NATURE, VOL. 220. NOVEMBER 2. 1968

Schizophrenic Birth Order: the Last but One Position RESULTS of birth order studies on schizophrenics from the United States, Canada and Britain suggest an in- creased incidence of patients born late in the family1-'.

A recent study, however, concludes that there is "an accumulation of evidence that the birth order distribution of schizophrenics varies with family size"--schizophrenics are born late in large families and early in small familiesa. Part of the evidence referred to is the sample of Solomon and Nutta,lle which included a large number of small families of high social class and which showed an increased incidence of early born patients. This bimodal result was explained by separate class-dependent factors operating in the different sizes of family. It is the purpose of this communication to test a single-factor explanation.

I t is possible that the schizophre~~ic patient tends to occupy a certain position in relation to the end of t,he family rather than in relation to the beginning (a reverse ordinal position), so that the penultimate sib, for example. is born late in large families, while irl two-sib families it, is the first born. The hypothesis is that there is over- representation of the penultimate reverse ordinal positiorl in schizophrenic samples.

By collecting data frorn the literature, a very large sarnplc can be amassed. Five studies in thc literature report samples of schizophrerlics (total N = 3,482) in such a way that distribution of the reverse ordinal positions can be calculated. The expoctcd distribution is calculated by the Greenwood-Yule methodlo. Over-representatioll is calculated as t,he difference between the observed and expected distribution as a percentage of the expoctod distribution. Table 1 shows that there is no continuous increase in over-representation towards the end of the family. There is a peak of over-representation at t,hc last but one position-this is true consistently for a.ll five samples individually.

There are two samples of non-schizophrenic psychiatric patients reportod in the literature which allow a similar analysis-498 manic-depressives1 and 2,500 neurot~icsl1.

In this non-schizophrenic sample there is no over- representation of the last but one position. Table 3 shows the fit between tho schizophrenic sarnplc and the non- schizophrenic sample (family size dist,ribut,ion corrected to that of the schizophrcnic sample). The disparity be- t,weerl tho samples is clearly greatest at the last but ono position.

Table 1. DISTRIBUTIOT OF REVEKSE ORDINAL POSITIONS

Pcreentaw over-reprcs~ntiitim

itcvxsc ordinal Observed Exp(!cL~!(l Obsrrvcd-~Expccted p x i t i o n ~listribution distribution ( lixpcctcd

Last Last b11t one T.ast but two Last but three Rrst S

Table la . SAMPLES CONTRIBUTING TO TABLE 1

Study N Country R<'Ft3rrncc USA USA VSA

Table 2. DISTKIUtTION O F REVERSE O R I ) I P A I POSITIONS OF SON-SCHIZO- PHRENIC PATTESTR

lteverse ordinal Observed l2xpected Percentage ovcr- position distribution (listril~ntion representation

Last Last bnt one Last but two 1,ast bnt t h r e ~ Rest S

T a b i ~ 3. FIT BETWEEN THE SCHIZOPHRENIC AND SON-SCHIZOPHRENIC SAMPLES

Percentage Non- over-representation

Reverse ordinal Schizophrenic schizophrenic Schiz.-Non-schiz. position listribution distribution (

Non-schir (corrected) Laat Last but one Last but two Last but three Rest N

This new allalysls of already published data clearly indicates that the presence of one younger sib is associated with schizophrenia and can explain the anomalous results of Solomon and Nuttall without the irltrodrlction of social class factors.

One ordinal position is now identified with schizo- phrenia, so selection of these pat,icnts for further study will allow bctter understanding of what, if any, is the ~ ~ n i q u e psychological position of t,he schizophrenic in the farnil y.

Shcrlley Hospital, St Albans, Hert#fordshire.

R. I). HINSHELWOO~

Rcccived Augi~st. I , 1968.

Xalzberg, R., Social and Biological Aspects of Mewtul Disease (Uticir, New York, 1940).

Gregory, I., Brit. J . Preu. Soc. Med., 12, 42 (1958). Wahl, (:. W., Amer. J . Psychiat . , l lS, 201 (1956). Sohoolcr. C., Arch. Gen. Psychiat., 4 , 91 (1961).

CFarina, A., Rarry, H., and Garmeey, N., Arch. Oe?!. I'suchiol., 9. 224 (1 Q(i!3) \ - - - - , .

Gregory, I., Acta Genet., 9 , .54 (1959). ' C:ranvillc-(irossman, K. L., Brit. J . Psychial . , l l2, 1119 (1966).

