Thirty years ago panic disorder was officially recognized as a distinct psychiatric condition. Since then it has become extensively studied compared to other anxiety disorders.
Panic disorder is fairly common in the general population. Among all anxiety disorders, it has the highest number of medical visits and serves as a very costly mental health condition.
Panic disorder is characterized by recurrent, unexpected panic attacks. Panic attacks are defined by the Diagnostic and Statistical Manual of Mental Health Disorders (DSM) as “an abrupt surge of intense fear or discomfort” reaching a peak within minutes. Four or more of a specific set of physical symptoms accompany a panic attack. Panic attacks occur as often as several times per day or as infrequent as only a few attacks per year. A hallmark feature of panic disorder is that attacks occur without warning. There is often not a specific trigger for the panic attack. Patients suffering from these attacks self-perceive a lack of control.
Panic attacks, however, are not limited to panic disorder. They can occur alongside other anxiety, mood, psychotic, substance use, and even medical disorders. Panic attacks can be associated with increased symptom severity of various disorders, suicidal ideation and behavior, and diminished treatment response in patients with concomitant anxiety and mental disorders.
Making an accurate diagnosis of panic disorder is not possible without a thorough understanding of what constitutes panic attacks. It is important to differentiate symptoms experienced during or in association with an actual alarm situation, such as a physical threat, from a true panic attack. According to DSM V (Fifth Edition) criteria, at least one panic attack must be followed by one month or more of persistent concern over having more attacks, worry about the consequences of the attacks, or maladaptive behavior such as avoidance of work or school activities. Although panic attacks may originate from the direct effects of substance use, medications, or a general medical condition like hyperthyroidism or vestibular dysfunction, they must not derive solely from these.
Panic disorder is not diagnosed when the symptoms are attributable to another disorder. For example, when panic attacks occur in the presence of a social anxiety disorder in which the attacks are triggered by social situations like public speaking, this is not considered a panic disorder. Certain culturally specific symptoms such as neck soreness or uncontrollable crying are not considered core symptoms of a panic attack.
For patients with panic disorder, the fear and anxiety symptoms that they experience primarily manifest themselves in a physical manner as opposed to a cognitive one. This is a distinctive finding.
Multiple theories and models exist which speak to the possible etiology. Most indicate the potential role of chemical imbalance as a major factor, including abnormalities in gamma-aminobutyric acid, cortisol, and serotonin. Additional studies have also implicated genetic factors as significant contributors. There is believed to be some genetic vulnerability.
Panic disorder has a relatively high lifetime prevalence, ranking behind only social anxiety disorder, posttraumatic stress disorder, and generalized anxiety disorder. Notably, patients suffering from panic disorder have much higher lifetime rates of cardiovascular, respiratory, gastrointestinal, and other medical problems compared to the general population. European Americans are more likely to suffer from panic disorder than African Americans, Asian Americans, or Latinos. Females are more affected than men. Panic disorder peaks in adolescense and early adulthood, with low prevalence in children below age 14 and another decline in later adulthood. 
Many neurotransmitters and peptides within the central nervous system appear to play a major role in the physical manifestations. Results of brain imaging studies have shown characteristic changes, including increased flow and receptor activity, in specific geographic regions including the limbic and frontal region. The amygdala is proposed as the main area of dysfunction. From a pathophysiological and psychological standpoint, medical illness and panic disorder are highly correlated.
There are two main theories which attempt to explain why patients are more likely to experience panic attacks. The first hypothesizes that susceptible patients lack the appropriate neurochemical mechanisms which would normally inhibit serotonin. The causes alterations in the fear network model of the autonomic nervous system. The second theorizes that a deficiency in endogenous opioids results in separation anxiety and an increased awareness to suffocation. 
The vast majority of patients with panic disorder complain of chest pain, palpitations, or dyspnea. Other common symptoms may include diaphoresis, tremor, a choking sensation, nausea, chills, paresthesias, or feelings of depersonalization. Because most patients complain of physical symptoms, they often inquire about alternative explanations of their symptoms not related to mental health. They frequently shy away from care by mental health professionals and instead seek reassurance from specialty medical consultants. A good example of this is a patient requesting a referral to a cardiologist for further evaluation. This is due in part because there is significant overlap between symptoms of panic disorder and those of acute cardiac events. It is important to remember that conditions such as irritable bowel syndrome, asthma, and vocal cord dysfunction also have many symptoms attributable to panic disorder.
