Reprinted from: Panic and Phobias 2
Treatments and Variables Affecting Course and Outcome
Edited by Iver Hand and Hans-Ulrich Wittchen
Förcword by G.L.Klerman
Epilogue by I.M.Marks
Springer-Verlag Berlin Heidelberg New York London Paris Tokyo
1988 10. Panic Attacks in Nonclinical Subjects
J. MARGRAF and A. EHLERS
Introduction community sample, a percentage higher than the combined frequencies of panic Sudden episodes of intense anxiety ac disorder and agoraphobia with panic at companied by a number of predominantly tacks. somatic symptoms (now usually ca!led If it is established that panic attacks are panic attacks) are the primary feature of not specific to people suffering fro m a the psychological disturbance termed specific disorder, il is importanl to study panic disorder in DSM-IIIR (APA 1987). the distribution of the phenornenon in This diagnosis was introduced based on the general population. There have been a the idea that panic attacks are a distinct first few attempts to approach this qucs type of anxicty in ncccl of thcir own tion using qucsti onnai rc scrccn ing diagnostic entity. However, recenl rnethods. Norton et al. (1985, 1986) initiat research has shown that panic attacks are ed this line of resea rc h. They fou nd not specific to panic disorder since thcy surprisingly high prevalenccs of panic also occu r 'icross a wide range of other attacks in noncl in ical subjects. About psychological disorders and evcn in non OllC-third of thcir lWü 5amplcs of under clinical populations. Barlow et al. ( 1985) gradt1atC students rc portcd having ex studied IOS patients with the DSM-111 pcrienccd at least one panic attack in thc diagnoses simple phobia. social phobia, past year. Thcy concludcd that panic generalized anxiety disorder, panic disor attacks orten occur in presumably normal der. agoraphobia with panic attacks. ob peoplc and thal thcse panic attacks sh:1re sessive-compulsive disorder. and major many similaritics with thosc or paticnts depressive episodes. The great majority of who have well-detincd panic disorders patients in each of these categories (at (Norton et al. 1985). least 83%) reported having experienced Aside from the quest ion of the distribu panic attJcks. A.l though the frequency of tion of" panic attacks in thc population, a!!acks var!ed across diagnoses. thcre there are at least two other important were only fe\\' differences in terms of the reasons to study panic attacks in nonclini symptom p represent a biased selection or the total such research by studies of the charac population or persons with panic attacks. teristics or nonclinical subjects with the Highly symptornatic inclividuals are morc same disturb:mce. likcly to scck treatrnent or tobe detected A second important reason to study in clinical scrcenings, an cfTcct Motulsky nonclinical panickers is related to the fact ( 1978) termed "asccrtainment bias." This that many of these people are infrequent bias incrcascs thc probability or pcrsons panickers. T hey experience fewer attacks with two disorders to be part of clinical than patients who seek treatment for the samples and thus may lead to mistaken full -blown syndrome. lnfrequent pan assumptions about the relationship be ickers may form the basic population out tween such disorders. For example, al of which some people wi ll continue to most all agoraphobic patients seen in develop the full clinical syndrome. If this clinical settings liave panic attacks (cf. is the case, infrequent panickers offer a Mendel and Klein 1969; Thycr and 1-iirnlc uniquc opportunity to study possibie 1985). In nonclinical community samples, vulnerability factors for panic att:icks. howcvcr. thc picturc looks quitc clilfcrcnt. Most of our currcnt etiological rcsearch Weissman et al. (1986) and Wittchen on panic attacks is correlational in the (1986) founcl that only