BRITISH JOURNAL OF PSYCHIATRY (2006), 188, 432^438 Agoraphobia in adults: incidence and longitudinal Between 1993 and 1996, in the Baltimore ECA Follow-up Study, 88% of relationship with panic the original Baltimore cohort were traced, and 73% of those known to be alive were interviewed again using the DIS (nn¼1920).1920). O. JOSEPH BIENVENU, CHIADI U. ONYIKE, MURRAY B. STEIN, The survey method is described in detail LI-SHIUN CHEN, JACK SAMUELS, GERALD NESTADT and WILLIAM W. EATON elsewhere (Eaton et aletal, 1997). Briefly, the same survey procedures were used as in 1981. The interview was augmented with a life chart, in order to assist recall over the follow-up period. Mortality in the inter- vening 13 years was substantial as a result Background Theories regarding how The DSM–IV implies that agoraphobia is of the high proportion of elderly respon- spontaneous panic and agoraphobia relate almost always a consequence of sponta- dents originally sampled at this site. neous panic attacks (American Psychiatric Neither baseline phobias nor panic disorder are based mostly on cross-sectional Association, 1994, 2000). Recent editions were significant predictors of loss to and/or clinic data. of the DSM have been influenced by the follow-up or refusal to participate in the work of Klein (1980) and others, whose follow-up study, although phobias were Aims Todetermine how spontaneous patients usually reported that their agora- weakly predictive of mortality between panic and agoraphobia relate longitu- phobic symptoms followed unexpected interview waves (Badawi et aletal, 1999).,1999). dinally,anddinally, and to estimate the incidence rate spells of panic. Although epidemiological A subset of the 1920 participants in the of and other possible risk factors for studies found many people with agora- Baltimore ECA Follow-up Study was first-onset agoraphobia, using a general phobia but no history of panic, typical additionally interviewed by psychiatrists epidemiological methods, employing fully ((nn¼816). Individuals were selected for this population cohort. structured non-clinician interviews, were interview mainly if they showed evidence suspect (Horwath et aletal, 1993). Also, of Axis I psychopathology (especially with MethodMethod A sample of1920 adultsin east although retrospective investigations found the DIS) in 1981 and/or in the Follow-up BaltimorewereBaltimorewereassessedin1981^1982 assessedin1981^1982 and that agoraphobic symptoms preceded panic Study, although about a quarter were the mid-1990s with the Diagnostic Inter- in some patients with both conditions selected at random from the remaining view Schedule (DIS).Psychiatristdiagnoses (reviewed in Fava & Mangelli, 1999), the members of the sample (Samuels et aletal,, were made in a subset of the sample at authors of DSM–IV were concerned about 2002). A total of 816 persons participated possible recall bias (Craske, 1996) given in the psychiatric evaluation, which follow-up (nn¼816).816). the absence of prospective longitudinal included the use of a semi-structured diag- ResultsResults Forty-one new cases of DIS/ studies such as the one reported here. We nostic instrument, the Schedule for Clinical sought to determine first, how spontaneous Assessment in Neuropsychiatry (SCAN; DSM ^ III ^ R agoraphobia were identified panic and agoraphobia relate longitudi- WingWing et aletal, 1990). Participants provided (about 2 per1000 person-years at risk). nally, and second, the incidence rate of informed consent for each interview, and As expected, baseline DIS/DSM^IIIpanic and other possible risk factors for first- the current study was approved by the disorderpredictedfirstincidenceofagora--disorderpredictedfirstincidenceofagora onset agoraphobia, using a longitudinally Johns Hopkins Medicine Institutional assessed general population cohort, Review Board 3. phobia (OR(ORphobia ¼12,95% CI 3.2^45), asdidas did with clinical reappraisal at follow-up to youngeryoungerage,femalegenderandother age, female gender and other assess effects of possible diagnostic phobias.Importantly,baselinephobias.Importantly, baseline agora- misclassification. Diagnostic interviews phobiawithout spontaneous panic attacks The version of the DIS used in the first two also predicted first incidence of panic dis- interview waves (1981 and 1982) included a general description of a phobia (‘such a order (OR(ORorder ¼3.9,95% CI1.8^8.4).Longitu- METHOD strong fear of something or some situation dinalrelationships between panic disorder SampleSample that [you] try to avoid it, even though and psychiatrist-confirmed agoraphobia The Epidemiologic Catchment Area (ECA) [you] know there is no real danger’), fol- were strong (panic before agoraphobia programme was completed in five centres lowed by screening