© Springer India 2015
Savita Malhotra and Subho Chakrabarti (eds.)Developments in Psychiatry in India10.1007/978-81-322-1674-2_1414. Nosology and Diagnostic Issues in Child and Adolescent Psychiatry
(1)
University of New South Wales, Sydney, NSW, 2052, Australia
Keywords
NosologyDiagnosisChild adolescentPsychiatry‘Diagnosis is not the end but the beginning of practice’.
Martin Fischer—German–American physician and writer
P. Dullur, Staff Specialist
1 Introduction
Diagnosis, classification and nosology are often lumped together as the same entity and the three terms are sometimes used interchangeably. It is important to clarify the difference between these entities. Nosology is the study of classification of disorders. Classification or grouping is an innate part of human development. For example, babies are able to mentally bisect space into left versus right categories (Quinn 2012) and can categorise people (mother vs. others) by the age of 4 months. Classification, therefore, is not necessarily only about classifying disorders. For example, there is a World Health Organisation (WHO) classification of psychosocial circumstances (WHO 1998).
The main systems of classification in psychiatry are the WHO sponsored International Classification of Diseases (ICD) (WHO 1992) and the American Psychiatric Association’s (APA) Diagnostic and Statistical Manual of Mental Disorders (DSM) (APA 1994). The DSM was created in 1952 with the specific aim of having a standardised classification system to diagnose psychiatric disorders. Revisions of the DSM have paralleled advances in the field of psychiatry, such as theoretical models, epidemiology, genetics, symptoms groups and treatment. The ICD is a WHO-generated classification of all groups of diseases. Mental illnesses were included as disorders in the 8th edition of the ICD in 1968. Over time, these two systems have in parallel, emerged as the main classification systems in psychiatry. Efforts are on for the last few decades to bring these two systems as close to one another as possible, and a “harmonisation committee” is currently attempting this. Other classificatory systems are specific to younger children, e.g. the classification 0–3 (DC: 0–3) in 1994, its revised second version (DC: 0–3R) in 2005, and the Research Diagnostic Criteria-Preschool Age (RDC-PA) in 2002.
The Webster’s dictionary defines diagnosis as “the art or act of identifying a disease from its signs and symptoms”. This is true for all of medicine. The difficulty, with psychiatry in general and child and adolescent psychiatry in particular, is in defining what these signs and symptoms are, and what they actually mean. Some related terms are syndrome, disorder and disease. All of these are wrongly used interchangeably at times. A syndrome is a set of signs and symptoms, which occur together more frequently than chance alone would dictate. An example is Down’s syndrome, in which various clinical signs and symptoms such as low intelligence, characteristic mongoloid face and a simian crease occur together. A syndrome does not necessarily imply either the cause or functional impairment. In Down’s syndrome of course, the aetiology is known (for example, trisomy chromosome 21). In other instances (e.g. Asperger’s syndrome), the aetiology is less clear. A disease is traditionally defined as a condition with a known aetiology. For example, diabetes is considered to be a disease, since it has multiple sign and symptoms (high blood sugar, polyuria and polydipsia) with a known aetiology (low insulin due to various factors, e.g. loss of the islets of pancreas). Most psychiatric entities are not “diseases” in the traditional sense of the term, since their exact aetiology is not currently known. Therefore, the term “disorder” is favoured. As per the ICD 10 (WHO 1992), a “disorder” implies the existence of a clinically recognisable set of symptoms or behaviour, associated in most cases with distress and with interference with personal functions. Therefore, the two pillars of making a diagnosis are as follows: firstly, the presence of a syndrome, meaning clear and specific signs and symptoms, and secondly, the presence of dysfunction.
2 Diagnosis Versus Formulation
So why is diagnosis important?
This is depicted in the following case vignette:
Ravi, a 13 year old boy, came to the clinic with his parents who complained that he was persistently disobedient and aggressive. The aggression was noted both at home and school and was often planned. He persistently carried a grudge. He often ran away from home and had been warned twice by the police. He smoked cigarettes and occasionally marijuana. The parents reported that he never accepted responsibility for what he did.
