Child psychopharmacology: Is it more similar than different from adult psychopharmacology?

Despite having a large chunk of human population, Asian countries face shortage of mental health professionals. There is further shortage of doctors dealing with special groups of population like the children, the elderly, and the medically ill. However, in this era of super-specializations, are the basic principles of general psychopharmacology being forgotten? Dealing with child population is different and often more difficult than adult population but are management guidelines for the two populations vastly divergent? A close look at this paints a different picture. Psychotherapies applied in adults and those in children and adolescents are disparate owing to cognitive, social, emotional, and physical immaturation in children and adolescents. But the drugs for the treatment of pediatric psychiatric disorders are mostly similar to those prescribed for adults (case in point -bipolar disorders, obsessive compulsive disorder, schizophrenia). Rather than focusing energy on propagating the differences in assorted subgroups of population, honing of skills regarding intricacies of psychopharmacology is required to be emphasized. Detailed history taking, careful evaluation of the patient, sound diagnostic formulation, and prescribing medications which are tailor made to the patient will all go a long way in ensuring a functional recovery of the patients irrespective of the group they belong to.

INTRODUCTION

Asia has some of the largest conglomerations of human populations and also the fastest growing economies of the world. The south Asian region alone houses one-fifth of the psychiatrically ill population of the world. Despite these widely known facts, there is a serious shortage of mental health professionals in this region. The ongoing “brain drain” to greener pastures (i.e., the western/developed world) is only adding insult to the injury.

The ratio of mental health personnel to population is nowhere near the WHO recommended levels in the less developed countries of the Asian continent. In China, there are about 15 000 psychiatrists for 1.2 billion people (about 1:80 000). In India, with 1 billion people, there are but 3000 psychiatrists (about 1:330 000), Indonesia has about 450 psychiatrists for 210 million people in over 13 000 islands.[1] Doctors dealing with children's psychiatric problems are still lesser in number. Formal training in child psychiatry is still in its nascent stage in India and in other countries of the region as well. There is a widely held belief that child psychiatry is vastly different from adult psychiatry. Propagating this fact might eschew many a capable psychiatrists from taking up cases belonging to this age group.

As is known in medical circles, dealing with children is quite different than dealing with adults; pertaining to history taking (from subjects as well as care givers), physical examination (anthropometry forms an important component of examination of a child, other findings can be depressed anterior fontanel in a case of acute gastroenteritis with dehydration, bulging fontanel as a mark of raised intra-cranial pressure, wrist widening as a sign of vitamin D deficiency, or any dysmorphic features like low set ears or mongoloid slant pertaining to a particular syndrome), and interpretation of laboratory findings.

Besides, certain diseases are known to affect children in much larger numbers than they do the adults (meningitis, pneumonia, and upper respiratory tract infections) and certain symptoms might be unique to this population (febrile convulsions, infantile tremor syndrome, cerebral palsy, rheumatic fever, breath holding spells, manifestation of congenital heart diseases) or its presentation might be different than that of the adults.

However, pivotal question to be asked at this point is, once a diagnosis has been arrived at, do pharmacological interventions differ so much?

The patient's age (geriatric/middle aged/pediatric), gender (male/female), weight, surface area, associated morbidities (medical/surgical/psychiatric/substance use, etc.), and probable side effects of drugs (and their effect on the patient population) are mostly taken into account while prescribing medications. We should and must aim at tailoring the medications prescribed to the needs and demands of the patient. Only then, can a proper compliance and better recovery be ensured.

Do we as clinicians not consider while prescribing medications to each person his/her liver functions, renal functions, medical conditions, or any other unique factors that might warrant attention? So, how much is child psychopharmacology really different from adult?.

Childhood psychiatric disorders can mainly be divided into the following two broad categories: those which are also seen in adult population (presentation may be similar or different) e.g., bipolar affective disorder, unipolar depression, schizophrenia, dissociative, and somatoform disorders, or those which are primarily seen in young population e.g., attention deficit hyperactive disorder (ADHD), autistic disorder, specific learning disorders, and other associated pervasive developmental disorders.

For the sake of comparison, we shall primarily consider those disorders which are common to both the populations (although even in cases of disorders such as adult ADHD the drugs prescribed remain almost the same, only the amount changes, which can be explained once the weight criteria is taken into consideration).

Apparent differences in child and adult psychopharmacology

The guidelines available in prescribing medications to children and adults are mostly similar in the drugs prescribed. The difference is usually in the dosage and some special considerations to be taken into account. Most of these considerations usually pertain to pharmacodynamic and pharmacokinetic factors (which are taken into considerations in other populations also). They also might differ on what drugs are approved for use in children, but primary reason for this discrepancy is caused by lack of adequate number of studies done in this population due to ethical considerations rather than the differing efficacy of the drugs. We shall first discuss the primary issues which supposedly differ between the two form of psychiatry namely adult and childhood.