a small percentage sense that groups of panic patients and or all subjccts meeting criteria for agora controls are compared in cross-sectional phobia also exhibitcd panic disorder (ran designs. True experimental designs would ging from 6% to 16% in thc various ECA for instance involve attempts to produce and MFS sitcs) and only anothcr 17% to panic disorder in previously ''normal" 50% showed limited panic symptorns in subjects. For obvious reasons such addition to agoraphohia. studics cannot bc conductcd. Thus, we Anothcr cxamplc for sarnpling hias is thc cannot makc fi rm statcments about causal postulatcd rclationship betwecn panic antecedcnts of the disorder. If infrequent disordcr and mitral valve prolapse (MVPJ. panickers are the basic popula tion for \Ve havc argucd elscwherc ( Margrnf et al.. panic disorder thcy should show 1vhatever 1988) Lhat the highcr prevalcncc of MVP diathesis for panic exists. In this case we obsen·ect in some studics of panic disor can assume that characteri stics of patients der patients rerrcsents a problem or co that are not found in infrequent p:mickers morbidity rathcr than a true functional are consequences rather tha n causes of relationship. If thc sampling bias inhercnt the disorder. On the other hand. infre in studying clinical samplcs is eliminated, quent panickers may represent a different thc association hctwccn p;1nic attacks ancl basic population than frequent panickers M\'P vanishcs. This was shown by I-lart (panic disorder patients). lt is possible man et al. ( 1982) and Dcvcrcux et al. that even though both groups show iden (1986). 11ho studied MVP patients and tical manifest symptoms (panic attacksJ their family 111embers who had not sought thcy suffer from different undcrlying treatment themseh·es. Family me111bers disturbances. In this case, infrequent with and without P.IVP were not different panickers should be studied to gain in from each othcr 11ith respect to numbcr sight into such a heterogeneity of the of panic attacks ancl othcr symptoms: panic atl::ick phenomenon. both groups were for less symptomatic than thl.! original samplc of MVP paticnts who hucl been refcrrecl to the clinic. Thus. Questionnaire Studies sampling bias ma1· strongly intluence the r.:sults or r.:se:m:h on clinical samplcs. lt Thc lirst studics of panic at tacks in prcs u is therefore irnportant to complcment mably normal populations were reported Panic Altads in Nonclinical Sub.i.:cts I05 by Norton et al. (1985, 1986). In their scale of thc POMS). litti guc (POMS), ;1nd initial sludy, 186 studcnts wcrc sc.:rccncd angcr (POMS). In c.:ontrast. there were no using the Hopkins Symptom Checklist difTerences compared to nonpanickers on (HSCL-90, Derogatis et al. 1973) and a any ofthe FSS-111 or FQ subscales (agora specially designed anxiely questionnaire phobia, social phobia, blood/injury asking for current levels of anxiety as weil phobiil, aggression, animal phobia) or the as frequ ency and sym1:ito111s of panic · POMS scales activity and confusion. Pan attacks. A striking 34.4% of lhe subjects ickers and nonpanickers were similar in reported having had one or more panic the frequency of reported previous treac attacks in the past year, and 2.2% reported ments for any mental or physical disorder. having had at least threc atlacks in thc Similarly, thc two groups wcrc cornpar past 3 weeks. The symptoms reported lo able with respect to age, sex, or socioeco occur during these attacks were similar to nomic stalus. Panickers reported signifi the ones described by clinical samples of cantly more first-degrce relatives who had panic attack patients (ßarl ow et al. 1985; panic attacks. Margraf et al. 1987). The most severe As in the first study, the most severe symptoms were heart pounding, trcm symptoms of panic attacks were palpita bling, sweating, tlushing, and