Non-diagnostic labels in such a person could include “a troubled child”, a “behaviourally disturbed child” or “too strict parents”. The treatment could be very variable. It could include working on the “external circumstances”, which led to his outbursts (e.g. counselling his parents or changing his school) to individual sessions with him (e.g. to find out what makes him angry and help him to find new coping strategies). It could also result in incorrect assumptions about the prognosis and outcome (e.g. “he will just grow out of it”). A diagnostic assessment, on the other hand, if done in a careful manner might reveal a diagnosis,in this instance one of conduct disorder. It should be pointed out that the basis for applying the diagnostic label is only the child’s behaviour, which must fit a certain pattern (e.g. aggression across multiple settings, deceitfulness and lacking respect for rules). These patterns make up the bulk of the classificatory manuals such as the ICD 10 and the DSM-IV. In modern schemes, the defining criteria for nearly all psychiatric diagnoses are purely descriptive and phenomenological (Dilling 2000). Identifying the criteria, therefore, acts as a clinical assessment tool, so that the presence of aggression and disobedience trigger certain lines of enquiry. For example, the DSM criteria for conduct disorder include aggression to people or animals, destruction of property, deceitfulness or theft and serious violation of rules. Knowing the DSM or ICD criteria would not only lead the clinician to objectively diagnose conduct disorder, but also help the clinician to rule out other diagnoses, such as Attention deficit hyperactivity disorder (ADHD) and specific reading disorders (dyslexia), which are comorbid in about one-third of patients with conduct disorder (Rutter et al. 1998).
If a diagnosis of conduct disorder is made, a considerable knowledge base is accessible in research. Thus, we know that Ravi’s long-term outlook without treatment is relatively poor; 40 % of children with conduct disorder go on to be convicted of three offences by the age of 17 (Farrington 1995). So suggesting that “he will grow out of it” would be misleading. The prognosis would be worse if the onset of his conduct disorder was before 4 years of age, if antisocial behaviour was frequent and widespread, if his IQ or reading age was low, if hyperactivity was present and if his parents were hostile towards him (Robins 1978). Having a diagnosis would also impact on the type of treatment chosen. For example, for conduct disorder, treatment options include cognitive problem solving therapy, parent management, functional family therapy and multi-systems therapy (Kazdin 1997).
However, no causal mechanisms are necessarily implied while making a diagnosis. This is significantly different from older theories, which attributed disorders to causes that could not be tested. (For example, suggesting that the boy in the above vignette has “castration anxiety”) Those who believe that the phenomenological approach taken in psychiatric classification is inferior or less scientific than that prevalent in physical medicine are mistaken—after all, epilepsy, hypertension and asthma are all diagnosed on the basis of observable phenomena with no assumptions of causality required. That is because the aetiology for the vast majority of psychiatric disorders is simply not known.
Thus systems of classification such as the DSM or the ICD serve multiple functions. Firstly, they define disorders, that is, serve to make diagnoses. Secondly, they serve as systems of classification. For example, the ICD 10 has classified psychiatric disorders into 10 different categories with multiple diagnoses within each category. Thirdly, they serve as means of communication between clinicians, researchers and other stakeholders such as consumers, policy makers, politicians and insurance companies. Finally, they drive research.
In general, child and adolescent psychiatric disorders are classified as internalising disorders, externalising disorders and developmental disorders. This is in addition to all the other traditional “adult” diagnoses such as psychotic or mood disorders. Internalising disorders, as the name suggests, are predominantly problems related to anxiety, fear, shyness, low self-esteem and emotional disturbances. Traditionally, these are less likely to be disruptive as parents or teachers may not necessarily notice them or consider them worthy of intervention. Internalising disorders include separation anxiety disorder, phobias of childhood and sibling rivalry disorder. Externalising problems, on the other hand, predominantly include behaviours such as hyperactivity, aggression and impulsivity. Diagnoses include ADHD, oppositional defiant disorder (ODD) and conduct disorder. Development colours all aspects of psychiatric disorders in children and adolescents. Independently though, developmental disorders are classified into problems of global impairment (mental retardation) or specific disorders (e.g. speech delay). The separation between these disorders is by no means absolute. Depressive symptoms can occur in conduct disorders, anxiety symptoms can occur in ADHD, and intellectual impairment can occur with any disorder.