questions about fears OR¼20,95% CI 2.3^180; agoraphobia in the USA from 1981 to 1982 (Regier etet of ‘tunnels or bridges’, ‘public transporta- alal, 1984). Trained non-clinician inter- tion (airplanes, buses, elevators)’, ‘crowds’, before panic OR¼16, 95% CI 3.2^78). viewers administered the National Institute ‘going out of the house alone’ and ‘being of Mental Health Diagnostic Interview alone’. If respondents acknowledged having Conclusions The implied one-way Schedule (DIS; Robins et aletal, 1981) to a any of these unreasonable fears that causalrelationship between spontaneous probabilistic sample of the adult population resulted in avoidance and ‘interfered with panic attacks and agoraphobia in DSM ^ IV in each centre at two points in time, (their lives) or activities a lot’, they were appearsappearsincorrect. incorrect. separated by a 1-year interval. In given DIS/DSM–III diagnoses of agora- Baltimore, the original sample included phobia (Boyd et aletal, 1985). As noted by Declaration of interest None. 3481 participants (Fig. 1). WeissmanWeissman et aletal (1986), the DIS did not 432 Downloaded from https://www.cambridge.org/core. 26 Sep 2021 at 20:36:29, subject to the Cambridge Core terms of use. AGORAPHOBIA:AGOR APHOBIA: INCIDENCE AND RELATION WITH PANIC (Rubio-Stipec et aletal, 1992). Seventeen respondents with incident DSM–III–R agoraphobia reported no disorder-level symptoms in the first wave but, at follow- up, reported the onset of their earliest related fears as before 1981. It should be noted that the DIS–III–R did not assess age at onset of associated symptoms or interference, so these respondents could have had agoraphobia-related fears without meeting full criteria for agoraphobia until the follow-up period. Consistent with this, we found that more than half of these individuals (9 out of 17) reported ‘sub- Fig. 11Fig. Overview of the Baltimore Epidemiologic Catchment Area (ECA) Study.DIS,Study. DIS, Diagnostic Interview threshold’ DIS/agoraphobia-related fears Schedule; SCAN, Schedules for Clinical Assessment in Neuropsychiatry. in 1981. An additional three people re- ported that both the onset and offset of address the DSM–III concept of agora- Psychiatrists made agoraphobia diag- their fears occurred before 1981. All 20 phobia as ‘fear of being in a place from noses according to DSM–III–R criteria, were considered incident cases (in effect, which escape might be impossible or diffi- using the SCAN. Agoraphobic fears were giving priority to the time of assessment cult in case of incapacitation’ (American grouped together, with the following six data and assuming errors in recall for the Psychiatric Association, 1980). probes: ‘being in a public place when alone, three respondents mentioned above). We The version of the DIS used from 1993 open spaces, empty streets’, ‘crowds, shops, conducted additional analyses in which to 1996 was modified to reflect the changes theatres – places with no easy exit’, these three cases were excluded, and there in diagnostic criteria in DSM–III–R ‘travelling alone – buses, trains, planes’, was no substantive difference in results. (American Psychiatric Association, 1987). ‘going out alone – being alone away from There were also slight differences in the Screening questions for agoraphobia read: home’, ‘collapsing while alone or with no screening questions for DIS/DSM–III–R help near’ and ‘being alone indoors’. The agoraphobia; that is, it was conceivable (a)(a)‘Some‘Some people have such an unreason- SCAN glossary describes agoraphobia as that participants with phobias of riding able fear of being in a crowd, anxiety related to being in such situations, in cars or trains were missed with the DIS/ travelling in buses, cars or trains, or lessened in the presence of a trusted com- DSM–III interview and incorrectly classi- crossing a bridge that they always get panion. The anxiety is related to difficulty fied as incident DIS/DSM–III–R cases. very upset in such a situation or avoid escaping quickly (feeling trapped) or leav- However, we found that incident cases of it altogether. Did you ever go through DIS/DSM–III–R agoraphobia respondents a period when being in such a situation ing without embarrassment, or fear of always frightened you badly?’ being incapacitated, with no help near. who endorsed items containing these fears Thus, psychiatrists administering the SCAN were, if anything, less likely to report onset (b)(b)‘Did‘Did you ever have such an unreason- assessed the nature of the fears, not just the before 1981, compared with those who en- ably strong fear of being alone away situations in which they occurred. dorsed items containing the same situations from home that you always got very in both interviews (further information upset in this situation, or you