dizziness. tions, trembling, sweating, clizziness. and Subjects describing at least one panic hot/c.:olc.J Oashes. Other characceristics of attack in the anxiety questionnaire scored panic attacks included a sucldcn onset in significantly higher than those withoul thc majority of cases (59% unclcr 10 min). attacks on the HSCL-90 subscales anxiety, an average of eight DSM-111 symptoms. phobic.: anxiety, dcprcssion. intcrpcrsonal anc.J a widc variety or situat ional contcxts sensitivity, somatization. and angcr/hos in which attacks occurred. especially tility. There were no significant difTer social Situations. Thc grcat majority or ences with respec.:t to obsessive-c.:ompul panickers reported havi ng expericnccd at siveness. psychoticism, paranoid ideation, least OllC life Stressor at thc onse t of thc ir or sleep difliculties. panic attacks. Most frequently mentioned In a second study, Norton et al. (1986) wcrc dini c.:ult ies at work, fomily c.:rises, screened 256 students with a refin ed and loss of a significant other. Subjects version ot· their questionnaire. now who experienced some unpredictable at termed th e Panic Attack Questionnairc tacks were different from those who (PAQ). Suhjects also complctcd thc S1;11c cxpcricnc.:cd only prcdic.:tablc atlac.: ks on 9 Trait Anxiety Jnventory (ST AL Spiel out of 40 comparisons. Those subjects berge r et al. 1970), the Beck Depression with unpredic.:table attacks reportcd more Inventory (BOI, Beck et al. 1961). and the attacks in more difTerent situations. as Profile of i\lood Stares (POMS. McNair et weil as more severe feelings of unrealit y al. 1981). In :iddition, subjects were either and tachycardia. gi\·cn thc Fear Survey Schedule (FSS-111, Together. these studies show that panic Arrindell 1980) or the Fear Question naire attacks may occur in more pcrsons than (fQ. Marks and Math ews 1979). Very previously assumccl and that suhjccts \\'ho similarly lO Lhe first SlUdy, 35.9% oi' thc havc panic attacks rcport 111orc psychop;1- sampk reported having experienced at thology than do nonpanickcrs. In add i least one panic altack in the past year. and ti on. the panic attacks experienced by 3.lt'O reponed having had at least three noncli nical panickers an d patients wi th attacks in the past 3 weeks. Panickers anxiety disorders arc \ery similar. \V hile scored significantly hi gher on state ancl thesc studies have yielded some l'ascinat traic :.1nxie1y (STA I, anxicty scale of thc ing clala and initiated an imponant line or PO~IS). depression (BOI, depression researc h, they also pose some ne\\ chal- 106 J. \largrar and A. Ehlcrs !enges. A tlrst problem is to establish the Panic disorder subjects showed more reliability and validity of the PAQ as EMG and SCL reactivity to the two compared to standard structured inter imagcry tasks, in frcquent pa nickers more view diagnoses. Norton et al. (1986) EMG and SCL reactivity to paced arith rcport ed that 22 out of 24 cases, previous metic. There were no ditTerences in heart ly identified as nonclinical panickers by rate reactivity or on the thought-listing the PAQ. also met DSM-JII criteria for measure. With respect to panic symp panic. attacks in a structured interview. toms, panic disorder subjects scored signi However, they did not give information as ficantly higher on four and infrequent to what interview was used, whether panickers scored higher on six out of 52 interviewers were blind to the qucstion comparisons. naire results, and the reliability of their Sandler et al. (1987) reported a compari interview and questionnaire methods. A son of nonclinical panickers and control second challenge is to go beyond mere subjects withoL1t panic attacks. Eighty questionnairc asscssmcnt of psychopa subjccts were recruited through screening thology and to comparc nondinical pan or collegc studcnts with