Psychotropic Use Among Youths With Intellectual and Developmental Disabilities

Youths (including transition-age youths) with intellectual and developmental disabilities are particularly vulnerable to excessive use of psychotropic medications (1–4). These youths commonly present with challenging, aggressive, or disruptive behaviors (5, 6), along with multiple psychiatric diagnoses, and they often receive psychotropic medications (7). About 2.8% of youths in the United States have intellectual and developmental disabilities and co-occurring behavioral or mental health presentations (8–10). The overall rate of psychiatric diagnoses among youths with intellectual and developmental disabilities is about 30%–50% (9, 11), including high prevalence rates of depression, attention-deficit hyperactivity disorder (ADHD), and anxiety disorders (10). Psychiatric hospitalizations and emergency department visits are common (12–18).

To manage the challenging behaviors often associated with these conditions, prescribers frequently use polypharmacy, antipsychotics, and mood-stabilizing anticonvulsants (3, 19–22), practices that may not control behaviors (23) and commonly produce serious adverse effects (24–26). In fact, youths with intellectual and developmental disabilities are more likely than other youths to experience adverse effects (27–31), which may paradoxically cause or contribute to challenging behaviors (32–34).

Researchers, policy makers, parents, and advocates have voiced concerns regarding prescription of psychotropic medications to youths with intellectual and developmental disabilities. The evidence on the effectiveness and safety of such use is limited (3, 35), including a lack of long-term treatment studies (35). The U.S. Federal Drug Administration (FDA) has approved risperidone and aripiprazole for managing irritability associated with autism spectrum disorder (ASD) (23, 36), but other medications and indications for this population have minimal evidence for effectiveness, and their long-term effects on development are unknown. Practices that raise concern include the polypharmacy, off-label use, and overuse of antipsychotics and anticonvulsants (23, 35, 37, 38). The limited available research on these practices has focused on adults with intellectual and developmental disabilities rather than on youths (39, 40).

Few previous studies have assessed the use of psychotropic medications among youths with intellectual and developmental disabilities. In a study of 176 outpatient adolescents with intellectual disability in Australia, 20% received psychotropic medications, <1% received psychotropic polypharmacy, and psychotropic medication use was associated with male gender and behavioral problems (41). Among 472 adolescents institutionalized with mild intellectual disability in the Netherlands (42), 30% received psychotropic medications. Of those with mental health or behavioral problems, 35%–50% received psychotropic medications, 15% received antipsychotics, and about 10% received treatment with two or more psychotropic drug classes. Age, male gender, and behavioral problems were all associated with psychotropic medication use (42). A study that included 141 Medicaid-covered children with intellectual and developmental disabilities and psychiatric diagnoses in the United States found that 37%–40% received antipsychotics, and 25%–29% received mood stabilizers (3). A study of 60 children with intellectual and developmental disabilities receiving Medicaid in Kansas found that 17%–37% received antipsychotics and that psychotropic medication use was associated with having a psychiatric diagnosis (43).

Youths with intellectual and developmental disabilities represent a population with complex conditions. Studying a large group of youths with intellectual and developmental disabilities and co-occurring challenging behaviors or psychiatric diagnoses referred to START, here we examined the frequency and correlates of the following prescribing practices: polypharmacy, use of antipsychotics, and use of mood-stabilizing anticonvulsants in the absence of seizure disorder.

Methods

We examined the prevalence of psychotropic medication prescribing practices in a national study group of at-risk children and transition-age adults. The Committee for the Protection of Human Subjects at the Geisel School of Medicine at Dartmouth approved and monitored the study following Declaration of Helsinki standards.

Participants

The Center for Systematic, Therapeutic, Assessment, Resources, Treatment (START) Services at the University of New Hampshire Institute on Disability promotes effective services and supports for people with intellectual and developmental disabilities nationally (44). START programs provide crisis support, consultation, training, and outreach to individuals, families, and systems of care. At intake, START coordinators gather baseline data that are entered into the START information reporting system. The deidentified data provide information and feedback to administrators, policy makers, and practitioners.

For this study, we included data for children (between ages 5 and 17 years) and transition-age young adults (ages 18–21 years) enrolled in START in 10 U.S. states from January 1, 2013, to July 15, 2017. Transition-age young adults with developmental disabilities are eligible for school-based services through age 21 and remain vulnerable in many of the same ways as are minors. The sample for this study included 1,333 youths with intellectual and developmental disabilities and co-occurring challenging behaviors or psychiatric diagnoses. We evaluated prescribing practices at the time of intake in relation to 11 baseline characteristics.

