NADD Bulletin Volume VII Number 1 Article 1

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The Effect of Psychotropic Medications on Social Skills in Persons with Profound Mental Retardation

Jay W. Bamburg, Ph.D., Johnny L. Matson, Ph.D., & William Drew Gouvier, Ph.D.


People with mental retardation exhibit a large number of behavioral excesses and deficits and the full range of psychopathology. As a result, interventions involving psychotropic medications are widely used in the population. Few researchers have examined the effect of psychotropic interventions on the total behavioral repertoire. Typically, only the suppression of symptoms or maladaptive behaviors are examined without considering the manner in which medications may alter the positive behavioral repertoire or cause deleterious side effects. This study aimed to address medication effects on the positive behavioral spectrum by examining the effects of these interventions on social and adaptive skills. Subjects were placed in 1 of 5 groups that corresponded to their current medication regimes. Individuals who received traditional antipsychotics, atypical antipsychotics, and multiple medications had significantly less social and adaptive skills than did individuals receiving anti-epileptic medications and experimental controls. The same groups (traditional antipsychotics; atypical antipsychotics; multiple medications) demonstrated a significant decline in social and adaptive skills among participants receiving the particular medication regime a minimum of three years. Finally, analyses of demographic variables did not delineate significant differences between groups in terms of actual demographic variables or in social and adaptive skills. Clinical implications of this research are discussed with an eye for providing enhanced care for persons with developmental disabilities.


Persons with mental retardation exhibit the full range of psychopathology found in populations without developmental disabilities and do so with higher prevalence rates (Borthwick-Duffy, 1994). Additionally, persons in this population often exhibit behavioral excesses or deficits that are dangerous to themselves, caretakers, or other clients in their proximity. As a result, treatment of these conditions has long been the job of mental health professionals working in the field. Treatments have generally been taken from one of two genres; behavioral or pharmacological (Baumeister & Sevin, 1990). Behavioral treatments have been well documented as effective in the research literature dating as far back as the late 1950s. The same, however, cannot be said for pharmacological treatments. Despite the recurrent themes in treatment literature and mental retardation, pharmacological treatments are far more frequent than traditional psychological therapy or behavioral protocols (Baumeister, Todd, & Sevin, 1993).


The research that exists concerning the deleterious effects of psychotropic medications on social and adaptive functioning is also lacking (Matson et al., 2000). However, some researchers do indicate the importance of monitoring the effects of these medications on adaptive functioning. For example, it is known that the traditional antipsychotic medications (Thorazine™, Haldol™) have sedating effects and, in the long term, can alter central nervous system functioning and neurotransmitter release, receptor sites, and reuptake. Alteration of central nervous system functioning often leads to long-term side effect conditions such as tardive and other dyskinesias, which can inhibit learning. These short and long term changes can certainly impact the manner in which an individual engages in social and adaptive activities, as an individual who is disengaged, or in perpetual, disturbing motion, is less likely to display a wide array of socially appropriate skills than a peer without these conditions (Singh, Landrum, Ellis, & Donatelli, 1993).

Much of the same is true for the newer atypical antipsychotics (Risperdal™, Zyprexa™), medications created to affect positive and negative symptoms of psychoses while having cleaner side-effect profiles. These medications have similar sedating effects as the traditional antipsychotics, may alter learning, and, with long term use, can alter functioning of the central nervous system to the point of enduring side-effects (Sperner, Czeipek, Gaggl, Geissler, Speil, & Fleischhacker, 1998). However, these medications are said to cause fewer long-term side effects and have properties similar to the selective serotonin reuptake inhibitors, which should cause an individual to be less withdrawn, have a more appropriate affect, and be more socially appropriate and engaging (Rubin, 1997). Perhaps individuals receiving atypical antipsychotics would have a larger social repertoire than those receiving traditional neuroleptic medications (Purdon, Lit, Labelle, & Jones, 1994).