3 Multi-axial Framework
Both the ICD 10 and DSM-IV have a multi-axial framework for psychiatric disorders in childhood and adolescence (WHO 1996). The ICD 10 axes are described below.
Axis I:
Clinical psychiatric syndromes: Here, criteria for particular diagnoses are applied, as described in the relevant manuals for ICD 10.
Axis II:
Specific disorders of development: These include disorders of speech and language, reading, spelling and motor development.
DSM-IV codes Axis I and Axis II of the ICD 10 on Axis I.
Axis III:
Intellectual level: Mental retardation is primarily coded on this Axis. In DSM-IV, mental retardation is included in Axis II.
The multi-axial system for diagnosing mental illness does not necessarily convey details about mental retardation itself. Therefore, Dr Satish Girimaji (2008) proposes the following multi-axial system specifically for mental retardation:
Axis I:
Presence and degree of mental retardation (e.g. mild mental retardation)
Axis II:
Aetiologic or syndromal diagnosis (e.g. fragile X syndrome)
Axis III:
Associated medical problems (e.g. epilepsy)
Axis IV:
Associated psychiatric problems (e.g. ADHD)
Axis V:
Family and psycho-social axis (e.g. poor awareness, high stress levels and over-expectation).
It is notable that words and terminology have a way of evolving over time, especially in the context of stigma. The words “idiot”, “imbecile” and “moron” were scientific ways of describing degree of mental retardation in the early part of the twentieth century before giving way to “mental retardation”. The term “intellectual disability” is preferred in both the DSM-5 and ICD 11 classifications (Luis Salvador-Carull 2011).
Axis IV:
Associated medical conditions: All medical conditions are coded on Axis IV. A few have specific associations with psychiatric disorders, for example, tuberosclerosis predisposes to autism and Cornelia de Lange syndrome to self injury. Even when there is no specific disorder, congenital syndromes are often characterised by a particular pattern of behaviour (Flint and Yule 1994). In DSM-IV, medical conditions are included under Axis III.
Axis V:
Associated abnormal psychosocial conditions: These include a range of psychosocial hazards, from abnormal intra-familial relationships, e.g. physical or sexual abuse, family history of mental disorders, distorted intra-familial communication patterns, abnormal upbringing (e.g. in an institution), acute life events and chronic interpersonal stress arising from difficulties at school. As the number of psychosocial adversities goes up, the rate of psychiatric disorders increases (Garmezy and Masten 1994). Rutter (1987) found that no single psychosocial adversity was associated with any particular disorder; rather, the total number of adverse situations was important. Those with only one adverse situation had no increase in disorders over those without adversity, whereas those with two adverse situations had a 4-fold increase in disorders. Conduct disorder is particularly associated with a poor immediate psychosocial environment (Steinhausen and Erdin 1992), whereas emotional disorders are associated more with acute life events and school-related chronic stressors (Moselhy et al. 1997). Psychosocial issues are coded on Axis IV in the DSM-IV.
Axis VI:
Global social functioning: Here, a judgement is made on a dimensional scale, ranging from superior social functioning to profound and pervasive social disability. Studies based on DSM-IV criteria often use the Children’s Global Assessment Scale (CGAS) (Shaffer et al. 1983). DSM-IV includes global functioning on Axis V.
Of importance is that the DSM-5 (APA 2013) has done away with the multi-axial system, specifying that all diagnoses are equally important, and therefore, a multi-axial framework is no longer necessary.
4 Diagnostic Formulations
An important and distinct, yet related concept is that of the diagnostic formulation. The formulation is a statement, which puts the patient in perspective. While a diagnosis is not tailored for an individual patient, a formulation is designed to do precisely that. It answers the question: “Why is this patient here, now?”