a panic at tack ickers. clinical panickcrs. and normal questionnaire. Subsamples included fre controls 011 psychophysiological variables quent panickcrs, infrequcnt panickcrs. or the response to strcssors. More recent and panic-free controls. Cardiovascular studies hc.m:~ atternpted to addrcss these reactivity to a psychological (challenge issues. reaction time task) and a physical (cy cling) Stress task was assessed by measur ing heart rate and blood pressure at Laboratory studics intervals before. during, and after the tasks. All of the measures showed pro 13cck and Scolt ( 1987) comparcd ten gressive dcclincs during thc prctask basc subjects who had panic disordcr with ten linc pcriods. increases during the stress infrequent panickcrs. All subjccts were tests. and declines during the post-task recruited from thc community using rccovery phases. There were no differ media study. This is in contrast to the consislenl Tahlc 1. Odinitiun or a pani1.: alla1.:k giv1:11 in the and strong differences on several of the vcrsion or the panic allack qucstionnairc used in questionnaire measures in the two Nor thc Gcrman studics ton studies. We have recently conducted A p:111ic attack (anxiety attack) is a discrete period two studi es rrying to combine question of suddcn onsct of intcnsc apprl'ltcnsion, fcar, or naire and laboratory measures in a com tcrror, oftcn ;1ssociated with fcc lings ofimpending parison of nonclinical panickers and con doom. Thc following symptoms may be ex pericnccd: trols. Racing. f11Jl111 1. To rcrlicate thc Norton et al. (1985. 1986) lindings using a Gcrman translation or their Figure 1 gives an overview of"the studies. PAQ Each study consisted or three phascs. 2. To determinc the reliability and validity or thc First, a !arge group of undcrgraduate qucstionnairc S(rccning mcthod ;is comparcd students was screcncd using our German to a stand:ird structurcd interview approad1 translation of thc P/\Q. Thc dclinition of 3. To comparc nonclinical panickcrs anc.J rnntrols on a 4ucstionnairc battery and a psyd10physiu a panic attad givcn to thc suhjccts is logical laborJtory assessment shown in Table 1. STUDY l STUDY 2 sc~ee~· r; ~ AO N• 170 N•; 36 ( Pente Al~!C" ~es~1ortne1re. Jnoergraouate stuce~:s t<>rt~ •: ol · 9861 unoergraouat e stuaenc s +1 re l1 a:)l l1 ly ·a11na· 1n terv •,;ws. SCID N•43 s:va'I {Stn:cti.;r e-J Cllr ·\:)' l l"J~ erv t ew 1 aoout SO~ oan1ckers. for DSM . So1tze-.l. "' •!11011" 1986) sor. co~trol s oy PAO re!1ao11 1ty · e1:~0 · cc:n;ar1son N•43 N•SI s:~:y ~uesuonna !r ~ :attery, SC ID IPAO Jan1ckers SC IO/ PAO par.1c~ers osyc~oonys : : 1091ca 1 vs contro ls vs controls taooratory assessment Fi::. 1. Q,·en i.:" of thc tvlarburg and T iibingcn studies uf pani' :lltads in nondink:il subj.:(ls 108 J. i\largraf und J\. Ehlcrs In phase two, we selecled subsamples of Information about the occurrence, num PAQ determined panickers and nonpani ber, and intensity of attacks as weil as ckers or "controls" (about 50% each) stress at the onset of panic, avoidance using slrict critcria (panickers: reporting behavior, ancl fami ly history was gi ve n at least one spontaneous attack, at least rel iably. In contrast, subjects were not four sympto111s, attacks not only in social able to give reliable information about situations: controls: no attacks or anxiety whether they had ever experi_e_nced un ex symptoms). We then conducted blind pected ("spontaneous") attacks, panicked diagnostic interviews to determine th e only in social situations, or experienced agreement between the interview and most of their symptoms within 10 min. questionnaire methods. The interview Table 3 compares the number of subjects was a Gerrnan translati on of the Struc reporting panic attacks on the PAQ in our tu red Clinical In terview for DSM (SCID) two studies with the numbers reported by hy