The anti-epileptic drugs (AEDs; Depakote™; Tegretol™) can also alter the manner in which an individual learns and functions socially and adaptively, although medications in this class less frequently alter these social and adaptive skills than the more potent antipsychotic class (Ruedrich, Swales, Fossaceca, Toliver, & Rutkowski, 1999). The AEDs have sedating effects that are dose dependent and can adversely alter social and adaptive skills (Ruedrich et al., 1999), especially when used at levels sufficient to obtain anticonvulsant effects. However, most persons receiving this class of medication are taking smaller doses for behavior control and do not suffer from the sedating effects. These medications can also have a large number of gastrointestinal, cardiovascular, hematologic, and genitourinary effects (Matson et al., 2000). The result of any one or combination of these defects can be poor physical health which can directly inhibit an individual's social and adaptive functioning. Finally, long term use of these medications can cause behavior altering side-effects. While these side-effects are different from the movement disorders and dyskinesias often associated with neuroleptic medications, agitation and aggression are often associated with long-term AED use. As expected, individuals who are often agitated or aggressive towards peers, family, or care-givers will exhibit less measured social and adaptive skills (McCord, Tremblay, Vitaro, & Desmarais-Gervais, 1994).

The use of multiple medication classes for treatment of one individual is also readily seen in persons with mental retardation. While medication regimes vary, the most popular interclass polypharmacy tends to involve the use of a typical or atypical antipsychotic medication in conjunction with another medication for behavior control. It makes sense that persons receiving polypharmacy of this type may experience multiple short and long-term side effect profiles and sedation effects as seen singly in persons receiving only one medication. However, the exact manner in which these medication interact and the resulting social and adaptive skills profiles are unknown and have yet to be examined closely in research.


  There is currently a paucity of research evaluating the use of psychotropic medications with persons with mental retardation which has, in turn led to the vast overuse of medication in the population. These findings are probably due to a number of factors. First, psychotropic medications are the product of drug companies and their use is supported by a large and powerful industry. Research that opposes the efficacy of a particular medication or reports the medication's deleterious effects often is not published or, if published, is not widely read by treating professionals (Baumeister, Todd, & Seven, 1993). Second, the use of the medical model of treatment is still widespread for persons with mental retardation. In this model, most problems are referred to a physician with the expectation that a prescription "pill" will alleviate the problem. While this method of treatment is effective with some medical or psychiatric conditions, it is certainly not set in stone for all behavior problems or symptoms. The end result is overuse or misuse of medication. Third, a shift in attitude concerning treatment of debilitating conditions has occurred in the past years. Behavioral treatments are often viewed by certain national advocacy groups as inhumane; therefore, any research pertaining to behavioral techniques is held to a higher degree of scientific rigor and then, many times, not accepted as efficacious (Singh et al., 1993). Drug treatments, on the other hand, involve only giving a pill and are viewed as more humane and "normalized" (Wolfensberger, 1970). Finally, the Food and Drug Administration (FDA) harbors a group of medications known as "orphan" drugs; that is, drugs that are for the treatment of conditions that are specific or prevalent to a small group or population. Due to a lower demand for these medications, the companies producing the drugs allot insufficient funds for proper evaluation of their effects. Although persons with mental retardation receive far more research attention than they did 30-50 years ago, they are still somewhat of an "orphan" group.


This study represents an attempt to identify relationships between psychotropic medication use and resulting social skills excesses and/or deficits. While a few studies do include measures of collateral behaviors, this study is the first to systematically focus on social skills and how psychotropic medication effects them. It is hoped that identifying the adverse effects on social skills caused by inappropriate use of psychotropic medication will alert clinicians to this potential problem. Next, the identification of such profiles should change the methods of assessment used by clinicians by adding a broader scope of effected behaviors. That is, we hope to alert clinicians to pay more attention to the assessment of collateral behaviors in persons with mental retardation versus suppression of maladaptive behaviors alone. Finally, it is hoped that the findings of this research will stimulate further investigation into the effects of psychotropic medications on persons with developmental disabilities.



