<unk>  is believed to be due to a combination of genetic and environmental factors. The condition often runs in families, and stressful or traumatic events such as the death of a parent or being attacked may be a trigger. Research has uncovered a link between<unk>  and difficulties with spatial orientation. Individuals without<unk>  are able to maintain balance by combining information from their vestibular system, their visual system, and their proprioceptive sense. A disproportionate number of<unk> s have weak vestibular function and consequently rely more on visual or tactile signals. They may become disoriented when visual cues are sparse (as in wide-open spaces) or overwhelming (as in crowds). Likewise, they may be confused by sloping or irregular surfaces. In a virtual reality study,<unk> s showed impaired processing of changing audiovisual data in comparison with subjects without<unk> . Substance-induced Chronic use of tranquilizers and sleeping pills such as benzodiazepines has been linked to onset of<unk> . In 10 patients who had developed<unk>  during benzodiazepine dependence, symptoms abated within the first year of assisted withdrawal. Similarly, alcohol use disorders are associated with panic with or without<unk> ; this association may be due to the long-term effects of alcohol consumption causing a distortion in brain chemistry. Tobacco smoking has also been associated with the development and emergence of<unk> , often with panic disorder; it is uncertain how tobacco smoking results in anxiety-panic with or without<unk>  symptoms, but the direct effects of nicotine dependence or the effects of tobacco smoke on breathing have been suggested as possible causes. Self-medication or a combination of factors may also explain the association between tobacco smoking and<unk>  and panic. Attachment theory Some scholars have explained<unk>  as an attachment deficit, i.e., the temporary loss of the ability to tolerate spatial separations from a secure base. Recent empirical research has also linked attachment and spatial theories of<unk> . Spatial theory In the social sciences, a perceived clinical bias exists in<unk>  research. Branches of the social sciences, especially geography, have increasingly become interested in what may be thought of as a spatial phenomenon. One such approach links the development of<unk>  with modernity. Factors considered contributing to<unk>  within modernity are the ubiquity of cars and urbanization. These have helped develop the expansion of public space and the contraction of private space, thus creating in the minds of<unk> -prone people a tense, unbridgeable gulf between the two. Evolutionary psychology An evolutionary psychology view is that the more unusual primary<unk>  without panic attacks may be due to a different mechanism from<unk>  with panic attacks. Primary<unk>  without panic attacks may be a specific phobia explained by it once having been evolutionarily advantageous to avoid exposed, large, open spaces without cover or concealment.<unk>  with panic attacks may be an avoidance response secondary to the panic attacks, due to fear of the situations in which the panic attacks occurred.
Agoraphobia
Major depressive disorder
Coprophobia
Post-traumatic stress disorder
Acrophobia
Separation anxiety disorder
Apeirophobia
Psychopathy