This is depicted in the following case vignette:
Sita is a 6 year old girl who presented to the clinic with school refusal. Sita lives in Bangalore, with her parents, both software engineers. She was cared for at her grandparent’s house by her grandparents while both parents went to work. The fear of school started when her parents had talked about school in a casual way, discussing the punishments they had been given when they had started school, years ago. This fear was heightened, when on a visit to the school prior to start of the session, a teacher had said jokingly, that ‘“bad children” were often punished by being locked up in the bathroom with cockroaches. On the first day of school, Sita and her mother went together, but Sita cried so loudly that the school advised her mother to take her back home. This pattern was repeated over the next few days. As a result, she would constantly cling to her mother in the mornings and would cry for long time after her mother left for work. Her grandparents reported that the crying did not settle after her mother left, but would continue for hours together later. Her mother spent increasingly longer times at home trying to settle Sita down, but Sita’s clinginess worsened. As a result, the mother found that she could no longer reach work on time. As time passed, Sita started complaining of significant abdominal pain in the morning. This resulted in several trips to specialists to identify the cause of the pain and treat it, to no avail. The pain would often disappear when the family decided they would stop trying to send her to school for that day. All attempts to get her to school resulted in severe screaming and “tantrums”. After giving up trying to get her to school, the parents would go to work, leaving Sita at home with the grandparents. She would pass her time by watching TV and playing computer games. However, at home, her clinginess to her mother worsened and she started complaining of repeated dreams of a monster taking away her mother, and could no longer sleep in her own bed. This fear of something happening to mother extended to all situations and the mother found that she could neither work, nor socialise. Her relationship with her husband worsened as her husband would blame her for not managing Sita’s anxiety. One professional they visited labelled her as an “anxious child” and said “anxiety is common around getting to school” and advised the parents to “give her time”. Another suggested that the parents were being “too soft” on her, and that “tough love” was needed.
In this case, careful assessment and application of proper criteria revealed that she fulfilled several criteria of separation anxiety disorder including: developmentally inappropriate and excessive anxiety concerning separation from a key figure (in this case the mother), excessive distress, school refusal, nightmares around separation, difficulty sleeping and repeated complaints of physical symptoms. Significant dysfunction included loss of education for Sita, loss of work for her mother and marital discord between the parents.
On further assessment, Sita was anxious by temperament. Both her parents had social phobia. The parents described themselves as anxious by nature as well. A related feature was that they tended to have constantly anxious interactions with Sita (e.g. “Don’t go to there, an insect might bite you”).
Therefore, the diagnosis would be as follows:
Axis I: Separation anxiety disorder
Axis II: Nil
Axis III: Nil
Axis IV: Nil
Axis V: Family history of anxiety, anxious interactions between parents and child, marital discord, loss of education and work opportunities
Axis VI: CGAS score of 60.
Making the diagnosis does not necessarily lead to proper management. A formulation, specific to the case is needed. Formulations are of several types: these include a diagnostic formulation, which incorporates key diagnostic criteria, a psychodynamic formulation, which explains symptoms in a psychodynamic way (Perry et al. 1987) or a clinical formulation which incorporates a biopsychosocial model (RANZCP guidelines 2012). A clinical formulation incorporates vulnerability and precipitating factors and links these to maintaining factors.
Therefore, a useful formulation in Sita’s case would be:
“Sita is a 6 year old girl who presented with severe separation anxiety with school refusal. This has significantly impacted the functioning of the family. Sita is vulnerable to anxiety disorders due to the following factors: biologically: a family history of anxiety, anxious temperament; and, psychologically, due to anxious interactions resulting in a negative appraisal of normal stimuli. The disorder was precipitated by social factors (being scared by teacher) and seems to be maintained by avoidance behaviours at home (computer games).
Based on the formulation, the following management was done.
Sita and her family were seen by a child psychiatrist. After the above diagnosis and formulation were made, the psychiatrist spent a long time in educating the parents regarding the illness. Medical illness such as hypothyroidism and anaemia were ruled out. Interventions included forming a good therapeutic relationship with Sita, relaxation exercises and a program of graded exposure coupled with relaxation exercises, which involved both the school situation and separation anxiety. The psychiatrist worked with both parents and through them, with the school. Medication was deferred in view of the age of the child. The parents agreed to seek treatment for their own anxiety disorders. Four months later, Sita was well integrated at school, but continued to be anxious. The mother was able to return to work.