One hundred participants who reside in developmental centers in Louisiana were studied. Participants were classified as functioning in the profound range of mental retardation and were chosen and grouped based on the type of psychotropic medication they were receiving. Five groups of 20 subjects each were studied: 1) persons receiving only a traditional antipsychotic medication (e.g., Haldol™, Mellaril™); 2) persons receiving only an atypical antipsychotic medication (e.g., Risperdal™, Zyprexa™); 3) persons receiving only a mood stabilizing medication (e.g., Depakote™, Tegretol™); 4) persons on multiple medications (antipsychotic medication and a medication for behavior control); and, 5) controls receiving no medication. Subjects were matched on demographic characteristics and behavior problems to equate group means in these areas. While medication history was an important variable in this equation, subjects were not matched on this variable due to difficulty in obtaining accurate histories. However, to help account for this variable, all subjects included in the medication groups had at least a three year history of psychotropic medication use with the current medication regime.



Matson Evaluation of Social Skills in Persons with Severe Retardation (MESSIER): The MESSIER is an 85-item questionnaire designed to assess social strengths and weaknesses in people with severe and profound mental retardation (Matson, 1995). The MESSIER items are grouped into six clinically derived subscales: positive verbal, positive nonverbal, positive general, negative verbal, negative nonverbal, and general negative. Each item is rated on frequency using a 4-point Likert scale: (0) never occurs, (1) rarely occurs, (2) sometimes occurs, and (3) often occurs. Endorsed items are transcribed onto a scoring profile under their respective subscales. This method allows the clinician to examine scoring patterns across subscales. The MESSIER is completed for all clients in the developmental centers as part of a larger functional assessment package.

Vineland Adaptive Behavior Scales (VABS): The VABS, a measure of adaptive skills that consists of 4 domains, 11 subdomains, an adaptive behavior composite, and a maladaptive behavior domain was used to measure adaptive skills. The questions focus on social skills and maladaptive behaviors and are listed in the order they should be developmentally achieved. Each item on the VABS can receive a score of 2 (yes, usually), 1 (sometimes or partially), 0 (no, never), N (no opportunity), or DK (don't know). Reliability coefficients for internal consistency, interrater, and test-retest estimates are high for the scale, averaging in the .80s and .90s. Measures of construct validity have consistently resulted in coefficients above .70 (Sparrow, Balla, & Cicchetti, 1984).



Direct care staff who had worked with the clients in question for at least six months were used as informants for the administration of the MESSIER and the VABS. Master's level staff psychologists and graduate students in a Ph.D. program in clinical psychology administered the measures to direct care staff as part of a functional assessment battery that is completed yearly. Each examiner received training sessions on the administration and scoring of the MESSIER and the VABS. Administration of the measures required approximately 50 minutes.

Two measures of social and adaptive skills were obtained for each subject. The first measure, Time 1, included measures of social and adaptive skills obtained from a standard psychological assessment conducted in 1997. The second measure, Time 2, included measures of social and adaptive skills obtained from psychological assessments completed in 2000. Obtaining two measures of social and adaptive skills for each individual allowed for a more comprehensive, longitudinal evaluation of drug effects on social and adaptive behavior. Once all pertinent information was collected, the following manipulation checks and hypotheses were generated and the resulting analyses conducted.


Demographic variables were analyzed to evaluate possible differences between groups with regard to age, race, gender, deafness, blindness, and ambulation vs. non-ambulation. A Multivariate Analysis of Variance with group membership as the independent variable and demographics as the dependent measures failed to yield significant effects (Wilks' Lambda F (7, 89) = .474, p = .990). These findings were expected given the matching process utilized in group formulation. Means and percentages for demographic variables are reported in Table 1.

Demographic variables were analyzed in relation to positive subscale scores on the MESSIER (positive verbal, positive nonverbal, general positive) and the behavioral subdomains of the Vineland Adaptive Behavior Scales (communication, daily living, socialization). A multivariate analyses of variance with demographic variables as the independent variables and the social and adaptive scores as the dependent variables was utilized for the analyses. No statistically significant differences emerged on MESSIER subscale scores or VABS subdomains as a function of age, race, gender, deafness, blindness, or ambulation. Results appear in Table 2.