Measures

Demographic characteristics, psychiatric diagnoses, and history of psychiatric hospitalizations.

Demographic characteristics included age, sex (male or female), race-ethnicity (White or other), and living situation (group home or other). Psychiatric diagnoses included the number of psychiatric diagnoses and ASD status (yes or no) at intake. History of psychiatric hospitalizations indicated any psychiatric hospitalization in the year before enrollment.

Presenting problems and severity of intellectual impairment.

Presenting problems included the presence of aggressive behavior, including physical or verbal aggression, property destruction, or threats, at intake. Severity of intellectual impairment, which was based on records reviewed at intake, included normal intelligence, borderline or mild impairment, moderate impairment, and severe or profound impairment.

Aberrant behavior.

Aberrant behavior was assessed with the Aberrant Behavior Checklist (ABC) (45, 46), completed by the primary caregiver at intake. The ABC includes several subscales, and we used the 15-item irritability subscale, which rates temper outbursts, negative mood, aggression, and self-harm behavior (45–48). Caregivers rate the items on a 4-point Likert scale of severity, ranging from 0 (“not at all a problem”) to 3 (“problem is severe in degree”) (46, 47).

Funding.

We obtained information on funding for care through records and caregivers at intake. We included whether patients received the Medicaid home and community-based services waiver (designed to provide assistance to the youths and their families in their home or community), Medicaid, private insurance, and a combination of funding sources.

Prescribing practices.

The START information reporting system database includes the numbers of stimulants, antidepressants, antianxiety medications, first- and second-generation antipsychotics, anticonvulsants, and sedative hypnotics prescribed to each participant at intake. “Polypharmacy” was defined as the concurrent use of three or more psychotropic drugs. “Use of an antipsychotic medication” indicated at least one prescribed first- or second-generation antipsychotic medication. “Anticonvulsant in the absence of seizure disorder” indicated anticonvulsants or mood stabilizers used to target irritability and challenging behaviors (35, 49).

Statistical Analysis

We used Poisson regression with robust variance (50) to estimate the relative risk for polypharmacy, antipsychotic medication use, and antiepileptic use without a seizure disorder associated with demographic and diagnostic factors, including interactions between ASD and irritability, age, and the presence of psychotic disorders. First, we constructed models including only single measures. Then, we compared each coefficient with that factor’s coefficient in a full model for a given outcome containing all other factors. If the coefficient differed by at least 10%, we considered the association between it and the outcome to have been confounded by the other characteristics. We believed it likely that age would confound many of the factors present in this analysis and elected to treat age as a control variable and not as a primary factor of interest. Therefore, we parameterized it as a continuous variable instead of converting it to a categorical variable to preserve its information content and maximize its utility as a control variable.

Although this approach made it difficult to assess the potential association of the important youth-adulthood age dichotomy with polypharmacy, the use of a continuous age variable scaled to describe the risks associated with 10-year increases in age captured an element of that dichotomy and maintained our ability to detect any overall trends in the association between age and polypharmacy. We made several decisions designed to reduce the number of statistical tests, including reducing the number of categories within variables and testing interactions of key predictors with ASD instead of conducting a fully stratified analysis. We also chose to use only one of five ABC subscale scores in our analysis, selecting irritability to test for its interaction with ASD. Irritability was also the subscale most consistently correlated with the other subscale scores (Pearson correlation coefficients >0.4). Use of only one ABC subscale score also addressed the expansion of standard errors and potential instability of estimated coefficients associated with collinearity. We used StataSE, version 14.1, and corrected for type I error inflation due to multiple tests with a Bonferroni correction based on 18 tests for each of three potential outcomes, yielding 54 tests and a corrected α=0.001.

Results

Table 1 shows the baseline characteristics of the study group of 1,333 youths, including demographic and diagnostic characteristics. Approximately three-quarters of the youths were male, most were White, nearly one-quarter were diagnosed as having normal-to-borderline intellectual functioning, and most lived in either their family home or in a group home. Most presented with aggression (e.g., physical, verbal, property destruction, and threats), and more than one-third had psychiatric hospitalizations or emergency department visits in the year before START intake. The majority had a psychiatric diagnosis, and approximately one-half had multiple psychiatric diagnoses. The most common diagnoses were ADHD, ASD, and depression.

