A longitudinal study of general practitioner consultations for psychiatric disorders in adolescence

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1 Psychological Medicine, 99,, Printed in Great Britain longitudinal study of general practitioner consultations for psychiatric disorders in adolescence NIGEL SMEETON, GREG WILKINSON, DVID SKUSE ND JOHN FRY From the Department of Public Health Medicine, Guy's Hospital; Department of Psychiatry, London Hospital Medical College; Department of Child Psychiatry, Institute of Child Health, London; and Beckenham, Kent SYNOPSIS Patterns of psychiatric diagnoses given during adolescence to a group of individuals continuously registered with a single general practitioner in South London over years were analysed first during 'early adolescence' and secondly during 'early adulthood'. Psychiatric diagnoses were found to be relatively common. Of the young adolescents who received a psychiatric diagnosis (almost one in ten of the group), 38 % received a psychiatric diagnosis as young adults compared with only 6 % of the remainder. Comorbidity was found to be very common - over 5 % of young adults with a diagnosis of depression also had a diagnosis of anxiety and phobic neuroses. Young people with problems of a psychological nature therefore deserve more attention, particularly from the primary care team. INTRODUCTION It is now well-established from the findings of the Second and Third National Morbidity Surveys (HMSO, 974, 979, 986) that psychiatric disorders are rarely recorded by general practitioners in young children but the likelihood of being given such a diagnosis increases rapidly through adolescence and into adulthood (Smeeton, 987). It is, therefore, of interest to quantify the extent to which the recording of a psychiatric diagnosis in 'early adolescence' by a general practitioner increases the likelihood of such a diagnosis being made in early adulthood and to investigate changes in the pattern of diagnoses made in the two periods. For this purpose longitudinal data which chart the progress of children from about ten years of age for at least ten years are required. The presence of psychiatric diagnoses should be recorded during 'early adolescence' and again during early adulthood. The general practitioner is perhaps best placed to care for patients with these problems as he or she is often involved with these patients since childhood and knows ' ddress for correspondence: Mr Nigel Smeeton, Department of Public Health Medicine, UMDS (Guy's Campus), London SE 9RT. 79 their background well. We have consultation data for a continuous -year period from a single general practice in South London from which over children who satisfied the above requirement were identified. METHOD In 957 a general practitioner (Dr Fry) compiled a case register of all 6346 patients then registered with him in his South London practice; 443 of them remained on his list for the next seven years (Cooper et al. 969) and 53 of them were still registered in 976 (Dunn & Skuse, 98). There were no major changes in his practice during the period. The general practitioner's detailed NHS records provided both a prospective design and a satisfactory level of reliability. The ability of the general practitioner to recognize psychiatric disorder among patients attending his surgery is evidenced by a study conducted by Skuse & Williams (984) which found his overall identification index, bias and accuracy to be -57, -7 and -39 respectively. These figures are very close to those found in comparable surveys of other practitioners and suggest that his ability to detect cases of psychiatric disorder is similar to that of other 4-

2 7 TV. Smeeton and others Year B Year FIG. I. Years of birth and periods of early adolescence and early adulthood for individuals included in the study. (B = year of birth; = year of assessment.) family doctors (Marks et al. 979). The patients who were studied were limited to those who had remained registered with the general practitioner. None of the sample was seen by a psychiatrist. Since the attrition was so great, it is worth considering whether the patients who remained registered with Dr Fry were representative of the original group of patients. The proportion of males in the patients remaining was very stable over the years; this was 48% in 957, 47-7 % in 963 and 47-5 % in 976. However, the age distribution changed considerably. Cooper et al. (969) reported that the rates of loss for different age groups differed widely. In their study, a conspicuously high rate of loss from causes other than death for the age group -3 was due, probably, to the high mobility of young adults. By 976, 75-5 % of the males and 83-4% of the females were over the age of 4 years. Hence, a disproportionate number of younger