Next, data from the MESSIER subscales and VABS subdomains were analyzed by use of MANCOVA. Two observations were obtained for each social and adaptive category; the Time 1 measure was obtained from psychological testing conducted in 1997 and Time 2 measure from data collected during yearly assessment from 2000. Group membership in each of the five drug classes served as the independent variables in this analyses, and the Time 2 measures of social and adaptive skills were the dependent measures. The Time 1 measures of social and adaptive skills were utilized as covariates in the analyses to obtain a greater degree of experimental control. The multivariate analyses yielded significant results, (Wilks' Lambda F (6, 90) = 6.29, p < .001), indicating significant differences in measured social and adaptive skills between drug classifications.

ANOVAs with Tukey post-hoc tests were then conducted to identify specific patterns of significant relationships between groups on measured social and adaptive skills. Analyses indicated significant results between groups on the positive verbal subscale (F (4, 95)= 6.6, p < .001), positive nonverbal subscale (F {4, 95} = 11.5, p < .001), general positive subscale (F {4, 95}= 19.2, p < .001), communication subdomain (F {4, 95}= 4.6, p = .002), daily living skills subdomain (F {4, 95}= 3.6, p = .009), and the socialization subdomain (F {4, 95}= 13.7, p <.001). Means for social and adaptive measures by group membership are found in Table 3.

Summarizing post-hoc tests, persons receiving traditional antipsychotic medications, atypical antipsychotic medications, and drug regimes including an antipsychotic medication and a mood stabilizer demonstrated fewer measured social and adaptive skills than persons on anti-epileptic medications or experimental controls. Additionally, persons receiving anti-epileptic medications demonstrated less measured positive nonverbal skills, general positive skills, and socialization subdomain skills than experimental controls. Overall, these findings indicate that medication regimes have a significant impact on social and adaptive behaviors.

The final group of analyses sought to investigate differences in measured social and adaptive skills, over time, as a function of membership in each drug group. A repeated measures MANOVA with group membership as the independent variable was used to investigate the hypothesis. The dependent variables were comprised of two levels each of the positive subscales from the MESSIER and adaptive subdomains of the VABS. The Time 1 measures of social and adaptive behavior were obtained from psychological testing conducted in 1997 and Time 2 measures from data collected during yearly assessment from 2000. Means for each level of social and adaptive behavior, by group membership, are reported in Table 4.

The multivariate portion of the analysis yielded significant differences between levels (Time1; Time2) on measured social and adaptive skills (Wilks' Lambda F{4, 20} = 2.71, p < .001). Next, repeated measures analyses with Tukey post-hoc tests were conducted to establish which groups contained significant differences and the variables where the differences occurred. The repeated measures ANOVA, with sphericity assumed, yielded significant within-subjects effects, (F{5, 20}= 3.13, p < .001). Post-hoc tests indicated significantly less social and adaptive skills at Time 2 (psychological assessment from 2000) for individuals receiving traditional antipsychotic medications, atypical antipsychotic medications, and multiple medications (antipsychotic medication and a mood stabilizer). Interestingly, scores for individuals receiving anti-epileptic medications and experimental controls remained mostly stable over the same period of time.


A relationship appears to exist between medication regimes and social and adaptive skills in persons with profound mental retardation. Additionally, persons in this sample experienced a decrease in social and adaptive behavior as a function of time and medication regime. Individuals receiving medication regimes consisting of traditional or atypical antipsychotic medications had consistently less social and adaptive skills than those receiving other medications or experimental controls. The same groups also experienced decreases in social and adaptive behavior after receiving particular medications a minimum of three years. Lastly, demographic variables did not reveal differential responses on MESSIER or VABS subscales based on age, race, gender, deafness, blindness, or ambulation.

It was surprising that the variable related to age did not produce differences in social and adaptive functioning. One might expect that persons who are of advanced age would have longer history of psychotropic medication use resulting in lower levels of adaptive skills. However, the current findings did not support this idea, and these results may suggest that skill deterioration is similar for individuals who have received medication for periods of time surpassing three years (Rubin, 1997; Singh et al., 1993). These new findings support past conclusions and reaffirm the need for valid diagnostic practices, conservative prescribing practices, and ongoing measures of learning and adverse side effects in persons with mental retardation who receive antipsychotic medication.