Table 2 shows the prevalence of psychotropic medication use. The majority received at least one psychotropic medication (N=1,139, 86%), and 55% (N=733) received three or more. Furthermore, most received antipsychotic medications (N=863, 65%), and about one-third received anticonvulsants in the absence of a seizure disorder (N=432, 32%).

Table 3 shows the independent associations of various factors with polypharmacy, antipsychotic medication use, and anticonvulsant use without a seizure disorder. For each outcome, the risk ratios (RRs) for each potential characteristic were adjusted for the effects of all other characteristics. We found extensive confounding by other potential explanatory factors of the relationships between individual factors and the assessed outcomes. Age was statistically significantly associated with an increase in polypharmacy (RR=1.38, p<0.001) and with anticonvulsant use in the absence of a seizure disorder (RR=2.05, p<0.001). Number of diagnoses significantly increased the risk for polypharmacy (RR=1.10, p<0.001). Having a psychiatric hospitalization in the past year was associated with polypharmacy (RR=1.18, p=0.001), antipsychotic medication use (RR=1.21, p<0.001), and anticonvulsant use in the absence of a seizure disorder (RR=1.34, p=0.001).

Patients living in group homes were significantly more likely to be prescribed antipsychotic medications than those not living in group homes (RR=1.26, p<0.001). Several associations approached, but did not cross, our chosen statistical significance threshold, yielding a p<0.01 but >0.001. These associations included the number of psychiatric diagnoses and the presence of a psychotic disorder with the use of antipsychotic medication, and the ABC irritability subscale score with polypharmacy, antipsychotic medication use, and anticonvulsant use without a seizure disorder.

Discussion

The findings in this study document high rates of polypharmacy, antipsychotic use, and anticonvulsant use in the absence of a seizure disorder among children and transition-age youths with intellectual and developmental disabilities and co-occurring challenging behaviors and psychiatric diagnoses referred to START. A START referral indicates that the system of support views the youth to be at risk for mental health crises. Most participants received psychotropic medications and polypharmacy. Approximately two-thirds were taking antipsychotics, and one-third were taking anticonvulsants in the absence of a seizure disorder. Psychiatric hospitalization in the past year, older age, number of psychiatric diagnoses, and living in a group home increased the odds of receiving one or more of these identified prescribing practices. These variables are not strong predictors of the identified prescribing practices, and more research is needed.

Our study did not find differences between the groups with and without ASD for any of the identified prescribing practices, including antipsychotic use. The two groups were similar in demographic characteristics, clinical characteristics, and medication patterns. Given that the FDA has approved risperidone and aripiprazole for treating irritability associated with ASD, one may have expected to find higher rates of antipsychotic medication use among individuals in the ASD group. Another study of youths with intellectual and developmental disabilities and challenging behaviors also did not find an association between psychotropic medications and ASD after adjusting for confounding factors (41). The lack of an association of ASD with psychotropic or antipsychotic medications in our and the previous study may be explained by the fact that individuals with or without ASD in our study were struggling with challenging behaviors and that psychotropic medications were used to address these challenging behaviors.

The results of this study reveal community-based prescribing practices for youths with intellectual and developmental disabilities with co-occurring challenging behaviors or psychiatric diagnoses before entering START services. These youths struggle with significant behavioral and mental health presentations, prompting the referral to START services. The association between increasing age and polypharmacy suggests that these individuals may have received more psychotropic medications over time. Similarly, other studies have found that youths with intellectual and developmental disabilities receive more psychotropic medications over time without discontinuation of medications that are ineffective (51, 52).

The association between polypharmacy and number of psychiatric diagnoses suggests that individuals who experience more severe difficulties are treated with more medications, although it is also possible that prescribers add diagnoses to justify adding medications. The association between number of psychiatric diagnoses and polypharmacy has also been reported for adults with intellectual and developmental disabilities (39). Similarly, the association between psychiatric hospitalization and psychotropic polypharmacy, antipsychotics, and anticonvulsants may also indicate that individuals with more severe difficulties are treated with more medications.

Psychiatric hospitalization may be a pathway to receiving psychotropic polypharmacy, antipsychotics, and anticonvulsants (53). Other studies have found elevated rates of psychiatric hospitalizations (1%–11%) and emergency department visits (11%–22%) for youths with intellectual and developmental disabilities (12, 14, 18). More than one-third of our study group experienced a psychiatric hospitalization within the year before their START intake; the participants in our study had higher rates likely due to their co-occurring challenging behaviors and psychiatric diagnoses. A study of adults with intellectual and developmental disabilities in Canada found that individuals with comorbid psychiatric diagnoses had higher rates of psychiatric hospitalization (31%) and antipsychotic use than did those without a comorbid psychiatric diagnosis (4.2%) (54).

