticized before the establishment of DSM-V (Andrews, et. al., 2010). APA (2013) defines the distinction as normal concerns are different than pathological worry with its significant and pervasive problem on daily life, and its management not possible, symptoms are presented in long duration, with larger range and greater intensity and distress; and more significant physical complaints accompanied with such as muscle tension.
Limitations and Critiques
Therefore, it is argued that from Andrews and colleagues (2010) worry part must be the most important thing, and changing the word of excessive worry to difficult to control worry and changing the duration may aid the inter-rater reliability issues. Also having too much comorbidity with unipolar mood disorders and anxiety disorders and danger of underdiagnosing the individuals are questioned in the literature (Nilsson, et. al., 2012; Avcin & Konecnik, 2013). Also its sensitive to duration construct of GAD is accepted with many authors (Weisberg, 2009; Andrews, et. al., 2010).
Epidemiology
Generalized anxiety disorder is known to be highly prevalent, comorbid with other psychological disorders, and having a dispositional persistent pattern over time by many professionals (Weisberg, 2009; Nilsson et. al., 2013; Avcin & Konecnik, 2013; APA, 2013).
Prevalence
Because diagnostic criteria conditions are playing a role on the frequency of this disorder, prevalence ratio is changing between studies to another one. National comorbidity survey replication found to be life time prevalence as 5.7% and one year prevalence as 3.1% for GAD (Weisberg, 2009). In United States population 2.9% for adults and 0.9% for adolescents are indicating the one year prevalence rate and life time prevalence is reaching up to 9% (APA, 2013). While considering other countries one study found the one year prevalence rate 0.1% to 6.9% in Europe (Lieb & Becker, 2005). Another study states that other countries 1 year prevalence is between 0.4% and 3.6% (APA, 2013). With ICD-10 diagnose, highly variable one month prevalence rate found among different cities of the world from 1% to 22.6% (Maier, et. al., 2000).
Characteristics. Although, median age of onset of GAD is about the 30, its prevalence reached the highest rate in middle age that may be explained by the workload of the past problems creating the excessive anxiety then (APA, 2013). It is also found to be two times more prevalent in females; more prevalent at European peer than non-European as well as developed countries than non-developed countries (2013). Since we have known that recovering from this disorder could be challenging, it is also stated that lack of familial connection, being female, comorbid personality disorders and other psychological disorders are important properties makes the treatment difficult (Weisberg, 2009).
Culture. When depression is controlled GAD severity is same between Turkish population and immigrant in Germany as Turkish population. Lack of social support may be the reason in increase of GAD with depression (Altunoz et.al., 2014).
Comorbidity
In late adulthood comorbidity of depression is found to be higher than other disorders (Nilsson, et. al., 2013). Likewise, comorbidity with unipolar psychological disorders (clinical depression, dysthymia etc.) and other anxiety disorders are found to be common (APA, 2013). Comorbidity results show that GAD is having an independent role with psychosocial and cognitive impairment (Nilsson, et. al., 2013). It is also found to be diagnostic criteria changes the comorbidity with 90% in ICD-10, 84% in DSM-IV and, 74% in DSM-V.
Etiology
In addition to the theoretical models that we discussed before, it is needed to find causes to understand the GAD better.
Biology
Genetic basis is exist among anxiety and mood disorders, however specificity is explained by environmental factors (Rygh & Sanderson, 2004). Modestly heritable 20%-30% of variance is explained for transmission between heritages (Oltmanns & Emery, 2010). Almost one of third is found to have genetic basis (APA, 2013). There are specific pathways in the brain for responding to the danger where amygdala and thalamus plays significant role in circuits of these pathways; also neurotransmitters of serotonin, norepinephrine, GABA and dopamine are found to be associated (Oltmanns & Emery, 2010).
Environmental
Rygh and Sanderson (2004) summarized from literature that, couples with problems are having GAD, especially females are vulnerable; if the family environment is tried to be controlled harshly this may lead to lack of sense of control, losing internal locus of control and negative emotionality; criticism sourced by parents could having a role; as well as physical traumas.
