The overlap of DSM-IV syndromes: potential implications for the practice of polypsychopharmacology, psychiatric drug development, and the human genome project

The Essential Parallels Between Clinical Practice and the Scientific Method

This column presents a way of conceptualizing the clinical practice of medicine including psychiatry within the framework of the scientific method. The goal is to aid practicing clinicians as well as trainees. This conceptual framework will improve the care of patients as it applies a discipline relative to giving time-limited trials of the various treatments available and then an assessment of whether the treatment worked adequately or not and what to do in the latter case. In this way, this approach should decrease the risk of excessive multiple medication use to treat a specific patient. Incorporating this conceptual framework early in the training of mental health care prescribers would be desirable.

Drug Development in Psychiatry: The Long and Winding Road from Chance Discovery to Rational Development

Based extensively on tables and figures, this chapter reviews drug development in psychiatry with an emphasis on antidepressants from the 1950s to the present and then looks forward to the future. It begins with the chance discovery drugs and then moves to through their rational refinement using structure activity relationships to narrow the pharmacological actions of the drugs to those mediating their antidepressant effects and eliminating the effects on targets that mediate adverse effects. This approach yielded newer antidepressants which compared to older antidepressants are safer and better tolerated but nevertheless do still not treat the approximately 40% of patients with major depression (MD) which is unresponsive to biogenic amine mechanisms of action. This form of MD is commonly referred to as treatment resistant depression. Esketamine is an antidepressant which has a novel mechanism of action: blockade of the glutamate NMDA receptor. These studies coupled with earlier studies with other NMDA drugs suggest approximately 60% of patient with TRD are rapidly and robustly responsive to this mechanism of action. Thus, there appears to be three forms of MD based on pharmacological responsiveness: (a) 60% responsive to biogenic amine mechanisms of action, (b) 24% (i.e., 40 × 60%) responsive to NMDA but not to biogenic amine mechanisms of action, and (c) 16% (i.e., 40-24%) not responsive to either of these mechanisms of action. Scientific investigation of these three groups may yield important information about the pathophysiology and/or pathoetiology of these different forms of MD. This information coupled with studies into the neurobiology (e.g., imaging studies, connectomes to name a few approaches being used) and genetics of MD should provide the fundamental knowledge which will permit a rational search for and discovery of newer antidepressant drugs and other somatic and psychotherapeutic approaches to the treatment of patients with different forms of MD based on pathophysiology and pathoetiology. Examples are given of how such discovery and development have occurred in other areas of medicine and even in central nervous system (CNS) space including six novel mechanisms of action CNS drugs which have been successfully developed and marketed over the last 25 years.

Could immersive daydreaming underlie a deficit in attention? The prevalence and characteristics of maladaptive daydreaming in individuals with attention-deficit/hyperactivity disorder

OBJECTIVE

Maladaptive daydreaming (MD) entails excessive immersion and engagement in complex fantasy worlds, causing distress and impairing functioning. Maladaptive Daydreamers often report that existing diagnostic labels are unhelpful for them. Previous studies reported high rates of comorbid attention deficit hyperactivity disorder (ADHD) among persons with MD, raising the question of their separateness. This study explored whether MD differs essentially from ADHD by examining an ADHD sample, hypothesizing a much lower incidence of MD.

METHOD

Adults diagnosed with ADHD (N = 83) were assessed for ADHD symptoms, MD, depression, loneliness, and self-esteem. Participants who exceeded the study's cutoff score for suspected MD were invited to participate in a structured diagnostic interview for MD.

RESULTS

In accordance with the hypothesis, only 20.5% of the ADHD sample met the proposed diagnostic criteria for MD. Compared with ADHD-only participants, this subgroup presented increased depression, loneliness, and lowered self-esteem.

CONCLUSION

MD has unique clinical characteristics that are distinct from ADHD. We suggest that in some cases presenting with ADHD symptoms, an MD conceptualization may better explain the clinical picture. Future research should aim at a better differentiation of daydreaming, ADHD, and related constructs such as mind-wandering.