Rarry, H., and Barry, H., Arch. Gen. Psychiat., 17, 435 (106i). *Solomon, L., and Nuttall.R., J . Nerv. Metft. U i s . , l l 4 , 37 (196;).

l o C:retsnwood, M., and Yulc, G. U., J. Rol/ul Stat. Sor~., 77, 179 ( I 91 4 ) "Norton, A, , Brit. J. Prez.. Soc. Med., 6 , 253 (1952).

Evaluation of Teratogenicity of Lysergic Acid Diethylamide THE concern about the psychological anti physiological effects of lysergic acid diethylamide (LSD) has naturally led to the desire for experimental rnodcls to study the spect,ra of effects suspected to be caused by LSD. Arnong t,Elo recent reports of its biological effects when pregnant animal rriodels are used, one involving rats is negative1, anotk1cr5s ambiguous because alt,hough stunted and still- births were reported with LSD at. 10 days post pi~rt.r~rn the offspring were l~nusually large, ~vnighing 44 46 g. Results with hamst,ers3 arc equivocal because of thc slrla.ll i~lcidence of nralforrnntions reported, and t,hose for mice are positive4.

This report describes an attempt t,o dcrnonstrate a teratogcnic response to LSD using pregnant mice and hamsters. In addition, secondary Syrian hamster cultures were examinod for growth alteration and for chro~nosomal abcrrat,ions in the presence of LSD. 'Delysid' (LSD-25) was obtained frorn the US National Tnst,it~~t~es of Health as a solution containing 0.1 mg/ml. of LSD tartrate (Sandoz, lot No. 65002). Immediately beforo use, further dilutions were made with Dulbecco's salt solut,ion which

also used for t,he control groups. Syrian hamsters from tho NIH breeding facilities, 9-11

weeks old and weighing approximately 100 g, wcro used. This species has responded to a wide variety of terato- gens5-'. They were irijected intraperitoneally during the time of greatest differentiation with a single dose of 10 pg (two animals), 100 yg (four anirnals), 200 yg (throe animals) or 300 yg (four animals) on days 6, 7 or 8 ; in one case,

NATURE. VOL. 220. NOVEMBER 2. 1968

Strain O.P.

Table 1.

LSD dose ( f ig)

ABNORMALITIES INDUCED BY LSD-25 INJECTED INTO PREGNANT MICE

No. of No. of litters with No. of females No. of progeny malformations malformations

repeatcd doses of 100 pg were given on days 7, 8 and 9. All pregna~lcies werc terminated on day 14.

Within the fourteen treated hamsters, 171 implantation sit.es were noted: 168 were live foetuses of which one had microphthalmia; three cases of resorptions were found. Animals treated with LSD did not vary statistically from control animals in weight changes of pregnant mothers, or in average litter weight or size; furthermore, no more resorbed foetuses occurrcd in animals which had been t'reated with LSD than in control animals. On rare occasions control animals do exhibit spontaneous exencephaly.

Neithcr 1.0 nor 20 pg of J>SD/ml. of Eagle's minimal esser~tial medium plus 10 per cent foetal calf scrum dtered the logarithmic growth of secondary Syrian hamster embryo cultures originally made from trypsin ized minced whole embryos 12-14 days old. After 24 or 48 h of exposure the cell counts were similar to those obtained in control cultures. Nor was any cvidence of chromosome breaks found in 274 colcemide arrested metaphases after 24, 48 or 72 h exposurc to 0.9 yg, 18 yg or 45 yg of LSD/ml. of culture medium, respect,ivcly.

NIH General Purpose and A/Cum mice (Table 1) weigh- ing approximately 31 and 25 g, respectively, were irljccted ititraperitoneally according to the schedule of Auerbach and Rugowski4. Further animals were given multiple irljectioris to enslire that the critical period (day 7) referred to by Auerbach had been properly covered. 'l'hc total amount received by each pregnant animal ranged from 0.5 pg to 30 pg. Mice werc killed on the rlevcrit,h or fourteenth day. Of 167 General Purpose mouse foet,uses examined from twenty-two treatcd mothers, no external rrlalformations were found and no ~tat~istical diffcrences 111 size or weight were noted between 167 foetuses obtaincd from mothers trcat,ed wit,h LSD and fifty-eight foetuses obtained from six mothers injccted wit,h salt solution. From fourteen pregnant A/Cum fernale mice treated with LSD, sevent,y-nino foetusos were obtaincd; six lit,t,crs had fifteen foetuses with abnormalities consisting of hare lip, cleft palate or micrognathia. Examination of sixt,y- six foetusos from ten females of the control group revealcd t,wo foct~ises (from one litter) with nbnormalities similar to the micc treated with LSD. No other difference between the two groups was observed.