Risk Factors
Approaching to a psychological disorder from risk factors i.e. increasing tendency to having this disorder is especially beneficial while understanding with real life settings are necessary. Interestingly it is found that children having frequent and pervasive physical distress with somatic complaints are strongly linked to GAD in young adulthood (Shanahan et. al., 2015). Experience of divorce and widow, lack of economical sources, and age as demographic factors; traits, both childhood and adulthood stressful events as environmental and personality factors; also history of psychiatric treatment as well as occurrence of any psychological disorder in family or self are linked to the risk of having GAD (Moreno-Peral et. al., 2014). Moreover, temperamental factors are playing role, such as lack of behavioral disclosure, neurotic personality associated with GAD; overprotective attitude and negative childhood experiences are related (APA, 2013).
Assessment
GAD-7
Although there are numerous numbers of anxiety and depression scales, GAD-7 is one of the most common scale specifically founded to help assessment of generalized anxiety level. In its Turkish adaptation with named of YAB-7 is found to be reliable and valid measurement and also found to be significantly sensitive when control groups scores are compared (Konkan et. al., 2014).
Interviewing
In addition to psychometric instruments, it is needed to use the interview skills to be able to sure eliminating the statistical errors (false positives and true negatives) as much as possible. Dugas and Robichaud (2007) summarized the clinical interviewing with four parts:
GAD Worry. Stressors (family, relationships, health, finance, school, work etc.), changes-transitions (both positive and negative) and difficulties should be questioned
GAD Somatic Symptoms. To reach three out of six: restlessness or feeling keyed up or on edge, being easily fatigued, difficulty concentrating or mind going blank, irritability, muscle tension, and sleep disturbance; muscle tension is unique to this disorder.
Impairment and Distress. Checking the whether there is significant distress or complication in their life caused by the symptoms and how severe the symptoms where their excessive worry is may be normal to them
Worry. Checking the if worries are be frequent, intense, widespread, and difficult to control.
Treatment
Two main types of GAD treatment are considered widely: medication and psychotherapy (Avcin & Konecnik, 2013).
Medication
Although long term effects and dependency issues are not studied extensively it is recommended that medication could be used if only in no benefits by psychological approach (Rygh & Sanderson, 2004). Benzodiazepines are good for fast relief but having tolerance-dependency problem while azapirones having no withdrawal problem, and efficient against worry, tension, irritability. SSRI’s, tricyclic antidepressants, selective serotonin-norepinephrine reuptake inhibitors and antipsychotics could be handled in pharmacological treatment (2004).
Psychological Interventions
Although there are numerous schools of therapy those would be beneficial in some degree for treating GAD, cognitive behavioral therapy is the most studied and found efficient with evidences for internal and external validity (Rygh & Sanderson, 2004; Avcin & Konecnik, 2013). The ultimate goal of therapy is trying to find alternative coping behavioral, emotional and cognitive parts of worrying rather than destroying all beliefs belongs to the client; alternating the anticipating of threats, developing proper overcoming techniques and explaining the operant and classical conditions (Rygh & Sanderson, 2004).
Four approaching styles and associated techniques will be discussed here with respect to the Rygh and Sanderson (2004) work: cognitive, physiological, behavioral and, associated problems.
Cognitive Intervention Techniques. Psychoeducation, used as review of fear, anxiety, worry and its nature i.e. explaining whole concepts, dictating the structure to the client and it is essential for cooperating in treatment.
Cognitive restructuring refers to reevaluating the opinions and responses to environmental and internal stimulus with tools such as worry episode log included images, beliefs, assumptions, and thoughts are noted; guided discovery and catastrophizing includes socratic questioning and facing with emotional difficulties in treatment; developing alternative viewpoints is using the third person, role playing, reframing techniques; hypothesis testing refers to the developing rational responses to check new interpretations and conducting real life experiment with concrete data.
Positive imagery is a technique that specific stimulus is matching with the realistic positive imagery i.e. parasympathetic nervous system corresponding with the sympathetic system; therefore new stimulus reminds the positive images.
Worry exposure is about allowing conscious processing of emotionally triggered sensations after the long exposure for being used to that.
Improving problem orientation is aimed that finding the key elements classified as major & minor, possible & not possible threats and teaching that preparing solution to only for major and possible threats conditions
Cost-Benefit analysis of coping is a structured view of behaviors and cognitions via advantages and disadvantages.