Subtypes of Major Depressive Disorder Based on Pharmacological Responsiveness

Major depressive disorder (MDD) is a descriptive, syndromic diagnosis which will likely be discovered to be more than a single disorder when understood from a pathobiological or pathoetiological perspective. To date, attempts to divide this disorder into more homogenous phenotypes on the basis of signs and symptoms have not yielded more information on the pathobiological or pathoetiological factors that can cause a major depressive episode. This column proposes a new way of dividing MDD into 3 subtypes based on responsiveness to pharmacological treatments that are pharmacologically quite different from each other: type 1, which is responsive to treatment with biogenic amine antidepressants; type 2, which is not responsive to treatment with biogenic amine antidepressants but is responsive to antidepressants that work on the glutamine neurotransmitter system via the N-methyl-D-aspartate receptor; and type 3, which is not responsive to either of these 2 types of antidepressants. The goal of this formulation is to develop biologically meaningful subtypes that can be further studied to understand the pathobiology underlying these 3 types of MDD with the goal of developing newer treatments and earlier ways of diagnosing these conditions.

Drug Development in Psychiatry: The Long and Winding Road from Chance Discovery to Rational Development

Based extensively on tables and figures, this chapter reviews drug development in psychiatry with an emphasis on antidepressants from 1950s to the present and then looks forward to the future. It begins with the chance discovery drugs and then moves to through their rational refinement using structure activity relationships to narrow the pharmacological actions of the drugs to those mediating their antidepressant effects and eliminating the effects on targets that mediate adverse effects. This approach yielded newer antidepressants which compared to older antidepressants are safer and better tolerated but nevertheless do still not treat the approximately 40% of patients with major depression (MD) which is unresponsive to biogenic amine mechanisms of action. This form of MD is commonly referred to as treatment resistant depression. Esketamine is an investigational antidepressant which has a novel mechanism of action: blockade of the glutamate NMDA receptor. Positive trials reported this year for esketamine make it likely this drug will be approved next year in the USA. These studies coupled with earlier studies with other NMDA drugs suggest approximately 60% of patient with TRD are rapidly and robustly responsive to this mechanism of action. Thus, there appears to be three forms of MD based on pharmacological responsiveness: (a) 60% responsive to biogenic amine mechanisms of action, (b) 24% (i.e., 40 × 60%) responsive to NMDA but not to biogenic amine mechanisms of action, and (c) 16% (i.e., 40 - 24%) not responsive to either of these mechanisms of action. Scientific investigation of these three groups may yield important information about the pathophysiology and/or pathoetiology of these different forms of MD. This information coupled with studies into the neurobiology (e.g., imaging studies, connectomes to name a few approaches being used) and genetics of MD should provide the fundamental knowledge which will permit a rational search for and discovery of newer antidepressant drugs and other somatic and psychotherapeutic approaches to the treatment of patients with different forms of MD based on pathophysiology and pathoetiology. Examples are given of how such discovery and development has occurred in other areas of medicine and even in central nervous system (CNS) space including six novel mechanisms of action CNS drugs which have been successfully developed and marketed over the last 25 years.

Drug-drug Interactions in Psychiatric Practice, Part 4: Classification of Neuropsychiatric Medications Based on Their Principal Mechanisms of Action (With Updated Neuroscience-based Nomenclature)

This column is the fourth in a series exploring drug-drug interactions (DDIs) with a special emphasis on psychiatric medications. This column discusses how drugs with multiple mechanisms of action have the potential to interact pharmacodynamically by the mechanism(s) mediating their therapeutic indication and for some drugs by other mechanisms (ie, drugs with multiple mechanisms of action). In this and the next column in this series, we present a classificatory system in the form of 2 tables that prescribers can use to predict the action of a neuropsychiatric drug when used alone as well as DDIs that can occur when it is used in combination with other drugs. The table in this column presents neuropsychiatric medications classified according to their mechanism(s) of action. The next column in this series will present a parallel table summarizing major types of pharmacodynamic DDIs based on mechanism of action and discuss strategies for minimizing adverse outcomes from such unintended DDIs. The authors recommend that health care providers' knowledge of the drugs they frequently prescribe include both their generic and brand names (to avoid confusion leading to dispensing the wrong drugs), routinely used doses, pharmacokinetics including half-lives, pharmacodynamics including mechanism(s) of action and binding profile for specific receptor(s) (not specifically discussed here but available in other columns by the first author), adverse effect profiles, potential DDIs, and the evolving research literature on these agents.