people (especially females) left the practice over the -year period. ge periods studied The patient records were coded on a year by year basis, so it was decided to define the first period (' early adolescence') from the commencement of the year containing the tenth birthday to the end of the year in which each individual became 4 (a period of five years). Therefore, only patients aged 9 or less at the beginning of 957 could be included in the study (see Fig. ). period of this length was required in order to obtain a reasonable number of subjects with a psychiatric diagnosis made by the general practitioner in 'early adolescence'. The second period ('early adulthood') ran from the commencement of the year in which the individual became 8 to the end of the following year (a period of two years). This shorter comparison period was chosen because complete information was available for these years on all subjects eligible for inclusion in the first period. From Fig. it can be seen that were the second period to be extended, information on the youngest would be incomplete. From the general practitioner records, for each of these individuals it was noted whether any psychiatric disorder had been diagnosed by the general practitioner during the first and second periods. These disorders were recorded in the terms of diagnostic categories which were chosen by the researchers (in 978) in consultation with Dr Fry and were intended to be compatible with Dr Fry's diagnostic habits. The possible diagnostic categories were depressive neurosis, anxiety and phobic neuroses, personality disorder, functional psychosis, druginduced psychoses and drug reactions, miscellaneous neurotic disorders and alcohol abuse and drug dependence. These had been chosen with a view to making diagnoses in the adult population attending, and consequently diagnoses more appropriate to childhood and adolescence, such as 'attention deficit disorder' and 'disorder of conduct' were not specifically noted in the records. logit model was fitted to the data (a linear model was fitted to the log of the odds of an

3 GP consultations for psychiatric disorders in adolescence 7 individual having a psychiatric diagnosis in early adulthood) using the GLIM statistical package (Baker & Nelder, 978). The independent variables were presence or absence of psychiatric diagnosis in 'early adolescence' (PSYCH), gender (SEX) and whether the individual was in a. younger cohort (-4 in 957) or an older cohort (5- in 957) (COHORT). The three possible first-order interactions and the single possible second-order interaction between variables were also studied. RESULTS There were 34 males (of mean age 4-6 years in 957) and females (of mean age 3-64 years in 957). This meant that on average the periods of interest for males preceded the periods of interest for females by one year. This shift is unlikely to Table. Psychiatric diagnoses given by the general practitioner to children in early adolescence and early adulthood* Diagnostic categories nxiety and phobic neuroses Depressive neurosis Personality disorder Functional psychosis Drug-induced psychoses and drug reactions Miscellaneous neurotic disorders t least one psychiatric diagnosis No psychiatric diagnosis Total Early adolescence g 6 5() 9(89) (6) 94 (94) Early adulthood 4 8(3) 6(87) 34 Patients could be given more than one diagnosis. Table. Parameter CONSTNT PSYCH SEX COHORT The logit model parameters Mean S.E P < < <5 NS 4 (4) 76 (76) Model fitted: log P/{\ -P) = CONSTNT+ PSYCH(Q +SEX- C + COHORT(*:), where P is the probability of a psychiatric diagnosis during early adulthood; / =, no psychiatric diagnosis in 'early adolescence', i =, psychiatric diagnosis; j =, male,j =, female; and k =, -4 in 957, k =, 5- in 957. have had any effect on the results and in any case could be adjusted for with the COHORT variable. Psychiatric diagnoses in 'early adolescence' and early adulthood The frequency of the psychiatric diagnoses made by the general practitioner in 'early adolescence' and early adulthood is shown in Table. For 'early adolescence', more males had a psychiatric diagnosis compared with females (6%). For the males, the most frequently used diagnostic category was ' miscellaneous neurotic disorders'; for the females, it was ' anxiety and phobic neuroses'. The individual frequencies in Table add up to more than the total number of individuals with a psychiatric diagnosis, as several were given more than one diagnosis during 'early adolescence'. with at least one psychiatric diagnosis had an average of -9 such diagnoses and similarly affected females had an average of -5 diagnoses. In general, this was due to the commoner diagnostic categories occurring together, although numbers are too small to make any definitive statements. In contrast to 'early