Antipsychotic use associated with living in a group home has also been found in other studies of adults with intellectual and developmental disabilities (54–56). Others have hypothesized that prescribing in group homes may be affected by external factors such as staffing and environmental characteristics (54, 57, 58). The youths in the present study may have struggled with higher levels of concerning behaviors, which led to living in a group home; inpatient psychiatric hospitalization; and higher rates of polypharmacy, antipsychotics, and anticonvulsant use without a seizure disorder. However, one may hypothesize that despite the polypharmacy and antipsychotic and anticonvulsant medication uses, the youths continued to struggle with challenging behaviors and psychiatric diagnoses and were therefore referred to START services. Certainly, we need further strategies to support these vulnerable youths with intellectual and developmental disabilities who experience co-occurring challenging behaviors or psychiatric diagnoses.

Some support strategies to consider include a full biopsychosocial formulation, evidenced-based psychotherapeutic interventions, consultation with specialists caring for individuals with intellectual and developmental disabilities, collaborative practices, and systematic responses (22, 39, 44). To avoid polypharmacy, providers prescribing psychotropic medications to youths with intellectual and developmental disabilities should consider a slow, step-wise approach when initiating and titrating psychotropic medications and coordinating care with the child’s behaviorist or therapist to provide behavioral data or collateral information (59, 60). The rates of polypharmacy and antipsychotic medication use documented in START intake data were higher than those reported in most other studies of youths with ASD and adults with intellectual and developmental disabilities (3, 39, 55, 61), despite these studies also including individuals with co-occurring challenging behaviors or psychiatric diagnoses (41, 42). This finding may indicate that more high-risk patients receive START referrals.

Several potential limitations of this study warrant mention. First, our data came from a group of youths with intellectual and developmental disabilities struggling with co-occurring challenging behaviors or psychiatric diagnoses considered to be at high risk for crisis service use. The results therefore may not generalize to all youths with intellectual and developmental disabilities, representing only a subgroup with co-occurring challenging behaviors or mental health needs. Second, although polypharmacy, antipsychotic use, and anticonvulsant use are concerning practices, we could not determine the efficacy for particular youths from cross-sectional data, because the prescribing practices predated the referral to START. Third, because our data came from START intakes, we could not assess changes to medication regimens over time.

Fourth, we had only limited information on provider profile and other sociodemographic variables of the youths and families that may have affected prescribing. Our choice to treat age as a control variable and not parameterize it to directly address the potential effect of youth versus adulthood on polypharmacy prevented us from addressing this important influence of age on prescribing. The strength of age in this analysis indicates that this research question remains important. Fifth, the RRs were small; thus, the identified predictors were not strong predictors of the identified prescribing practices. Despite these limitations and to our knowledge, our study is the largest cross-sectional study to evaluate and characterize psychotropic medication use among children and transition-age adults with intellectual and developmental disabilities with challenging behaviors and co-occurring psychiatric diagnoses.

Future research on this population should be performed longitudinally, examining the biological and cognitive effects of long-term psychotropic medication use on individuals with intellectual and developmental disabilities within this cohort. It is critical that research explore the pathway toward polypharmacy, with particular attention to further understanding about who is at risk and how the prescribing practices identified here come about. In addition, we recommend closer study regarding psychotropic medication use among very young children with intellectual and developmental disabilities.

Further works needs to examine regional trends, provider profiles, sociodemographic variables, and other possible contributors to the prescribing of psychotropic medications among youths with intellectual and developmental disabilities. It will be important to further examine whether this prescribing is reflective of U.S. clinical practices by comparing this cohort with another comparable sample of individuals in the United States. Finally, future research should study the use of psychosocial interventions to avoid or reduce polypharmacy antipsychotic medication use and anticonvulsant use in the absence of seizure disorders among these patients.

Conclusions

Polypharmacy, antipsychotic medication use, and anticonvulsant use in the absence of seizures were found to be common prescribing practices to treat youths with intellectual and developmental disabilities with co-occurring challenging behaviors or psychiatric diagnoses referred to START. Older age, number of psychiatric diagnoses, living in a group home, and recent psychiatric hospitalization were significantly associated with these prescribing practices. Future research should assess strategies to further support youths with intellectual and developmental disabilities and to reduce these potentially harmful prescribing practices.