CNS Drug Development: Lessons Learned Part 3: Psychiatric and Central Nervous System Drugs Developed Over the Last Decade-Implications for the Field

This column reviews the divergence between the approach to drug development in infectious disease, oncology, and immunology versus psychiatry. Between 2009 and 2016, 254 new drugs were approved. Of those, only 9 were for a psychiatric indication; another 5 were labeled to treat central nervous system disorders that are not considered psychiatric per se but are frequently found in individuals with psychiatric illnesses (eg, substantial weight gain). There were 2 additional new products for psychiatric indications that involved either a combination product (Contrave) or a prodrug for the production of aripiprazole (Aristada). The column discusses the reasons behind these different rates of development of psychiatric and/or central nervous system drugs compared with drugs in the areas of infectious disease, oncology, and immunology, and it predicts that this situation will change over the next century as we develop an improved understanding of the neurobiology underlying specific psychiatric illnesses.

Development of self-inflicted injury: Comorbidities and continuities with borderline and antisocial personality traits

Self-inflicted injury (SII) is a continuum of intentionally self-destructive behaviors, including nonsuicidal self-injuries, suicide attempts, and death by suicide. These behaviors are among the most pressing yet perplexing clinical problems, affecting males and females of every race, ethnicity, culture, socioeconomic status, and nearly every age. The complexity of these behaviors has spurred an immense literature documenting risk and vulnerability factors ranging from individual to societal levels of analysis. However, there have been relatively few attempts to articulate a life span developmental model that integrates ontogenenic processes across these diverse systems. The objective of this review is to outline such a model with a focus on how observed patterns of comorbidity and continuity can inform developmental theories, early prevention efforts, and intervention across traditional diagnostic boundaries. Specifically, when SII is viewed through the developmental psychopathology lens, it becomes apparent that early temperamental risk factors are associated with risk for SII and a range of highly comorbid conditions, such as borderline and antisocial personality disorders. Prevention efforts focused on early-emerging biological and temperamental contributors to psychopathology have great potential to reduce risk for many presumably distinct clinical problems. Such work requires identification of early biological vulnerabilities, behaviorally conditioned social mechanisms, as well as societal inequities that contribute to self-injury and underlie intergenerational transmission of risk.

Neural substrates of trait impulsivity, anhedonia, and irritability: Mechanisms of heterotypic comorbidity between externalizing disorders and unipolar depression

Trait impulsivity, which is often defined as a strong preference for immediate over delayed rewards and results in behaviors that are socially inappropriate, maladaptive, and short-sighted, is a predisposing vulnerability to all externalizing spectrum disorders. In contrast, anhedonia is characterized by chronically low motivation and reduced capacity to experience pleasure, and is common to depressive disorders. Although externalizing and depressive disorders have virtually nonoverlapping diagnostic criteria in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, heterotypic comorbidity between them is common. Here, we review common neural substrates of trait impulsivity, anhedonia, and irritability, which include both low tonic mesolimbic dopamine activity and low phasic mesolimbic dopamine responding to incentives during reward anticipation and associative learning. We also consider how other neural networks, including bottom-up emotion generation systems and top-down emotion regulation systems, interact with mesolimbic dysfunction to result in alternative manifestations of psychiatric illness. Finally, we present a model that emphasizes a translational, transdiagnostic approach to understanding externalizing/depression comorbidity. This model should refine ways in which internalizing and externalizing disorders are studied, classified, and treated.

Post-dexamethasone cortisol, self-inflicted injury, and suicidal ideation among depressed adolescent girls

Although the dexamethasone suppression test (DST) has limited use as a biomarker of depression given inadequate sensitivity and specificity, it marks prospective risk for suicide among adults. However, few studies have examined associations between the DST, suicidal ideation, and self-inflicted injury (SII) among adolescents, even though SII is the single best predictor of eventual suicide. We evaluated the DST as a correlate of suicidal ideation and retrospective reports of self-inflicted injury (SII) among adolescent girls, ages 13-17, with histories of depression (n = 28) or depression and self-harm (n = 29). Lower post-DST cortisol was associated with suicidal ideation and SII, over-and-above parent-reports and combined parent-/self-reports of internalizing and externalizing behavior. These findings are consistent with recent acquired capacity models of stress-related psychopathology in which hypothalamic-pituitary adrenal (HPA) axis function is altered through epigenetic/allostatic mechanisms among vulnerable individuals who incur adversity early in life.