The present investigation failed to dcmonst,mtc that, LSD is teratogenic for NIH Syrian hamsters and for general p~irposc mice. Although the negative results we obtained with the harnsters are statistically different from the positive results reported by Geber-rc interpret, them as being not esserlt,ially different. In t,he case of positive resillts one would expect a dose response relstion- ship and an increasc in abnormalities much higher than the va.riation from 5 to 8 per ccnt3 (average of less than one in each litter). I t would bc expected that with controlled conditions including known amounts of chcmi- cal, a genetically defined animal populat.ion, and defirlcd periods of maximum orgarlogenesis, ti positive teritto- logical response would be demonstrated by a grcater shift.

The res~llts of Auerbach and Rugowski4 with micc show a.n appreciable incidence of malformations (57 pcr cent). Abnormalities of a similar type normally occur in 10 per cent of the same colony. Thc ovcrsll frequency of rrlalformed foct,uses in our A/Cum mice was 19 per cent'.

No. of malformed animals mit.h any malformations!litter

The malformations in A mice werc similar to those which occur spontaneously in this st,rain. The doscs of LSD that gave teratogenic effccts are of the order of 25-1 , U ~ O times the average single human dose. The relatively lo\\- number of malformations obtained with large amounts of LSD may reflect potentiation of individual threshold differences for these malformations. Differences in threshold responscs for cleft palate have been reporid for C57Bl/6J mice8. There is evidence for strain specificity in the incidence of malformations produced by trypan blue in rats that varies from strain to strain9 and by thalid- ornide which produces malformations in A strain mice1" hut not in C57Bl/6J mice". Our results suggest no firm conclusions concerning the possible teratogenicity of LSD in rodents othcr than the possihle potentiation of threshold difference in some A rnicc.

Cytoge~let~ics and CyLology Section, Biology Branch, Etiology, National Cancer Institute, Rethesda, Maryland.

Received August 1, 1968.

' IVarkany, J., and Tnkacs, E., Science, 169, 731 (1968). Alexander, G. J., Miles, R. R., Gold, (:. M., a n d Alexander, R.iR.,Science,

157, 459 (1967). Gel)er, W. F., Science,l58, 265 (1967). Auerbach, R., and Rl~gowski, .T. A,, Science, 167, 1325 (1967). Fenn, V. I%., Lah. Invest., 14, 1500 (1965). Elis, J . , and DiPaolo, J. A,, Arch. Pafhol., 83, 53 (1967). DiPaolo, J. A,, and Elis, J., (?a:nltcer Res., 27, 1696 (1967). Trnsler, D. G., Teratolog)j, 1, 33 (1968). Gllnl~erg, F. I.., Anat. Rec., 130, 310 (1958).

'ODiPaolo, J. A,, Gatzek, II., and Pickren, J. , Anal. Rec., 149, 149 (1961). " Tr;~sl?r, D. G., a n d Fr:~ser, B..C., qlloted by Fraser, F. C . , Second Intenf.

COI I .~ . Congenital Malformnlzons, 277 (New Ynrk City, 1963).

Electroencephalographic Alerting Sites of d-Amphetamine and 2,s-Dimethoxy-4-methyl- amphetamine THE amphetamine derivative, 2,5-dimethoxy-4-metll>-1- amphetamine (STP), is a new psychotomimctic dricg, considered to bc about one hundred times more powerful than mescaline in producing psychedelic symptoms i l l

human beings1. Wo have made an eloctroenccphalographic (EEG) analysis to determine t,he sites of action in rabbit. brain of d-amphetamine and STP. I t has been shown t,llilt nor)-psychotomimetic congeners provoke EEG alcrt,iilp from the midbrain level, while their psychoto~nirrlctic congeners such as LSD, psilocirl and mescaline cans(. alerting by their action at a lower level in the bm.irl- tern^-^.

Forty-one albino rabbits ranging from 2.2 to 3.0 kg were tracheot,omixed under ether and local nnaest,hesia, cumrized and artificially respired. To record the clcctric~il