Primary issues in child and adolescent psychiatry vis-à-vis adult

Difficult diagnosis (owing to varying presentations and frequent comorbidities)

Consideration regarding informed consent from parents and children as well (more so if child's age is above 7 years)

Continuing maturation changes in children and adolescents

Concerns about long-term use of drugs

Concerns about abuse potentiality of drugs

Inadequate studies regarding efficacy of drugs and possible exclusion of severely ill children primarily due to ethical concerns

Differing pharmacodynamics and pharmacokinetics as compared to adult population

Greater advocacy of concurrent psychotherapy.

A careful look at above mentioned concerns would again point to the fact that these are some of the concerns which should be borne in mind while treating all classes of patients and not children only. E.g., long-term use of drug is as much a concern in adult patients (cases of schizophrenia, bipolar affective disorder multiple episodes, recurrent depression, etc.). Similarly, no doubt one has to consider the ongoing maturation changes in children, but we also have to consider degenerative changes in elderly, effects of pregnancy and post-partum metabolic changes in women, etc.

As far as abuse potential of drugs in children is concerned, among psychiatric medications, only two classes of drugs are potential drugs of abuse: Stimulants (methylphenidate) and benzodiazepines (e.g., anti-anxiety drugs such as alprazolam). However, the majority of children with psychiatric disorders do not abuse these medications. For instance, although stimulants can be abused by those genetically predisposed to substance abuse; such drugs generally do not produce euphoria in ADHD children. In fact, many children with ADHD experience stimulants as causing mild dysphoric effects. Additionally, data now exist to strongly indicate that among those with ADHD, the use of stimulants actually decreases the risk of substance abuse (by about 50% when compared to drug abuse rates which are high among non-treated ADHD subjects).[23]

Regarding greater advocacy of concurrent psychotherapy in children, studies carried out on adult population too have emphasized the role of psychotherapy with psychopharmacology. For most of the psychiatric disorders, a combination of both has been proven to be more effective than either alone.

Similarities between psychopharmacological principles in children and adults can be further highlighted by taking example of treatment of bipolar affective disorder.

Bipolar disorder: Treatment approaches in children and adults

Pavuluri et al., 2004,[4] devised an algorithm for treating bipolar pediatric patients and concluded that manic and mixed symptoms require mood stabilizer monotherapy or combination therapy with an SGA or second mood stabilizer. Depression may require lithium, but there are no controlled trials to address depressive symptoms in this population. The roles of mood stabilizer monotherapy,[567] second generation antipsychotic (SGA) monotherapy,[89] mood stabilizer plus antipsychotic,[10111213] and combined mood stabilizer[1415] have all been highlighted in the acute treatment of mania in pediatric population.

Studies done regarding maintenance treatment for bipolar disorder in children and adolescents have also concluded favorable efficacy of both lithium and divalproex,[16] although some studies have raised doubts over the efficacy of lithium in juvenile patients for long-term prophylaxis.[17] Long-term maintenance therapy has been advocated by Srinath et al., 1998,[18] for young hospitalized bipolar patients.

Study guidelines (e.g., published by Indian Psychiatric Society, 2007) and books like Principle and Practice of Psychopharmacology, 4th Edition[19] (Eds. Janicak et al., 2006) also mention the efficacy of above mentioned dugs.

A close look at these would reveal that there is not much difference in treatment between the adults and pediatric age group. Of course, one has to be watchful regarding side effects and expect that drugs would take a longer time to subside an acute episode and dose required may be higher than expected (because of higher rates of metabolism in children) along with the fact that more than one mood stabilizer might be required. But these all facts one would consider even while treating adult patients. Where one mood stabilizer is not showing good response, the use of second mood stabilizer is warranted. Similarly, dose adjustments are frequently required keeping in view the emerging side effects and response.

Schizophrenia: Treatment approaches in children and adults

The guidelines for treatment of schizophrenia too are similar in adults. SGAs are to be given preference over the typical ones. Careful monitoring of weight and metabolic parameters is required. There are a few short-term studies regarding the use of SGAs in youth. Hence, the potential for long-term side effects in this population is currently not known. This also has implications on the use of antipsychotics to prevent recurrence and relapse. Even though not systematically studied, children with schizophrenia almost certainly need this approach as well.

It is also recommended that in young population, a trial of off-medication be considered to re-evaluate the possible cause of such episodes and the need for continuing antipsychotic medication.

OCD: Treatment approaches in children and adults

The guidelines also advice almost similar line of management where treatment of Obsessive Compulsive Disorder (OCD) is concerned, whether treating children or adults, i.e., a combined approach of medication (SSRIs are well tolerated) and some form of behavioral intervention (CBT, Exposure Response Prevention).

CONCLUSIONS

Honing of skills regarding intricacies of psychopharmacology is the need of the hour. Detailed history taking, careful evaluation of the patient, sound diagnostic formulation, prescribing medications which are tailor made to the patient (i.e., take into account the comorbidities, economic status, co-existing medical conditions, compliance issues, side effect profile, and previous treatment response), timely follow-up, and adjusting medications according to treatment response and appearing side effects will all go a long way in ensuring a functional recovery of the patients irrespective of the group they belong to.