Spitzer and Williams (1986). In the Norton et al. (1985, 1986). The mean ages third phasc. subjccts mecting bolh PAQ or our samplcs were 24 (study 1) ancl 25 and SCID criteria for panic attacks ("non years (study 2), while 69% (study l) and clinical panickers") and controls were 65% (study 2) of all subjects were female. compared using an extensive question While we found a somewhat higher naire battery and a psychophysiological percentage of panickers for the past year, laboratory asscssment involving a base resul ts for the past 3 weeks close ly rcsem line and a hyperventilation task. In addi bl e those of Norton et al. (1985, 1986). tion. two substudies assessed the retcst Thus, their finding of a high percentage of reliabil ity of the PAQ and th e interrater nonclinical panickers is replicated using reliabilit~ · of the SCID in our hands. In the questionnaire method. However. thc foll owi ng. wc will prcscnt thc rcsults whcn using th c structurcd interview ap or thc prel i111inary analyses conducted so proach, a difTerent picture emerge. We far. found that only 12 out of 23 (study L The retest re li abi lity ofthe PAQ provecl to Marburg) and 15 out of 29 (s tudy 2. Tübin• be generally good. Sim ilarly, thc intcrrat gen) PAQ-determined pani ckers also met er reliability of thc SCID in our hands was SCID criteria for panic attacks. \Vhile we good. Table 2 summarizcs the resulls of thus had a high rate of false positives. the re test reliabi lit y study. there were only a few false negatives: Tahlc 2. Rc1c•;t.rcliabili11· or thc Pa nie :\ttack Qucstionnairc (samplc si zc: II= 39. retest int.:rv:il l.J-28 days with :1 rncan or 20 days) ltcm (llf gf E1·c r h:td p:1111c ;1ltack 0.80 Kappa E1·cr hau .3 :irtacks in 3 wccks 0.80 Kappa E"er worri Strc·s~ .11 llll<,'I or panic (8 ilcllls) 0.67 - 1.0 Kappa ·\gc or on Tablc 3. Frequency of panic auacks dcterminctl by lhc Panic Allack Questionnairc (pcrccnt or all sub jects) Studr 1: S1udy 2: Norton el al. Marburg Tübingen 1985 1986 (11 = 170) (11 = 136) (11 = 186) (11 = 256) Panickers 46 59 34 36 (last yearJ Panickers 21 29 24 23 (last 3 weeksJ Three atlacks 12 15.5 * * in 3 weeks (liferimeJ Threc auack.s in 2 2 3 last 3 weeks • These results were not rcportetl by Norton et al. pooled across both studies on ly 4 out of King et al. 1986), state-trait anxiety inven 42 PAQ nonpanickers met SCID criteria tory (STAl, Sp iel berger et al. 1970. trai t for panic. Overall rates of agreement were form), 13eck Depression lnventory (BOI. as low as 74°/o and 65% (kappa: 0.50 and Bcck et al. 1981), and the Mobility lnven 0.32, studies 1 and 2, respectively). A post tory (MI, Chamblcss et al. 1985). hoc analysis of those subjccts who ind icat Thc different qucstionnaircs use very ed panic attacks on the PAQ, but dicJ not different scales. For a standardized pre meet SCID criteria, revealed that dis sentation, we computed thc difference agreement was not of a pure "chance" bctween the mcans of ranickers and nature. Rather. it secmcd that thcsc folse controls cJividcd by thc standarcJ c.Jcviation positives reported milder variants of the of the control group. The bars in Fig. 2 same rhenomenon (cf. thc conccpt of thus indicate the di!Tcrencc hetween the limitecJ symptom attacks in IJSM-Il!R) two groups in units ur lhe stantlarcJ cJevia and that the interview had a morc con tion of the controls. The upper part of servati\·e cut-off bctwcen panic and non Fig. 2 shows those scales 011 which the panic. two groups di!Tered signillcantly ( P < The comparison of nonclinical panickers 0.05), the lower part scales without sign iti (P ..