Prediction of individual response to antidepressants and antipsychotics: an integrated concept

In both clinical trials and daily practice, there can be substantial inter- and even intraindividual variability in response--whether beneficial or adverse--to antidepressants and antipsychotic medications. So far, no tools have become available to predict the outcome of these treatments in specific patients. This is because the causes of such variability are often not known, and when they are, there is no way of predicting the effects of their various potential combinations in an individual. Given this background, this paper presents a conceptual framework for understanding known factors and their combinations so that eventually clinicians can better predict what medication(s) to select and at what dose they can optimize the outcome for a given individual. This framework is flexible enough to be readily adaptable as new information becomes available. The causes of variation in patient response are grouped into four categories: (i) genetics; (ii) age; (iii) disease; and (iv) environment (internal). Four cases of increasing complexity are used to illustrate the applicability of this framework in a clinically relevant way In addition, this paper reviews tools that the clinician can use to assess for and quantify such inter- and intraindividual variability. With the information gained, treatment can be adjusted to compensate for such variability, in order to optimize outcome. Finally, the limitations of existing antidepressant and antipsychotic therapy and the way they reduce current ability to predict response is discussed.

CNS drug development: lessons learned part 2. Symptoms, not syndromes as targets consistent with the NIMH research domain approach

This column is the second in a series exploring lessons for psychiatric drug development that can be learned from the development of 6 central nervous system drugs with novel mechanisms of action over the past 25 years. Part 1 presented a brief overview of the neuroscience that supported the development of each of these drugs, including the rationale for selecting their targets and indications. This column reviews specific principles involved in the development of these 6 drugs that have important implications for the future of psychiatric drug development. These include focusing on efficacy for a specific symptom or behavior rather than a broad syndrome, choosing a target in the brain with a specific behavioral output that is conserved from lower mammalian to human brains, and measuring outcomes based on behavioral phenomena that can be readily measured in an unambiguous parametric way. It is hoped that the Research Domain Criteria initiative of the National Institute of Health will promote research advances consistent with this model.

Crazy like a fox. Validity and ethics of animal models of human psychiatric disease

Animal models of human disease play a central role in modern biomedical science. Developing animal models for human mental illness presents unique practical and philosophical challenges. In this article we argue that (1) existing animal models of psychiatric disease are not valid, (2) attempts to model syndromes are undermined by current nosology, (3) models of symptoms are rife with circular logic and anthropomorphism, (4) any model must make unjustified assumptions about subjective experience, and (5) any model deemed valid would be inherently unethical, for if an animal adequately models human subjective experience, then there is no morally relevant difference between that animal and a human.

Comorbidities and continuities as ontogenic processes: toward a developmental spectrum model of externalizing psychopathology

Research on child and adolescent mental health problems has burgeoned since the inaugural issue of Development and Psychopathology was published in 1989. In the quarter century since, static models of psychopathology have been abandoned in favor of transactional models, following the agenda set by editor Dante Cicchetti and other proponents of the discipline. The transactional approach, which has been applied to autism, depression, self-injury, and delinquency, (a) specifies vulnerabilities and risk factors across multiple levels of analysis spanning genes to cultures, (b) identifies multifinal and equifinal pathways to psychopathology, and (c) transcends traditional disciplinary boundaries. However, as noted by Rutter and Sroufe (2000), specific mechanisms of continuity, discontinuity, and comorbidity of psychopathology must be identified if we wish to understand etiology fully. In this article, we present a model of early-onset externalizing behavior in which comorbidities and continuities are viewed as ontogenic processes: products of complex longitudinal transactions between interdependent individual-level vulnerabilities (e.g., genetic, epigenetic, allostatic) and equally interdependent contextual risk factors (e.g., coercive parenting, deviant peer group affiliations, neighborhood criminality). Through interactions across levels of analysis, some individuals traverse along the externalizing spectrum, beginning with heritable trait impulsivity in preschool and ending in antisociality in adulthood. In describing our model, we note that (a) the approach outlined in the DSM to subtyping externalizing disorders continues to obscure developmental pathways to antisociality, (b) molecular genetics studies will likely not identify meaningful subtypes of externalizing disorder, and (c) ontogenic trait approaches to psychopathology are much more likely to advance the discipline in upcoming years.