Thus, diagnosis and formulation are the twin pillars on which management should be based.
Several important issues dog the ICD and DSM systems of classification. These include, the use of categorical versus dimensional approaches (Coghill and Sonuga-Barke 2012); the use of multiple axes or a single axis (Taylor and Rutter 2008); the excessive number of diagnostic categories (Rutter 2011), the large number of “Not otherwise specified NOS” diagnoses (Rutter 2011); whether to diagnose comorbid disorders separately (as in the DSM), or to have combined diagnoses (e.g. hyperkinetic conduct disorder or depressive conduct disorder in the ICD 10) (Rutter and Uher 2012); whether functional impairment will need to be made a necessary criterion for making a diagnosis (Rutter 2011); how to integrate the ICD and DSM systems; the issue of homogeneity versus heterogeneity of diagnoses (Scott 2001) and so on. These will not be discussed further in this chapter.
5 Influence of Child and Adolescent Issues on Specific Diagnoses and Their Classification
Given that children are constantly growing, a good knowledge of normal development is necessary to correctly differentiate the normal from the pathological. For example, temper tantrums are normal at the age of two, not at the age of eight years. Imaginary friends are usual for five-year-olds, but not 15-year-olds. A depressed 5-year old child will not be able to articulate suicidal thinking patterns, while a 16-year old would. The ability to identify time patterns is poor in a 5-year old child, average in an 11-year old one and adult like by the age of 15 years. This means that an 8-year old would not be able to describe events in a chronological sequence, whereas a 15-year old adolescent would. Therefore, flexibility is required while attempting to fit particular behaviours into a diagnostic category. An important issue in making a diagnosis is an understanding of the context in which the problem occurs. These contextual factors could be family, school or sociocultural issues. For example, poor attention at school in a child due to an inappropriate school placement would not merit a diagnosis of attention deficit disorder. Under-stimulation in a child who may have a slow to warm-up temperament may result in quasi-autistic symptoms, which resolve readily when the child is placed in a different environment. Cultural differences may also affect diagnostic concepts and practice. Economic disadvantage, for example, is associated with conduct and attentional problems, but the meanings of such relationships often remain unclear.
Once developmental difficulties are identified, it is helpful to decide if abnormalities are due to delay or to deviance from the usual pattern of development. For example, a child may exhibit a speech problem. If she produces only a handful of words, but in the appropriate context, she may suffer from expressive speech delay. A diagnosis, however, can be made only if the delay is exclusive to speech and not part of a global delay. If global delay exists, a diagnosis of mental retardation (intellectual disability) would be more appropriate. If the delay in the speech is greater than the mental age of an intellectually delayed child, both mental retardation and a speech delay should be diagnosed. On the other hand, if the speech is atypical, e.g. lacking reciprocity or tone and accompanying gestures, a diagnosis of autism might be considered.
6 Psychiatric Disorders Among Children and Adolescents
This section deals with some of the disorders specific to children and adolescents and explores the differences between the two prevalent systems of classification, the DSM and the ICD.
Anxiety disorders: The ICD 10 defines emotional disorders in children as “mainly exaggerations of normal developmental trends rather than phenomena that are qualitatively abnormal in themselves”. It also affirms that developmental appropriateness is the key diagnostic feature, which differentiates these disorders from other neurotic disorders. For example, agoraphobia is not part of childhood anxieties and so is abnormal irrespective of the age of the child. On the other hand, separation anxiety is normal at the age of 18 months, but not at age six years. The ICD and DSM systems differ significantly with relation to anxiety disorders in childhood. The ICD 10 includes separation anxiety disorder, phobic anxiety disorder of childhood (abnormal degree of normal childhood fears), social anxiety disorder of childhood (extreme wariness of strangers or new situations) and sibling rivalry disorder (severe emotional disturbance usually following birth of a younger sibling). The DSM, on the other hand, recognises only separation anxiety disorder as a discrete diagnosis among the above. As a result, studies (e.g. Adornetto et al. 2012) have found poor concordance between ICD 10 and DSM-IV diagnoses of childhood anxiety disorders. A PubMed search with the keywords “sibling rivalry disorder” returned no results, while a search with keywords “sibling”, “rivalry” and “disorder” revealed a single relevant article (Snowling 2011), which talks of the sibling relationship, but not of “sibling rivalry disorder”. In the absence of any research, this disorder could perhaps be eliminated from the ICD 11. This is one of the issues raised by Sir Michael Rutter (2011), who has suggested that the number of diagnostic categories in the ICD 10 is excessive and some are rarely used; therefore, there is a need to eliminate some of the diagnoses in the DSM-5 as well.
