Panic Disorder and its Management

Panic disorder is a distressing form of anxiety characterised by unexpected panic attacks (with intense fear), which may be associated with situational avoidance. The first panic attack my be associated with a stressful episode but gradually the attacks become dissociated and occur "out of the blue". It is a chronic condition with relapses and leads to much distress and social dysfunction.¹ GABA receptor dysfunction is thought to play an important role in panic disorder pathophysiology, but there are also important genetic and environmental factors involved.

Panic disorder can also be associated with the use of certain medications: SSRIs, benzodiazepine withdrawal and withdrawal from zopiclone. These should be considered in assessing any patient who presents with panic disorder.

• Lifetime prevalence between 1 - 3 % (one of the commonest psychiatric disorders).
• Familial tendency.
• Bimodal peak in age of onset - late adolescence and mid thirties.²

• Commonly unrecognised and untreated.
• Most patients are seen in general practice, although patients may present to A & E with somatic symptoms e.g. chest pain.
• Due to the physical symptoms the diagnosis of panic attacks may not be made. Therefore, a high index of suspicion is needed. Screening tools are available.^3,4
• Although a good description of the episode may suggest a panic attack, it is important to exclude other organic conditions. For example, there is a case report of a cingulate ganglioma presenting as panic attacks in a teenager.⁵
• It is also important to remember that panic attacks may be a feature of other psychiatric diagnoses e.g. schizophrenia and depression.

1. Full medical history (differential diagnoses include hyperthyroidism, Cushing's disease, neurological disorders).
2. Full psychiatric history, including suicidal ideation.²
3. Substance abuse (also ask about over-the-counter medicines and herbal remedies).
4. Full physical examination.
5. Baseline investigations based on findings e.g. ECG and ECHO and/or stress test for chest pain, cardio memo for palpitations.

Always try to involve family or carers if patient allows.

Patient education

1. Avoidance of agoraphobia.
2. Avoid anxiety-provoking substances e.g. caffeine.

Cognitive behavioural therapy, followed by SSRIs and then self help are best, in descending order, at achieving the longest symptom free period.^2,6,7 However, it should be noted that SSRIs can cause panic attacks in some patients and are used to treat the same in others.

Non-pharmacological

• Relaxation techniques: this usually involves learning coping strategies and there is evidence that this is an effective method of treatment for panic disorders. However, this benefit has only really been demonstrated in patients without agoraphobia.⁸
• Education and supportive therapy: this can involve exposure therapy e.g. therapist accompanied or self exposure. However, exposure techniques can be very distressing for the patient.⁹
• Cognitive and behavioural therapy and their combination: this involves cognitive therapy and interoceptive exposure where by changes in pulse rate and breathing that occur with panic attacks are identified and attempts at stopping these are made. Cognitive-behavioural therapy (CBT) in panic disorder has had good results, for example, in one trial 8 weeks of CBT resulted in more than 60% of patients not relapsing at 6 months. These benefits are seen both in group and individual based CBT.¹⁰
• Insight orientated psychotherapy.

Pharmacological

1. Selective serotonin reuptake inhibitors:
   • These are first line medication for panic disorder and examples include fluoxetine and paroxetine.^2,11
   • They are preferred in comparison to tricyclic antidepressants (TADs) as they have a better safety profile.
2. Tricyclic antidepressants (TAD):
   • Examples include: imipramine (most studied), clomipramine or nortriptyline. These are second line and should be used if SSRIs can not be used or if no response with SSRIs after 12 weeks.
   • Takes 3-4 weeks for onset of action and usually need six months therapy.
   • Side effects are common and this can result in poor compliance e.g. anticholinergic side effects (dry mouth and constipation) or postural hypotension.
   • For maximum benefit from TADs complementary treatment for agoraphobia is necessary; where patients face the situations that lead to panic attacks.
3. Benzodiazepines:
   • All benzodiazepines are of equal efficacy.
   • They are sedative and can impair concentration and reaction times.
   • They have a rapid onset and reduce vigilance.¹¹
   • However, tolerance and dependence can occur.
   • They are therefore not currently recommended in the treatment of panic disorder.²
4. Anti-histamines:
   • These have been used but their sedative side effect limits their use.
   • Also their efficacy in panic attacks has not been well established.
   • They are therefore not currently recommended in the treatment of panic disorder.²
5. Beta blockers:
   • Propranolol has been used but it does not relieve anxiety, rather it reduces the physical symptoms, such as tachycardia.^12,6
   • They are therefore not currently recommended in the treatment of panic disorder.
6. Current experimental therapies:
   • Agents that increase GABA concentrations in the central nervous system, such as vigabatrin and tiagabine, have been shown to reduce panic attacks and anxiety in experimentally induced panic attacks.¹³
   • Also buspirone has been used in chronic anxiety with good outcome - it also has the added benefit of not causing dependence nor tolerance.¹³
   • Newer atypical antipsychotics are also promising to be of benefit but are still only at the clinical trial stage e.g. arpiprazole.¹⁴

1. Review at two weeks - looking for side effects.
2. Review again at 4, 6 and 12 weeks.²
3. If improvement at 12 weeks continue for 6 months and then consider gradual dose reduction with a plan to discontinue medication.
4. If no improvement at 12 weeks try TAD.
5. If no response despite trial of SSRIs or TADs then refer to specialist mental health services.
6. Self-complete questionnaires should be used to assess outcomes.¹⁵