Current findings are consistent with past literature concerning medication effects on prosocial behavior and learning in persons with mental retardation. Antipsychotic medication, in both the traditional and atypical classes, has consistently suppressed behavioral repertoires (appropriate and maladaptive) in persons with mental retardation (Gedye, 1998; Dent, 1995; Diaz, 1996). However, these medications do not appear viable as first line treatments for behavior problems due to the adverse impact they have on the individual's spectrum of positive behavior. There are clearly those cases when antipsychotic medications are not only indicated but necessary in treatment regimes. First, when psychosis is clearly observed and diagnosed, antipsychotic medications are needed for appropriate and effective treatment. Additionally, antipsychotic medications may be indicated for conditions not responsive to other behavioral and pharmacologic treatments. However, these latter cases are few and far between, and prescriptions for medications in this class for problems other than true psychosis should be avoided in most cases (Matson et al., 2000).

Much of the same is true for persons receiving anti-epileptic medications (AEDs). While current results indicated that AEDs were not as behaviorally suppressing as the antipsychotic class, they clearly had a significant negative impact on prosocial behavior. While the exact mechanism causing these differences is unknown, it has been hypothesized by many that the sedating properties and GI discomfort caused by AED use is the culprit in decreased attention, engagement, learning and social behavior (Taylor, Hetrick, Touchette, Barron, & Sandman, 1991; Walters, Barrett, Feinstein, Mercurio, & Hole, 1990). There are those conditions in which medications in this class are necessary for effective treatment. Besides seizure disorders and epilepsy, manic behavior has been shown to respond positively to particular anti-epileptic medications. However, the most common psychiatric usages of these medications include impulse control problems and aggression. Ironically, research has not indicated the effectiveness of this class in either condition in persons with mental retardation. Therefore, this practice should probably be avoided except in the most extreme cases.


A number of pertinent factors are involved with the extended use of antipsychotic medication in persons with mental retardation. Persons in the population who receive these classes of medication tend to receive the medication for many years. Most subjects in this study who have received the atypical class for the last three years had a history of traditional antipsychotic use before medications were changed. Researchers have consistently demonstrated that long term use of antipsychotic medications often results in irreversible changes in the central nervous system and neurochemical functioning (Kiernan, Reeves, & Alborz, 1995). These changes often result in increased side-effects, decreased learning, and chronic over-sedation, which are conditions that can certainly affect the acquisition and performance of social and adaptive skills. Additionally, chronic use of antipsychotic medication often perpetuates a vicious cycle of continued medication use at increased doses. Once changes in central nervous system functioning occur as a result of antipsychotic medication, the individual in question invariably requires the medication to maintain a baseline level of functioning. Therefore, the probability of increased side effects, decreased learning, and over-sedation increases exponentially, resulting in lower levels of social and adaptive functioning.

The current study has implications for clinicians and researchers alike. Treatment teams should be aware of the cost and benefits associated with each class of medication in order to make responsible treatment decisions. In those cases where medication is clearly warranted, teams must use standardized assessment instruments to ensure that medications are not resulting in suppression of the total behavioral repertoire or causing the individual in question unwarranted physiological distress.


For researchers, the implications of the current study are numerous. Many questions remain about the use of psychotropic medications in persons with profound mental retardation. Most of the research that currently exists in the area is extremely methodologically flawed (Matson et al., 2000); therefore, a need exists for a number of studies concerning medication effectiveness, medication effect on prosocial behavior, medication use in conjunction with other treatment techniques, and side-effects profiles resulting from medication use in persons with profound mental retardation. It is hoped that results similar to those found in the current study will result in better treatment decisions and improved quality of life for persons with mental retardation. However, current research protocols and methods of treatment do not suggest that a trend shift to more responsible and conservative prescribing practices is likely in the near future.


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For further information: Johnny L. Matson, PhD

Louisiana State University

Department of Psychology

Audubon Hall

Baton Rouge, Louisiana 70803-5501