Irritable mood in adult major depressive disorder: results from the world mental health surveys

BACKGROUND

Although irritability is a core symptom of DSM-IV major depressive disorder (MDD) for youth but not adults, clinical studies find comparable rates of irritability between nonbipolar depressed adults and youth. Including irritability as a core symptom of adult MDD would allow detection of depression-equivalent syndromes with primary irritability hypothesized to be more common among males than females. We carried out a preliminary examination of this issue using cross-national community-based survey data from 21 countries in the World Mental Health (WMH) Surveys (n = 110,729).

METHODS

The assessment of MDD in the WHO Composite International Diagnostic Interview includes one question about persistent irritability. We examined two expansions of the definition of MDD involving this question: (1) cases with dysphoria and/or anhedonia and exactly four of nine Criterion A symptoms plus irritability; and (2) cases with two or more weeks of irritability plus four or more other Criterion A MDD symptoms in the absence of dysphoria or anhedonia.

RESULTS

Adding irritability as a tenth Criterion A symptom increased lifetime prevalence by 0.4% (from 11.2 to 11.6%). Adding episodes of persistent irritability increased prevalence by an additional 0.2%. Proportional prevalence increases were significantly higher, but nonetheless small, among males compared to females. Rates of severe role impairment were significantly lower among respondents with this irritable depression who did not meet conventional DSM-IV criteria than those with DSM-IV MDD.

CONCLUSION

Although limited by the superficial assessment in this single question on irritability, results do not support expanding adult MDD criteria to include irritable mood.

Rational use of multiple medications in medicine and psychiatry: a dimensional perspective

The authors propose a definition for rational multiple medication use (MMU). They then discuss how levels of diagnostic sophistication, ranging from symptomatic to syndromic to pathophysiologic to pathoetiologic, affect the ability to use multiple medications rationally. Based on this concept of diagnostic sophistication, MMU can be conceptualized dimensionally. Thus, MMU ranges from highly evolved and substantially evidence-validated approaches based on an understanding of the pathophysiological and pathoetiological nature of a disease (e.g., anti-retroviral treatment for HIV, multi-modal treatment of various malignancies), to those based on an understanding of the pathophysiology of an illness (e.g., various treatment combinations used to treat Parkinson's disease), to less evolved or less evidence-based medication combinations based on a syndromic diagnosis (e.g., such as are often used to treat bipolar disorder). By better understanding the principles involved in rational MMU, clinicians can optimize the treatment they provide their patients. (Journal of Psychiatric Practice 2013;19:54-61).

Persistence of stimulants in children and adolescents with attention-deficit/hyperactivity disorder

OBJECTIVE

To examine the persistence of three newly initiated stimulant preparations among Medicaid children and adolescents with attention-deficit/hyperactivity disorder (ADHD) diagnosis.

METHODS

A retrospective longitudinal claims analysis was conducted by using Medicaid analytical eXtract data of four states. The study focused on patients between 6 and 19 years of age with ADHD diagnosis and a stimulant prescription from January 2003 to December 2005. Stimulants were grouped into short-acting stimulants (SAS), intermediate-acting stimulants (IAS), and long-acting stimulants (LAS). Persistence was measured by totaling the number of days the patient remained on the index stimulant therapy from the index prescription date provided the refill gap between two consecutive stimulant claims was no more than 30 days. All the stimulant recipients were uniformly followed for 1 year (365 days). Survival time ratios (STR) were calculated by using accelerated failure time models to examine variation in index stimulant persistence for each stimulant class.

RESULTS

Among the 46,135 patients with ADHD continuously followed for 1 year, 8,260 were SAS users, 4,314 were IAS users, and 33,561 were LAS users. Children who received IAS medications had 4% shorter persistence (STR, 0.96 [95% confidence interval [CI], 0.93-0.98]) when compared with those who received SAS medications, whereas those who received index LAS medications had 29% longer persistence (STR, 1.29 [95% CI, 1.27-1.32]). Multivariate accelerated failure time models revealed that Blacks and Hispanics had consistently lower persistence than their counterparts. Foster care was positively associated with index stimulant persistence in the three stimulant types. Further, addition of another stimulant and other psychotropic medications significantly improved persistence of index stimulant in all three stimulant classes.

CONCLUSIONS

LAS had comparatively longer persistence than other stimulants. An understanding of demographic and clinical characteristics that influence treatment continuation can help improve stimulant persistence rates in ADHD.