adolescence', in early adulthood more females (4 %) had a psychiatric diagnosis than males (3%). For the females, the diagnoses were almost all specific neuroses. s far as males are concerned, the pattern is broadly similar to that for 'early adolescence', with depression and anxiety diagnoses somewhat more frequent and miscellaneous neurotic disorders dropping in frequency. similar pattern for co-morbidity was seen in early adulthood as in 'early adolescence'. with at least one psychiatric diagnosis had an average of such diagnoses and females had an average of -5 diagnoses. Of the males with a diagnosis in the category of depression, 75% also had a diagnosis in the category of anxiety and phobic neuroses, the corresponding figure for females being 48%. The logit model The findings from the logit model fitted by GLIM are presented in Table. The overall mean (CONSTNT), presence of an earlier psychiatric diagnosis (PSYCH) and gender (SEX) exerted statistically significant effects. The cohort effect was not statistically significant but there is some evidence from the data that the

4 7 N. Smeeton and others Table 3. Estimated probabilities of having a psychiatric diagnosis in early adulthood Cohort Younger (-4)* Older (5-)* Psychiatric diagnosis in early adolescence No * In 957. Yes younger cohort was more likely to receive a psychiatric diagnosis in early adulthood when the other two independent variables were taken into account. Table 3 shows the estimated probabilities of having a psychiatric disorder in early adulthood, using the simple logit model. These probabilities agree well with the observed data (G = 5-86, df = 4, P = -79). Nearly two-fifths (38%) of those with psychiatric diagnoses in ' early adolescence' received such a diagnosis in early adulthood, compared with only 6% of the remainder. Thus, the likelihood of a psychiatric diagnosis in early adulthood is two to three times greater if there is a psychiatric diagnosis in 'early adolescence'. were about 5% to 8% more likely than males to have a psychiatric diagnosis during early adulthood irrespective of previous psychiatric history. None of the interactions fitted in the logit models were significant, so the simple model involving only the main effects appears to explain the data adequately. limitation appears from the observation that the distribution of diagnoses in early adolescence is quite different from that obtained in either psychiatric epidemiological studies or clinical investigations. Conduct disorders which predominate in both these settings are not represented here at all. Such cases might be presumed to be included in the 'miscellaneous neurotic' group. Table 4 shows that when the individuals receiving a diagnosis of' miscellaneous neurosis' were reviewed in 99 and re-classified according to ICD-9 (WHO, 978) only one male received a diagnosis of hyperkinetic conduct disorder. The diagnostic categories chosen for use in this study reflected the general practitioner's diagnostic habits which may not have remained stable over a -year period. t the same time, there have been continuing developments in the classification and categorization of psychiatric disorders in childhood. In 965, when the data set was being recorded, Rutter stated that 'a generally acceptable classification of psychiatric disorders which occur in children is urgently needed and the lack of such a classification has been a severe obstacle to progress in child psychiatry' (Rutter, 965). Rutter et al. (973) showed that a multi-axial system of classification has important advantages in child psychiatry. Since then, the classifications elaborated in ICD- 9 (WHO, 978) and DSM-III-R (P, 987) have become widely available and these will be superseded by the revisions embodied in ICD- and DSM-IV in due course. Thus, while we fully acknowledge and accept the deficiencies of the system of classification adopted for use in this study {circa 979-8) this has to be viewed alongside the evolving ideas in this field. DISCUSSION The findings are unusual and of particular interest because they are based on general practitioner records maintained over a long time period. However, this advantage is accompanied by the disadvantage that the diagnoses in the later age period are not blind to those in earlier age periods; the diagnoses are necessarily based on limited, non-standardized data and are likely to have low diagnostic accuracy; the adult age period covered is short ( years); and data are missing on three quarters of the initial sample (as discussed above). n apparent diagnostic Table 4. Children in early adolescence with GP diagnosed miscellaneous neurotic disorder ICD-9* code Disorder Disturbance of emotions specific to childhood and adolescence: With anxiety and fearfulness With misery and unhappiness With sensitivity, shyness and social withdrawal Relationship problems Hyperkinetic syndrome of childhood Hyperkinetic conduct disorder * World Health Organization (978). f One female. Total 3 3t 4t 3