\Q and SCI D criteria) and controls on cant dilferences. lt is important to note the questionnaire battery yielded a num that qucstionnaires mcasuring s i mil~1r b.:r or pronounccd dilTerenc.:cs. Sincc constructs also yiclckd similar rcsulls. study 2 (Tübingen) used a more compre Thcrcf'urc. such scaks wc re groupec.J hensiYc battery. the pattern of'its rcsults is together. shown in Fig. 2. Thc rcsults ol' stucJy 1 Nonclinic.:;tl panickcrs rcportcd cunsillcra were generally similar. The question bly higher levels of phobophobia. ago naires used in study 2 werc the Panic and raphobic kars (but not avoidance beha Agoraphobia Profile (PAP, cf. Margraf vior). somatization. anxiousness. depres and Ehlers 1987), Fear Survey Schedulc sivencss. and injury phobia than nonpani (FSS. Arrindell 1980). Symptom Chcck ckers of' comparabk agc, sex. and socioe list-90 (SCL. Derogatis 1977), Sclf'-rcport conornic background. 01· the two depres ln\'entory of somatic symptoms (SISS. sion scales. thc BOI that locusses more on 110 J. Margraf' and A. Ehlcrs Slgn!rlcant Olfferences 2 stanoara oevlattoos or control grovP - PAP F5S 5CL 5155 5CL 5155 5CL ST Al BOI SCL SCL FS5 pnobo agora- somatlzatlon anxlousness depresston psycno- lnjury pnobla pl\Oblc tlclsm pllOt>la rears No Slgnlflcant Olfferences 2 stanoarc aevlattons or control grau~ 0 MI PAP FSS SC1. PAP fS.S SCt. PAP SCl FS.S $ISS PAP avolaance soc1a1 host1 11 ty separa- otner varlat>les anxlety aggresslon tlon anxlely Fii-!. 2. Cumparison of rianickcrs and controls using a qucstionnaire battery (study 2. Tübingen). The l•on rcrr.: Anxlety Rating (0- 10) -II- Noncllnical Panlcl HV: hyper.ienttlatlon baseline HV posl 18 -,------, 54 Panlc Symptoms State Anxl ety 16 52 (0-18) 50 (20-80] 14 48 12 46 10 44 8 42 6 40 38 4 36 2 34 0 ~--.-----...,.....----....--' 32 oasel 1ne HV posl oase11ne HV post 11 110 10 Control Symptom5 Heart Rate 9 (0-11) (bpm) 100 8 7 90 6 5 80 4 3 2 70 1 o.L.-~O----~=-=--=-=-=-=-=--~~~====~o~__J basel 1ne HV post baseline HV post Fi~. 3. Sc!ected rcsults of thc 11S)'chophysiologic;il laboratory assessment in study J (~brburgl. Shown :1rc sclf·r:ucd an:-;icty (on a 0-10 scalcl. numbcr of panic symrHoms (on a list of 18 symptomsl. state ;111 '\icty 3 ----- Nonclinical Panicl HV: hyperventi lat ion 0 ~-r---.---.---.---.---.--' base l ine HV 18...------~ 54~------52 Slate Anxiety 16 Panic Symptoms CO- 18) 50 (20-80) 14 48 12 46 10 44 8 42 40 6 38 4 36 2 34 0 ~--,-----.-----.--...... J 32...._-..-----..-----..-----' basel ine hypervent l lat Ion baseline hypervent1lat1on II ...------. 1 10 T------, 1o Contra 1 Symptoms Hearl Rate g (0-11) 100 (bpm) 8 7 go 6 5 4 80~ 3 70 ~~ o~--.------T-----r-~ baseline hypervenli lalion basel tne HV fig . .J. Sde..:tcd rcsults of the psychophysiological laborawry assessmcnt in study 2 ( fübing..:11). Slww11 are the same 1·anables :is in Fig. 3 du ring a 12-min basclinc and a 2-min hypcr\'cntilation test (60 .:yclcs per minl. For the hyperventilation pmadigm. self-report mcasurcs werc takcn immcdiatcly heforc anti aftcr hypcr\'cn: i:~ tion. hcart rates wcrc c:!lculatcd l'rom thc EKG imm.:diatcly h..:l(>rc allll d11ri11.~ thc: last 20 s of hyper\'en:ilacion. Black squares represent panickcrs. 011e11 s1111arcs reprcscnt con trols possible to de\·elop f uture forms of the nosis of panic in DSM-llIR. The fact that PAQ that agree better with instruments information about the "spontant.:it(' and such as the SCID. lt is also possible that the rapidity of onset of panic altacks was the low agreement was due to the lad; or not givcn reliably raises doubt as to the reliability of .:enain criteria for the diag- usefulness of these critt!ria. ll4 J. :vlargrar and A. Ehlcrs What are nonclinical panickers like? researchers (e.g., Barlow 1986; Clark 1986; Thcrc arc a numhcr of variahlcs in thc Margraf et al. !986a, 1986b; van den Hout, scll~rcport domain thal difl'crcntialc non 1988) in showing a number or postulatcd clinical panickcrs from cont rols. These causal factors for the development of are primarily measures of phobophobia, panic (c.g., fear of anxiety