Differentiating adolescent self-injury from adolescent depression: possible implications for borderline personality development

Self-inflicted injury (SII) in adolescence marks heightened risk for suicide attempts, completed suicide, and adult psychopathology. Although several studies have revealed elevated rates of depression among adolescents who self injure, no one has compared adolescent self injury with adolescent depression on biological, self-, and informant-report markers of vulnerability and risk. Such a comparison may have important implications for treatment, prevention, and developmental models of self injury and borderline personality disorder. We used a multi-method, multi-informant approach to examine how adolescent SII differs from adolescent depression. Self-injuring, depressed, and typical adolescent females (n = 25 per group) and their mothers completed measures of psychopathology and emotion regulation, among others. In addition, we assessed electrodermal responding (EDR), a peripheral biomarker of trait impulsivity. Participants in the SII group (a) scored higher than depressed adolescents on measures of both externalizing psychopathology and emotion dysregulation, and (b) exhibited attenuated EDR, similar to patterns observed among impulsive, externalizing males. Self-injuring adolescents also scored higher on measures of borderline pathology. These findings reveal a coherent pattern of differences between self-injuring and depressed adolescent girls, consistent with theories that SII differs from depression in etiology and developmental course.

Irritable mood and the Diagnostic and Statistical Manual of Mental Disorders

BACKGROUND

The terms 'irritable mood' and 'irritability' have been applied to describe and define a variety of different categories in the Diagnostic and Statistical Manual of Mental Disorders (DSM). More precise diagnostic terms and concepts are needed.

METHODS

A concise critical historical review of DSM categories characterized by irritability, anger, and aggression is presented followed by recommendations.

RESULTS

This analysis describes the broad ranging and imprecise use of the term irritability since the first DSM in 1952. A more age-appropriate and functional realignment of psychiatric categories linked to dysfunctional anger is suggested. Among other recommendations, this realignment would remove irritability as a problematic definer in the present DSM mood categories: expand oppositional defiant disorder to include adults; link the callous unemotional subtype of conduct disorder in adolescents to antisocial personality disorder; move intermittent explosive disorder to an appropriate category: and expand the term 'mood' to apply also to dysfunctional anger and anxiety.

CONCLUSION

The non-specific term 'irritability' commonly used in the DSM has had an adverse effect on diagnostic specificity and thereby on treatment. Dysfunctional anger is a major mood disorder which merits a more prominent and better defined representation in psychiatric nomenclature.

Psychotropic medication patterns among youth in foster care

CONTEXT

Studies have revealed that youth in foster care covered by Medicaid insurance receive psychotropic medication at a rate > 3 times that of Medicaid-insured youth who qualify by low family income. Systematic data on patterns of medication treatment, particularly concomitant drugs, for youth in foster care are limited.

OBJECTIVE

The purpose of this work was to describe and quantify patterns of psychotropic monotherapy and concomitant therapy prescribed to a randomly selected, 1-month sample of youth in foster care who had been receiving psychotropic medication. METHODS. Medicaid data were accessed for a July 2004 random sample of 472 medicated youth in foster care aged 0 through 19 years from a southwestern US state. Psychotropic medication treatment data were identified by concomitant pattern, frequency, medication class, subclass, and drug entity and were analyzed in relation to age group; gender; race or ethnicity; International Classification of Diseases, Ninth Revision, psychiatric diagnosis; and physician specialty.

RESULTS

Of the foster children who had been dispensed psychotropic medication, 41.3% received > or = 3 different classes of these drugs during July 2004, and 15.9% received > or = 4 different classes. The most frequently used medications were antidepressants (56.8%), attention-deficit/hyperactivity disorder drugs (55.9%), and antipsychotic agents (53.2%). The use of specific psychotropic medication classes varied little by diagnostic grouping. Psychiatrists prescribed 93% of the psychotropic medication dispensed to youth in foster care. The use of > or = 2 drugs within the same psychotropic medication class was noted in 22.2% of those who were given prescribed drugs concomitantly.

CONCLUSIONS

Concomitant psychotropic medication treatment is frequent for youth in foster care and lacks substantive evidence as to its effectiveness and safety.