Panic attacks in patients with panic disorder are more often characterized by severe dizziness, episodes of irregular breathing, and fears of losing control or "going crazy." Although physical examination of these patients is often normal, nonspecific findings may include elevated heart rate, elevated blood pressure, mildly elevated respiratory rate without increased work of breathing, mild tremors, and cool, diaphoretic skin to palpation.
There are no specific laboratory, radiographic, or other tests required to diagnose panic disorder. Be mindful, however, that health care providers often disregard the possibility of alternative diagnoses; in these cases, more extensive testing may be useful to exclude other medical conditions. Panic disorder occurs in the absence of another medical or psychiatric condition that can better explain the symptoms
The main approaches to the treatment of panic disorder include both psychological and pharmacological interventions.
Psychological interventions may consist of cognitive behavioral therapy. As an added benefit in patients with a panic disorder that also has concomitant comorbid medical conditions, there are components of their therapeutic regimens which may also secondarily improve their respective medical illnesses. Breathing training is a method of reducing panic symptomatology by utilizing capnometry biofeedback to decrease the number of episodes of hyperventilation. Several of these slow breathing techniques have been shown to benefit patients with asthma and hypertension.
Hyperventilation reduction can help patients with cardiovascular disease. Anxiety and stress-reduction techniques can lower adverse outcomes in cardiovascular illness by decreasing sympathetic activity. Relaxation and stress-reduction interventions can reduce anxiety and blood pressure.
Antidepressants and benzodiazepines are the mainstays of pharmacologic treatment. Among the different classes of antidepressants, selective serotonin reuptake inhibitors (SSRIs) are recommended over monoamine oxidase inhibitors and tricyclic antidepressants. SSRIs are considered first line treatment. Some authors have proposed that if first-line pharmacologic treatment is unsuccessful, consideration should be given to the use of antiepileptic drugs. There also exists a potential for atypical antipsychotics to be used in select circumstances. There should be careful weighing of risks vs benefits of benzodiazepine use. Treatment of any co-occuring anxiety, depressive, or substance use disorders should take precedent. 
Prognosis can be guarded. The presence of panic disorder without other psychopathology is rare. Most people will have recurrence of panic symptoms even after a period of having no attacks.
Panic disorder is associated with a higher risk of suicidal ideation. It is also associated with an increased risk of comorbid medical conditions and smoking.
There is no cure for panic disorder, and it can present in a number of ways, thus making the diagnosis difficult. The majority of patients with panic disorder present to the emergency room and hence the role of the nurse and emergency room physician cannot be overemphasized. The patient needs a thorough education on the disorder and understands that the symptoms are not life-threatening. The patient needs to be told about the different treatments available and the need for compliance. Plus, the pharmacist should caution the patient against the use of alcohol or recreational drugs. The patient should be taught to recognize the triggers and avoid them. Before starting any drug therapy, the patient should be informed about the side effects and benefits. In addition, the family should be educated in helping the patient overcome unrealistic fears and other behaviors. Finally, the patient should be educated on a healthy lifestyle by adopting good sleep hygiene, exercise, and a healthy diet. The patient should be advised against any herbal supplements without first speaking to the primary care provider. (Level V)
