Prader-Willi Syndrome and Positive
An Alternative Method of Treatment
Stanley L. Swartz, Ph.D.
California State University
Prader-Willi Syndrome is a syndrome that is characterized by mental retardation,
short stature, obesity, hypogonadism, and hyperphagia (compulsive eating).
The syndrome is relatively rare, affecting approximately 1 in 15,000 people.
Various learning and behavioral difficulties make Prader-Willi difficult
to treat. Tradition methods of behavior modification have been used with
some success in school and home environments. Positive Behavior Support
(PBS) is found to hold great promise as an alternative method of treatment.
PBS shifts the focus from the typical manipulation of consequences used
in behavior modification to the analysis of environmental and behavior
deficits. These data are then used to determine the function of inappropriate
behaviors and design a positive approach to teaching appropriate behaviors.
Research on Characteristics of Prader-Willi
There has been considerable research on Prader-Willi Syndrome since it
was first described in 1956 by Prader et al. This research has focused
on genetics, major physical characteristics, hypothalamic dysfunction,
medical abnormalities, psychological and behavioral characteristics, cognition,
and learning difficulties (Waters, 1999). Research on effective treatment
methods has been less extensive though various behavioral techniques have
been found to be the most effective.
PWS can be caused by more than one genetic abnormality, but all are related
to missing genetic coding from the paternal chromosome 15.
Major Physical Characteristics
Low muscle tone is evident from birth, including poor sucking ability
which makes feeding difficult and has implications for later speech problems.
Muscle tone can be helped with appropriate exercise (Eiholzer et al.,
Evident earlier in males however both males and females experience delayed
The tendency to obesity can be life threatening and is caused by excessive
eating and low physical activity.
Typical facial characteristics
Facial features might include a narrow forehead, ‘almond shaped’
eyes with upward slanting lower eyelids, and a down turned mouth. Hair
and skin coloring is often lighter than family members.
Hyperphagia (eating more food than required)
Excessive appetite is the most well known feature of PWS. The mechanism
that informs most people that they have had enough to eat is faulty in
PWS and results in numerous behavior problems, i.e., stealing food from
others, eating pet food.
Average height without hormone treatment is 4’10” for females
and 5’2” for males. Hands and feet are both typically smaller.
Because sleeping patterns are regulated by the hypothalamus these are
usually affected in PWS. Children usually require naps and adults are
prone to daytime sleepiness.
Both delayed and arrested emotional development are typical. These include
various acting out behaviors as well as temper tantrums and stubbornness.
Other Medical Abnormalities
These medical abnormalities vary from individual to individual but are
sometimes associated with PWS.
Adverse reaction to drugs
Some adverse effects have been found from drugs that affect the central
nervous system (e.g., tranquilizers).
Prolonged drowsiness after anesthesia
Use of general anesthesia has been known to cause prolonged drowsiness.
Irregular body thermostat
The hypothalamus also controls body temperature and erratic behavior might
be noted in extreme hot or cold weather.
High pain threshold
Both hyper and hyposensitivity to pain might be present.
Careful monitoring of a child’s activity is necessary both because
of pain threshold and because of easy bruising.
Lack of vomiting
Low muscle tone can result in the inability to vomit.
Eye squinting and myopia (shortsightedness) are common. Nystagmus (involuntary
jerking of the eyeball) has also been reported.
Curvature of the spine
Scoliosis is the most common curvature in PWS.
Both eczema and cellulitis are high risks for PWS.
Immature sexual development and delayed puberty
Secondary sex characteristics are slow to develop in both sexes and menstruation
is later for girls. PWS are not sterile but have a high risk for various
Dental and oral problems
Oral problems include thick saliva. Dental problems can include poor tooth
enamel, high palate, and a small jaw.
Diabetes is associated with significant obesity.
Speech and language problems
Common in both children and adults.
Psychological and behavioral characteristics
Various researchers have tried to identify a behavioral phenotype for
PWS that might have a genetic basis (Dykens & Kasari, 1997; Curfs
et al., 1995; van Lieshout et al., 1998; Dykens & Cassidy, 1995).