Pharmacological aspects of the treatment of conduct disorder in children and adolescents

In recent years, the rates of psychosocial disorders in children and adolescents have increased, with behavioural manifestations of conduct disorder being one of the most common reasons for referrals to community psychiatrists. Childhood conduct problems are associated with a variety of psychiatric disorders in adult life that extend beyond antisocial behaviour. An increased awareness of the costs of conduct disorder to individuals, families and society has led to advancements in the pharmacological and nonpharmacological therapeutic modalities for this disorder. Despite this, patients with conduct disorder are difficult to treat as the patterns of maladaptive behaviours they exhibit are diverse and can vary as a function of age and sex. A multidisciplinary approach to the treatment of conduct disorder, which includes behavioural parent training, interpersonal skills training, family therapy and the use of psychotropic agents targeted at a particular cluster of symptoms, can increase the overall effectiveness of each of the applied interventions. Aggression, hyperactivity, impulsivity and mood symptoms are the most sensitive proximal targets. Evidence suggests that antipsychotics, antidepressants, mood stabilisers, antiepileptic drugs, stimulants and adrenergic drugs can be well tolerated and effective therapeutic options for individuals with conduct disorder and comorbid psychiatric conditions. However, the most successful therapeutic outcomes are likely to be achieved by combining the current advances in psychopharmacology with behavioural and psychosocial interventions, aimed at modifying the excessive patterns of maladaptive behaviours observed in conduct disorder.

Pharmacogenomics, informatics, and individual drug therapy in psychiatry: past, present and future

The modern era of psychopharmacology began in the 10 year period from the late 1940s to the late 1950s. During this period, the first antidepressants, antipsychotics, anxiolytics and mood stabilizers were all discovered. In the 1960s, the pharmacology of these drugs was elucidated and theories about the mechanisms of action proposed. In the 1970s and 1980s, new, more selective compounds were developed based on improved structure-activity relationships derived from in vitro receptor binding studies and animal models. These compounds entered clinical testing in the 1980s and began to be marketed in the late 1980s and 1990s. All of these agents were approved to treat psychiatric syndromes which are conditions defined by a cluster of signs and symptoms. None of these agents was developed based on an understanding of the pathophysiology of the illnesses being treated. None of these agents are curative and virtually all have limited clinical efficacy. In the earliest days of the modern era, there were few drugs available to combine and many had such broad actions that they were often marginally tolerated or unsafe when used in combination (tricyclic antidepressants and monoamine oxidase inhibitors). With the advent of more medications, the frequency and extent of polypharmacy has exploded. In addition to simply having more drugs from which to select with different pharmacological profiles, many newer medications are also more selective in their pharmacological actions and thus are often better tolerated and safer when used in combination. In addition, there is the concern that the trade-off for more selective pharmacology may have been better tolerability at the expense of reduced efficacy, which clinicians then compensate for by using more medications in combination. For all of the above reasons, polypsychopharmacology has been present from the beginning of the modern era of psychopharmacotherapy and continues to be the rule rather than the exception. In fact, the frequency and the complexity of such polypsychopharmacology are both enormous and increasing. The percentage of patients being discharged from the Biological Branch of the National Institute of Mental Health on more than three psychiatric medications increased more than ten times between 1974-79, and 1990-95. The majority of patients seen in the Veterans Administration Medical System in the United States are on unique combinations of medications and the frequency and complexity of such polypharmacotherapy is increased in patients on psychiatric medications. Throughout the modern era, there have been attempts to determine whether there are populations of patients selectively responsible to specific agents (e.g. serotonin versus norepinephrine reuptake inhibitors). However, no compelling data have so far emerged. Instead, clinicians generally resort to combining drugs on the basis of symptoms such as psychosis and depression or anxiety and depression. Science has primarily informed the clinician about safety concerns rather than efficacy concerns when using such combinations. That will change in the future with a better understanding of the pathophysiology of psychiatric illnesses which in turn will lead to improved therapies and the potential for more rationally derived combination treatments.

Psychopharmacology of conduct disorder: current progress and future directions

Behavioural manifestations of conduct disorder (CD) among children and adolescents are one of the most common referrals to community psychiatrists. Patients with CD are difficult to treat. The patterns of maladaptive behaviours they exhibit are diverse and can vary as a function of age and gender. Although different pharmacological interventions have been reported as potentially promising options in the treatment of CD, no medication has yet received a formal approval from the licensure authorities, either in the US or Europe. This article reviews efficacy results and associated adverse effects from selected clinical trials that have the strongest outcome evidence for the treatment of CD in children and adolescents. Critical issues in the effectiveness of the evidence-based pharmacotherapy for CD are raised and future directions of the psychopharmacology of CD are examined.