5 GP consultations for psychiatric disorders in adolescence 73 It was not possible to apply current standardized diagnostic criteria to these diagnoses nor to take account of subsequent developments in psychiatric nosology and classification in relation to childhood and adolescence. In so far as the predominant diagnoses were those of emotional disorder the findings are consistent with those of Garralda & Bailey (986 a, b). The paucity of conduct disorder in this study is not explicable and could conceivably be related to diagnostic habit, secular change, or variations in sociodemographic characteristics in different samples. It is possible that, if current diagnostic instruments and techniques had been available, the rates of disturbance identified in this study might well have been higher (or lower) and might have suggested greater continuity (or otherwise) of psychiatric disorders across the age spans considered here. The results demonstrate that psychiatric disorder diagnosed by a general practitioner in children during early adolescence increases the probability of a general practitioner diagnosed psychiatric disorder in early adulthood by a factor of two to three times. It could be argued that recognition of a disorder in the past may increase the likelihood of recognition in the future. While this is always a possibility, it should be noted that 38 % of those individuals who had a psychiatric diagnosis recorded in 'early adolescence' had no subsequent records in the period up to the end of 976. It is likely that the period of the study which we defined as early adolescence' included puberty, which is usually complete between -6 years in girls and 3-7 years in boys. Psychiatric disorders in adolescence (i.e. post pubertal) differ substantially from those of younger children, the pattern of emotional disorders in earlier childhood tending to be diffuse in form. Psychiatric disorders commencing in later adolescence are likely to be better differentiated, with a greater resemblance to adult neurotic conditions (Graham & Rutter, 985). This greater differentiation in diagnoses is clearly reflected in the data presented in the paper, with undifferentiated 'miscellaneous neurotic disorders' predominating in 'early adolescence' especially among males. There is a very clear trend towards more specific diagnostic categories among the females during early adulthood, and quite a sharp differentiation at that time between the more specific psychiatric diagnostic categories used in females, contrasted with a persistent relatively high proportion of 'miscellaneous neurotic disorders' diagnosed in males of the same age group. It may also be the case that the general practitioner was understandably reluctant to label young children with specific psychiatric diagnoses. dditionally, it may be that conditions in childhood are even harder to categorize than those occurring in later years (Jenkins et al. 988). In contrast to the extensive research interest in adult psychiatric morbidity in primary care there have been relatively few reports concerning childhood and adolescence (Giel et al. 98; Wilkinson, 985). Recently Garralda and Bailey (986 a, b, 987, 988) have reported that 3% of children between the ages of 7 and years of age attending general practitioners have psychiatric disorders. They found disturbance slightly more frequent in girls than in boys, and emotional disorder was the most common diagnosis (53 % ) ; followed by mixed emotional/ conduct disorder (5%); conduct disorder (4%); and other (8%). These disorders had been present for over years in 4 %; under 6 months in 8%; between and years in 4% and for 6 months to year in % (length of disorder was not established in 6%). In these studies psychiatric disorder was associated with psychological disadvantage (broken homes, the child had lived away from the family, family history of psychiatric disorder) and with current high levels of parental stress in relation to their children. Disturbed children tended to present with symptoms of anxiety, bed-wetting, hayfever, nose bleeds or scabies. Thus psychiatric disorder may be a relevant factor contributing to somatic consultation in this age group. We did not consider these issues as our data were insufficiently detailed. Other studies have also shown that about one in five adolescents in the community have had some kind of mental health problem of clinical significance, e.g. Offord et al. (987). This compares with a figure of one in eleven in our early adolescents and almost one in five in our young adults. In the recent survey of children aged -6 by Offord et al. the community prevalence rate was found to be 9% in males and % in females. Similar findings were

