Background The assignment was to examine various methods of treating the established anxiety disorders. Intervention to alleviate non-specific symptoms of worry, apprehension and anxiety were not part of the assignment. The assessment included the treatment of children, adolescents and adults with:

• Panic disorder (PD)
• Obsessive-compulsive disorder (OCD)
• Post-traumatic stress disorder (PTSD)
• Generalized anxiety disorder (GAD)
• Specific phobias.

• For each anxiety disorder, one or more treatments have proven to be effective (strong scientific evidence). With the exception of specific phobias, both pharmacological treatment and psychotherapy are moderately effective. The symptoms are alleviated, but full remission is rarely achieved. With a few exceptions, the symptoms recur once treatment has been completed.
• The socioeconomic costs – primarily in terms of lower productivity, as well as greater ill-health, death rates and the need for somatic care (treatment for physical symptoms) – are high. The cost effectiveness of various treatment options has not been determined.
• There is insufficient scientific evidence for comparing either the efficacy or cost effectiveness of different treatments.
• Studies of psychodynamic therapies are almost totally lacking.
• Some benzodiazepines have been shown to be effective in treating certain anxiety disorders. However, it has been well established that the drugs cause significant problems in terms of side effects, dependence or an exacerbation of symptoms after treatment has proceeded for a certain period of time.
• No study has unequivocally explained why anxiety disorders are associated with raised death rates. Long-term studies on how to reduce raised death rates through some form of intervention are lacking.

Panic disorder (PD), with or without agoraphobia (fear of having a panic attack in a place from which escape would be difficult)

• The antidepressants sertraline, paroxetine, imipramine and clomipramine (strong scientific evidence), as well as most likely citalopram and moclobemide (limited scientific evidence), reduce the frequency of panic attacks. Agoraphobia is only slightly affected by antidepressants (moderately strong scientific evidence).
• Exposure to the situations that cause panic alleviates the symptoms of agoraphobia with PD (moderately strong scientific evidence).
• Cognitive behavioral therapy (CBT) that includes exposure alleviates the symptoms of PD without agoraphobia or with mild to moderate agoraphobia (strong scientific evidence). Its effectiveness for PD with severe agoraphobia has not been established. Exposure as a monotherapy alleviates the symptoms of agoraphobia (moderately strong scientific evidence).
• Psychotherapy has a more long lasting effect than psychotropic drugs (moderately strong scientific evidence).
• Antidepressants and CBT or exposure have proven to be more effective in combination than as monotherapies (moderately strong scientific evidence).

Specific Phobias

• Exposure, modeling and participant modeling, in which the patient learns to handle whatever triggers the fear, has a substantial, long-term impact on specific phobias (strong scientific evidence).
• There is no proven pharmacological treatment for specific phobias.

Social Anxiety Disorder (SAD)

• Fluvoxamine, sertraline, paroxetine, venlafaxine and escitalopram alleviate the symptoms of SAD (strong scientific evidence).
• CBT, particularly in a group setting, alleviates the symptoms of SAD (strong scientific evidence).
• Antidepressants and psychological therapies have not proven more effective in combination than when administered separately (moderately strong scientific evidence).

Obsessive-Compulsive Disorder (OCD)

• Clomipramine, sertraline, paroxetine, fluoxetine, fluvoxamine (strong scientific evidence) and citalopram (moderately strong scientific evidence) alleviate the symptoms of both obsessions and compulsions. The drugs are effective as long as they are being administered, but most patients relapse once the treatment has been terminated (moderately strong scientific evidence).
• Behavioral therapy (exposure / response prevention) reduces the symptoms in approximately half of all patients with compulsions (strong scientific evidence). The effect remains at two-year follow-up (moderately strong scientific evidence).

Post-Traumatic Stress Disorder (PTSD)

• Fluoxetine, sertraline and paroxetine alleviate the symptoms of PTSD (strong scientific evidence). Sertraline remains effective at one-year follow up (strong scientific evidence).
• Various kinds of repeated exposure to that which is reminiscent of the traumatic event (strong scientific evidence) and CBT (moderately strong scientific evidence) alleviate the symptoms of PTSD.
• Eye Movement Desensitization and Reprocessing (EMDR), which combines eye movements with behavioral therapy, is effective for PTSD (moderately strong scientific evidence), but the eye movements lack specific therapeutic value (strong scientific evidence).

Generalized Anxiety Disorder (GAD)

• Paroxetine, venlafaxine (strong scientific evidence), sertraline and escitalopram (moderately strong scientific evidence) alleviate the symptoms of GAD.
• CBT is effective for GAD (moderately strong scientific evidence).

Treating Children and Adolescents

• CBT alleviates the symptoms of separation anxiety disorder, overanxious disorder, GAD and SAD (strong scientific evidence). The effect remains at two-year follow-up (moderately strong scientific evidence). Fluoxetine, paroxetine, sertraline and fluvoxamine have proven to alleviate the symptoms, but none of them has been approved for these disorders in children and adolescents.
• Exposure to the feared object or situation is effective for patients with specific phobias (strong scientific evidence).
• Clomipramine, sertraline, fluoxetine (strong scientific evidence), paroxetine and fluvoxamine (moderately strong scientific evidence) alleviate the symptoms of OCD. Clomipramine, sertraline and fluvoxamine have been approved for treatment in children and adolescents.
• Behavioral therapy, whether CBT or not, is equally effective as antidepressants for treating OCD (strong scientific evidence). Combination treatment is somewhat more effective (strong scientific evidence).
• CBT alleviates the symptoms of PTSD (moderately strong scientific evidence).