Conduct disorder: The ICD 10 and the DSM-IV are quite discordant in the classification of conduct disorders. The ICD 10 category of conduct disorder includes: conduct disorder in the family context, unsocialised conduct disorder, socialised conduct disorder and ODD. The DSM-IV, on the other hand, describes conduct disorder as standalone diagnosis, with onset in childhood or adolescence, and identifies ODD as a separate condition. Clinical experience in India suggests that the “conduct disorder within the family context” is a commonly seen condition. However, researchers suggest that sub-classification of conduct disorder in the ICD-10 has not proved satisfactory and recommend that it be discontinued in the ICD 11 (Ruter 2011). Another issue is that in both DSM-IV and ICD-10, sub-classification differs between childhood and adulthood. For example, conduct disorder in childhood is sub-classified as described above, whereas antisocial personality disorder (ASPD) is not. Psychopathic features are necessary in diagnosing antisocial personality, but not necessary for diagnosing conduct disorder in childhood. Furthermore, conduct disorder is treated as an Axis I clinical disorder in both classificatory systems, whereas ASPD is treated as an Axis II disorder. Given the extensive evidence for continuity over time between the two, that makes little sense. This is particularly so because the diagnosis of ASPD in DSM-IV requires evidence of conduct disorder in childhood. Therefore, a lifespan approach, which brings conduct disorders and ASPD together, is much needed (Moffitt et al. 2008). Yet, it must be noted that in over half the patients with an onset in childhood, the disorder does not persist into adult life (Odgers et al. 2007a).
One of the principles of the ICD 10 is that it encourages clinicians to make a combined diagnosis wherever possible. Therefore, it includes two such categories: depressive conduct disorder (which highlights the fact that a high proportion of children with conduct disorder have depressive features) and hyperactive conduct disorder (comorbid ADHD and conduct disorder). Odgers et al. (2007b) comment on the persistence of conduct disorder into adulthood and propose that ASPD is more likely if it is accompanied by over-activity. Therefore, they recommend that the criteria for conduct disorder should include both components. This is done to an extent in the ICD 10 in the shape of the hyperactive conduct disorder category. However, research is unclear whether this represents separate disorders or not.
Robins and Guze, in a seminal paper in 1970, defined the criteria to label a particular entity as a disorder. These included a clinical description, laboratory studies, delimitation from other disorders, follow-up studies and family studies. In psychiatric nosology, identifying laboratory studies is probably the least helpful to establish the validity of a diagnosis, owing to the lack of such studies. Hence, researchers have attempted to use other indicators. The difficulty in child and adolescent psychiatry is the high rate of comorbidity between disorders. As mentioned, the ICD 10 tends to integrate comorbid conditions into a separate diagnosis, while DSM aims to diagnose them as separate entities. Therefore, some studies have tried to identify these patterns and establish whether these are same or different disorders.
In a retrospective study from India (Malhotra et al. 1999), the clinical and phenomenological correlates of hyperkinetic conduct disorder and conduct disorder, as per the ICD-10 diagnostic criteria were examined. Twenty patients with hyperkinetic conduct disorder and 25 patients with conduct disorder were compared on socio-demographic variables, temperament and specified clinical variables. The two groups differed in terms of the hyperkinetic conduct disorder group having a younger age of onset, a more gradual development of and a longer duration of conduct symptoms as compared to the children with conduct disorder. Children with hyperkinetic conduct disorder had differences in temperament, e.g. distractibility, lower IQ, more perinatal complications and delayed milestones, as compared to the conduct disorder group. The authors proposed that the two disorders followed different pathways of development towards conduct symptomatology, lending some credibility to the separation of these two disorders.
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