Panic disorder has no cure, and its course is unpredictable. The currently available pharmacological therapy and cognitive behavior therapy do work in about 80% of patients, but relapses are common. About 20% of patients continue to have symptoms that lead to a poor quality of life. About two third of treated patients have a good prognosis, achieving remissions for about six months at a time. If the trigger factors like stress, alcohol, financial problems, divorce are not controlled, the symptoms can create havoc. More important, there is a high risk of coronary artery disease in patients with panic disorder and the risk of sudden death is increased compared to the general population. Finally, the suicide rate is much higher in patients with panic disorder. There is a high association of social, occupational, and phsyical disability caused by panic disorder. (Level V)
|||Berenz EC,York TP,Bing-Canar H,Amstadter AB,Mezuk B,Gardner CO,Roberson-Nay R, Time course of panic disorder and posttraumatic stress disorder onsets. Social psychiatry and psychiatric epidemiology. 2018 Jul 12 [PubMed PMID: 30003310]|
|||Indranada AM,Mullen SA,Duncan R,Berlowitz DJ,Kanaan RAA, The association of panic and hyperventilation with psychogenic non-epileptic seizures: A systematic review and meta-analysis. Seizure. 2018 Jul [PubMed PMID: 29787922]|
|||Perna G,Caldirola D, Is panic disorder a disorder of physical fitness? A heuristic proposal. F1000Research. 2018 [PubMed PMID: 29623195]|
|||Sivolap YP, [Panic disorder: clinical phenomena and treatment options]. Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova. 2017 [PubMed PMID: 28617392]|
|||Farris SG,Robinson JD,Zvolensky MJ,Hogan J,Rabius V,Cinciripini PM,Karam-Hage M,Blalock JA, Panic attacks and smoking cessation among cancer patients receiving smoking cessation treatment. Addictive behaviors. 2016 Oct [PubMed PMID: 27235990]|
|||Foldes-Busque G,Fleet RP,Denis I,Poitras J,Chauny JM,Diodati JG,Marchand A, Nonfearful Panic Attacks in Patients With Noncardiac Chest Pain. Psychosomatics. 2015 Sep-Oct [PubMed PMID: 25583556]|
|||Lai CH, Fear Network Model in Panic Disorder: The Past and the Future. Psychiatry investigation. 2018 Sep 5 [PubMed PMID: 30176707]|
|||Quagliato LA,Freire RC,Nardi AE, Risks and benefits of medications for panic disorder: a comparison of SSRIs and benzodiazepines. Expert opinion on drug safety. 2018 Mar [PubMed PMID: 29357714]|
|||Blackwelder R,Bragg S, Anxiety disorders: A blended treatment approach. International journal of psychiatry in medicine. 2016 [PubMed PMID: 26936807]|
|||Ströhle A,Fydrich T, [Anxiety disorders: which psychotherapy for whom?] Der Nervenarzt. 2018 Mar [PubMed PMID: 29383412]|
|||Tanguay Bernard MM,Luc M,Carrier JD,Fournier L,Duhoux A,Côté E,Lessard O,Gibeault C,Bocti C,Roberge P, Patterns of benzodiazepines use in primary care adults with anxiety disorders. Heliyon. 2018 Jul [PubMed PMID: 29998202]|
|||Thibaut F, Anxiety disorders: a review of current literature. Dialogues in clinical neuroscience. 2017 Jun [PubMed PMID: 28867933]|
|||Legey S,Aquino F,Lamego MK,Paes F,Nardi AE,Neto GM,Mura G,Sancassiani F,Rocha N,Murillo-Rodriguez E,Machado S, Relationship Among Physical Activity Level, Mood and Anxiety States and Quality of Life in Physical Education Students. Clinical practice and epidemiology in mental health : CP [PubMed PMID: 29081825]|
|||Spijker J,van Vliet IM,Meeuwissen JA,van Balkom AJ, [Update of the multidisciplinary guidelines for anxiety and depression]. Tijdschrift voor psychiatrie. 2010 [PubMed PMID: 20931485]|
|||Apolinário-Hagen J, Internet-Delivered Psychological Treatment Options for Panic Disorder: A Review on Their Efficacy and Acceptability. Psychiatry investigation. 2018 Aug 20 [PubMed PMID: 30122031]|
|||Caldirola D,Alciati A,Riva A,Perna G, Are there advances in pharmacotherapy for panic disorder? A systematic review of the past five years. Expert opinion on pharmacotherapy. 2018 Aug [PubMed PMID: 30063164]|
|||Schwartz RA,Chambless DL,McCarthy KS,Milrod B,Barber JP, Client resistance predicts outcomes in cognitive-behavioral therapy for panic disorder. Psychotherapy research : journal of the Society for Psychotherapy Research. 2018 Jul 26 [PubMed PMID: 30049247]|
|||2016 Jun; [PubMed PMID: 30199184]|
|||Santos M,D'Amico D,Spadoni O,Amador-Arjona A,Stork O,Dierssen M, Hippocampal hyperexcitability underlies enhanced fear memories in TgNTRK3, a panic disorder mouse model. The Journal of neuroscience : the official journal of the Society for Neuroscience. 2013 Sep 18; [PubMed PMID: 24048855]|