Cognitive response prevention is used for interrupting and postponing to worrisome responses to stimuli in future or to limited conditions with scheduled worry time is assigning the appointments for worries under more and more restricted conditions; worry-free zones are periods of times that individual could not worry i.e. worrisome thoughts must be delayed to another time.
Physiological Intervention Techniques. Progressive muscle relaxation is used knowing the where tension occurs, then altering it by discriminating muscle groups.
Diaphragmatic breathing is learned in sessions then making the breathing autonomic therefore externalizing the relaxed breathing to natural conditions.
Self control densentization is used for self-control rather than counterconditioning; client learned how to aware anxiety and converting to relaxed state
Applied relaxation is using the relaxation during daily life.
Behavioral Intervention Techniques. Behavioral response prevention is used to reduce excessive coping behavior.
In vivo exposure is step by step gradually experience of stimulus.
Pleasurable Activity Scheduling is reorganizing activities those were prohibited in the past because of excessive worry and anxiety.
Associated Intervention Techniques. Mindfulness is altering the avoidance by thinking here and now
Emotional processing and regulation training is related with being aware of emotional climate and regulating it rather than leading in worries
Interpersonal effectiveness is effort to increase the beneficial interpersonal interactions, then reaching more agreement between the individual and others
Time management is used for balancing the consistency of one’s goals i.e. planning and scheduling activities according to hierarchy of needs of their own.
Focusing on Worry in Treatment
Dugas and Robichaud (2007) brings different approach to psychotherapy that focusing worries rather than giving importance because with the disorder’s pervasive, excessive, difficult to control of worries, somatic symptoms are just results of worries. Therefore, worries should be studied directly to have better tolerance to uncertainty; to decrease the somatic symptoms is only possible with decreasing the worrisome thoughts (2007).
With the respect of Dugas and Robichaud’s work (2007), it is listed as they divided treatment into modules within each special roles exist:
Psychoeducation and Worry Awareness Training. In this first module, education of CBT is handled with its cognition-behavior-affect cycle, rethinking of problems, client-therapist’s alliance, tool usage (e.g. self-report homework), simple and rigid sessions, dominancy of structure is felt, working with here and now principles and using exercise are all explained to the client. Also, GAD is explained especially with its pervasive and with its basement on excessive worries; and current or hypothetical situations are identified via worry awareness training.
Uncertainity Recognition and Behavioral Exposure. Second module is used for helping the client to understand the association between difficulty in tolerance and exaggerated worries, revealing the unavoidable pattern of uncertainty, and encouraging to experience these situation on their own.
Reevaluation of the Usefulness of Worry. In this module, it is altered that whether the worries are really useful or they are just coming from the wrong positive belief – a reconsideration is used.
Problem-Solving Training. Teaching that solving the problem is better way than just thinking about it excessively. Both enhancing the orientation of problem and applicable solving skills are studied.
Imaginal Exposure. Although application of problem solving is encouraged in this chapter, therapist and client is figuring out the conditions those may not be used in daily life for possible reasons.
Relapse Prevention. The last module is important to briefly reconsider learned in sessions, encouragement and talking about future practices as well as revealing the improvement and showing the treatment progress to the client.
Other Therapeutic Implications
Recovery in metacognitive therapy reaches up to 80% and greater to only applied relaxation (Wells, et. al., 2009). While treating GAD with its both depressive and anxiety related symptoms music therapy found to be beneficial (Gutierrez & Camerana, 2015). Emotion regulation therapy (ERT) is making the client showing advancement even in three or nine month period (Mennin, et. al., 2015).
Conclusion
This paper aimed at an overview of the literature for generalized anxiety disorder specifically. It is stated that people with GAD are having a tendency to be persistent, intense, frequent in pathological worries and duration have significant role on prevalency rates as well as GAD is highly comorbid with unipolar disorders and low in interrater reliability in diagnosis with also cultural studies showing variations. Then risk factors for onset is discussed and found to be usually related to environmental (social) factors. Then assessment and treatment from different aspects are discussed as cognitive, behavioral, physical and environmental level could be worked in treatment with aids of the client’s compliance.
References
Altunoz, U., Ozel-Kizil, E. T., Kokurcan, A. & Graef-Calliess, I.T. (2014). Native Turkish patients and Turkish immigrants: a comparison in terms of clinical features of generalised anxiety disorder. European Neuropsychopharmacology. 24, 599- 600.