6 74 N. Smeeton and others obtained by McGee et al. (99) who studied a large sample of adolescents from a general population in Dunedin, New Zealand. The higher community prevalence rates referred to may have included children with conduct and other psychiatric disorders not diagnosed by the general practitioner in the present study since they were not considered (being recent diagnostic 'discoveries') or, more simply, missed diagnoses. McGee et al. (99) noted much co-morbidity of depression; about two-thirds of those with a depressive disorder had a coexistent conduct or anxiety disorder. This observation fits well with the findings on co-morbidity of the psychiatric diagnoses given to the sample studied in the course of our survey, especially during the second follow-up period in early adulthood when 75 % of males and 48 % of females with depression also received a diagnosis in the category of anxiety and phobic neuroses. Depressive disorders during adolescence have consistently been found to be far commoner among females (Jorm, 987). This was found with our sample as young adults but not as young adolescents. Change in the frequency of depressive conditions through adolescence is well known. For example, in the Isle of Wight longitudinal study of year olds there were over ten times as many with depression or depressive symptoms in the follow-up at 4-5 years (Rutter et al. 976). lso, the sex ratio of affective disorders changes during adolescence (as seen in our sample) from a male preponderance before puberty to a female preponderance in early adult life (Rutter et al. 986). We would expect that the extent of disorder diagnosed in the course of this investigation would be intermediate between the disorders of those referred to out-patient and in-patient facilities and those disorders discovered in the course of epidemiological surveys comprising largely non-referred children. Previous studies following up psychiatric disorders in adolescence have usually concerned themselves with samples of children treated for psychiatric disorder (Capes et al. 97; Warren, 965). From pooled data, it has been estimated that about 83 % of adolescents with emotional or neurotic problems improve as they grow into adulthood (Graham & Rutter, 985). Our data give no evidence of improvement; they do provide evidence of recurrence being of the order of 38 % (95 % C.I. -73, -589), based on a -year period. We would stress, however, that these data are not comparable to the findings from population studies as the young people in this study were a select group of geographically stable individuals. basic problem remains because of the small size of the group of young adolescents with a psychiatric diagnosis and hence a wide confidence interval. dolescent health problems tend to be neglected by health services and are a cause of substantial morbidity and mortality (with high rates of parasuicide, particularly among young women and high rates of suicide, particularly among young men). The present findings suggest that increased recognition and treatment of these problems is necessary and this should ideally be at the level of primary care. In consequence, general practitioners and the primary care team need specialist information, advice and practical help in how to identify and treat young people with these disorders more effectively. We thank Eileen ndrew for coding the data. The work was initiated by Professor Michael Shepherd at the General Practice Research Unit, London with the support of the Department of Health and Social Security. Mrs Joan Boucnik typed the several drafts of this manuscript. REFERENCES merican Psychiatric ssociation (987). Diagnostic and Statistical Manual of Mental Disorders (3rd edn. - Revised). M: Washington DC. Baker, R. J. & Nelder, J.. (978). The GUM System. NG: Oxford. Capes, M., Gould, E. & Townsend, M. (97). Stress in Youth. Oxford University Press: London. Cooper, B., Fry, J. & Kalton, G. (969). longitudinal study of psychiatric morbidity in a general practice population. British Journal of Preventive and Social Medicine 3, -7. Dunn, G. & Skuse, D. (98). The natural history of depression in general practice: stochastic models. Psychological Medicine, Garralda, M. E. & Bailey, D. (986a). Psychological deviance in children attending general practice. Psychological Medicine 6, Garralda, M. E. & Bailey, D. (986). Children with psychiatric disorders in primary care. Journal of Child Psychology and Psychiatry 7, Garralda, M. E. & Bailey, D. (987). Psychosomatic aspects of children's consultations in primary care. European rchives of Psychiatry and Neurological Sciences 36, 39-3.

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