symptoms. agoraphobic fears, somalization, anxious anxiety response to hyperventilation) to ness, and depression. The physio logical be present in this population. They are variables assessed so far as weil as reactiv not consistent with views that assume ity to laboratory stressors difTerentiate separation anxiety or active avoidance · much less weil or not at all between behavior as necessary an tecedents of panickers and controls in nonclinical panic attacks. samples. The most consistent ditTerence If we want to use these results to make found in our laboratory assessments were more causal statements about the deve lonicallr clcvatccl levels of sclf-rcportccl lopment of panic attacks, we need pros anxiety and symptoms. Reactivity to pcctive longitudinal studics. These stress tasks ditTerentiated only poorly and studies have to determine whether infre cardiovascular measures ditTerentiatcd quent panickers are the basic population not at all in our studies and in that of out of which some subjects go on to Sandler et al. (1987). Even the signiflcant develop the full-blown clinical picture of difTerences on laboratory parametcrs panic disorder or even agoraphobia with reach a magnitude of only about one panic attacks or whether the phenomenon Standard deviation (of the control group) of panic is heterogeneous, representing ancl arc thus much smallcr than so mc of different subgroups of underlying causes. thc qucstionnairc diffcrenccs. Eithcr possibility is of' high scientific and S..:veral or thc fcaturcs of nonclinical clinical intcrest. In the first case, we havc panickcrs havc previously been founcl in a fascinating opportunity to study possible clinical panic disorder patients (e.g., vulnerability factors in subjects at a high phobophobia. somatization, gcncral anx risk to develop panic disorder. In the iousness. dcprcssion). Howevcr. further second case. we may gain insights into studies arc necded that directly comparc difTcrential etiologies of panic attacks nonclinical and clinical samples. lt is an possibly connected to clinical outcome in open question whclhcr thc infrequent the long run. In addition, the longitudinal panickers stuclied by 13eck and Scott study of noncl inical panickers may give us (1987) rcprcscnl a clinical or a nonclinical information about possiblc factors pro popu lation since all subjects were tecting most of them from becoming recruited through media announcemcnts clinical "cases". We have recently started IOr pcopk with panic attack s. In our such a prospcctive longitudinal follow-up experience. infrequcnt panickers who study of infrequent panickers at the respond 10 such advertisements are more Clinical Research Unit ofthe Oepartment similar to self-selected clinical cases than of Psychology at Phil ipps University. On to noncli nical subjects rccruited from the whole. the studies presented in this community screenings. This could be one chapter il lustrate the usefulness of sup reason for the lack of ditTerences between plementing the usual study of clinical the two samples rerorted by 13eck and samples by investigating of panic attacks Scott (1987). in noncl inical subjects. The results of studics of nonclinical panickers are consistent with the psycho .-lck11011 1/edge111e11rs: Preparation of this physiologic:.11. cognitive. or psychological chapter was supported in part by German models of ranic proposcd by several Research Foundation grant Eh 97/1- 1. Panic J\ttacks in Nonclinical Subjects 115 Additional financial support by the structure interview. J\rch Gen Psychiatry Department of Psychology of Philipps 40: 1070-1075 University and the help of 1. Florin, G. Ehlers A. Margrafl, Roth WT (1986a) Experimen tal induction of panic attacks. In : Hand 1. Jakschik, W. Lutzenberger, K. Meisner, ß. 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