Andrews, G., Hobbs, M. J., Borkovec, T. D., Beesdo, K., Craske, M. G., Heimberg, R. G., Rapee, R. M., Ruscio, A. M. & Stanley, A. M. (2010). Generalızed worry disorder: a review of dsm-ıv generalized anxiety disorder and options for dsm-v. Depression and Anxiety. 0, 1-14.
Avcin, B. A. & Koncecnik, N. (2013). Generalised anxiety disorder. Slovenian Medical Journal. 82.
Behar, E., DiMarco, I. D., Hekler, E.B., Mohlman, J. & Staples, A. M. (2009). Current theoretical models of generalized anxiety disorder (GAD): conceptual review and treatment implications. Journal of Anxiety Disorders. 23, 1011-1023.
Dugas, M. J. & Robichaud, M. (2007). Cognitive behavioral treatment for generalized anxiety disorder. New York: Taylor & Francis.
Gutierrez, E. O. F. & Camerana, V. A. T. (2015). Music therapy in generalized anxiety disorder. The Arts in Psychotherapy. 44, 19-24.
Konkan, R., Senormancı, Ö., Güçlü, O., Aydın, E. & Sungur, M. Z. (2013). Yaygın Anksiyete Bozuklugu-7 (YAB-7) Testi Türkçe Uyarlaması, Geçerlik ve Güvenirligi. Archives of Neuropsychiatry. 50, 53-58.
Maier, W., Gansicke, M., Freyberger, H. J., Linz, M., Heun, R. & Lecrubier, Y. (2000). Generalized anxiety disorder (ICD-10) in primary care from a crosscultural perspective: a valid diagnostic entity?. Acta Psychiatrica Scandinavica. 101, 29- 36.
Mennin, D. S., Fresco, D. M., Ritter, M. & Heimberg, R. G. (2015). An open trial of emotion regulation therapy for generalized anxiety disorder and cooccurring depression. Depression and Anxiety. 32, 614-623.
Moreno-Peral, P., Conejo-Ceron, S., Motrico, E., Rodrigues-Morejon, A., Fernandez, A., Garcia- Campayo, J., Serrano-Blanco, A., Rubio-Valera, M. & Bellon, J. A. (2014). Risk factors for the onset of panic and generalised anxiety disorders in the general adult population: A systematic review of cohort studies. Journal of Affective Disorders. 168, 337-348.
Nilsson, J., Östling, S., Waern, M., Karlsson, B., Sigstörm R., Guo, X. & Skoog, I. (2012). The 1-month prevalence of generalized anxiety disorder according to DSM- IV,DSM-V, and ICD-10 among nondemented 75-year-olds in Gothenburg, Sweden. The American Journal of Geriatric Psychiatry. 20, 963-972.
Oltmanns, T. F. & Emery, R., E. (2010). Abnormal psychology (6th ed.). New Jersey: Prentice Hall
Rygh, J. L. & Sanderson, W. C. (2004). Treating generalized anxiety disorder: Evidence- based strategies, tools, and techniques. New York: The Guilford Press.
Shanahan, L., Zucker, N., Copeland, W. E., Bondy, C. L. & Costello, E. J., (2015). Childhood somatic complaints predict generalized anxiety and depressive disorders during young adulthood in a community sample. Psychological Medicine. 45, 1721-1730.
Slade, T. & Andrews, G. (2001). DSM-IV and ICD-10 generalized anxiety disorder: discrepant diagnoses and associated disability. Social Psychiatry and Psychiatric Epidemology. 36, 45-51.
Türkçapar, H. (2004). Anksiyete bozukluğu ve depresyonun tanısal ilişkileri. Klinik Psikiyatri. 4, 12-16.
Weisberg, R. B. (2009). Overview of generalized anxiety disorder: epidemiology, presentation, and course. Journal of Clinical Psychiatry. 70, 4-9.
Wells, A., Welford, M., King, P., Papageorgiou, C., Wisely, J. & Mendel, E. (2009). A pilotrandomized trial of metacognitive therapy vs applied relaxation in the treatment of adults with generalized anxiety disorder. Behaviour Research and Therapy. 48, 429–434.