Temper tantrums are frequent and can be extremely violent and unpredictable.
Stubbornness is linked to the desire to keep a routine.
Resistance to change
Need for routine is similar to that found in children with autism.
Obsessive and/or compulsive behavior
This behavior is found in as many as 80% of PWS. Obsessive behaviors intrude
on appropriate participation in activities.
Hoarding and possessiveness
Hoarding and being unwilling to share is common in PWS and is linked to
This is usually manifested as persistent talking or questioning on one
Unique to PWS, this behavior starts with children picking an existing
spot or wound and spreads to other parts of the body.
Immature social skills
Difficulties with turn taking or being part of a group are common. Most
are eccentric and have problems understanding other’s points of
Most PWS individuals are within the mild mental retardation range and
many have severe learning difficulties. Though the range of intellectual
ability varies, most do not perform at their tested level of ability.
Strengths and weaknesses
A chart of strengths and weaknesses using teacher data describe these
Relationship between intellectual ability and behavior
High I.Q. does not seem to protect PWS from behavioral manifestations
associated with the syndrome (Dykens & Cassady, 1995).
Relationship between intellectual ability and obesity
This relationship has not been established. It is theorized that those
with higher intelligence are more resourceful in seeking out food sources
(Dykens et al., 1992).
Relationship between intellectual ability and age
Ability has not been found to decrease with age but is rather a phenomenon
of an increasing ability gap between PWS and peers (Taylor, 1988).
Speech and language disorders
Speech disorders are common and occur in as many as 70% of PWS individuals.
These can be the result of oral motor abilities. Problems in pitch have
also been noted (Akefeldt et al. 1997). Expressive language has been found
to be more impaired than receptive language (Kleppe et al., 1990).
Specific learning difficulties
Difficulty with auditory processing
This problem might result in having difficulty understanding verbal instructions
or receiving too many instructions at once.
Repeated questioning on the same topic is a common behavior.
Difficulties with abstract concepts
Time concepts and temporal meanings are frequently confused.
Difficulty with problem solving strategies
Some stubbornness can be attributed to difficulty with sequential processing.
What is learned will be difficult to unlearn. This form of concrete thinking
makes it difficult to follow a line of logic or learn from experience.
Poor short-term memory
Though short term memory is a problem (what is learned one day might be
forgotten by the next) long term memory for persons, places and events
might be very good.
Difficulty with applying methods
Even directions learned by rote can be difficult to understand or apply.
A rule that applies in one situation might not be used in another similar
Treatment and Education
Treatment for individuals with PWS needs to be carefully designed with
special attention to behaviors that are associated with the syndrome.
Few medical treatments are known to be effective therefore treatment and
educational methods are primarily those that focus on behavior management
and teaching of appropriate behaviors. Particular emphasis will need to
be given to dietary needs and supervision, behavioral problems with focus
on temper tantrums and obsessive behaviors, social skills, and inclusion
in classes and activities with normal children. If successful intervention
is to be accomplished, consideration must be given to the development
of social skills and other appropriate behaviors that will contribute
to successful integration in school, community, and home environments
(Swartz, 1998). Work with individuals with PWS must include techniques
that meet a high standard of social acceptability. To accomplish this,
a system of behavior change that is as effective as typical behavior modifications
programs yet is appropriate in home and community settings, has been identified.
Positive Behavior Support
One of the major obstacles to the treatment of individuals with Prader-Willi
Syndrome, in school, community, and home settings, is behavior that is
inappropriate and disruptive. Behaviors such as tantrums, stubbornness,
various compulsive behaviors (in particular compulsive eating), are challenging
beyond what many teachers and parents are prepared to handle. Families
and those who work with individuals with Prader-Willi Syndrome are looking
for treatment methods beyond the traditional manipulation of consequences
offered by most behavior management programs.
If appropriate programs are to be designed, ones that allow a normal family
life, it will be necessary not only to identify treatment methods that
work, but ones that will be acceptable in the context of inclusive environments.
The three concepts of social validity identified by Wolf (1978) are important
considerations in reaching this goal. These are, feasibility - are we
able to use the strategy; desirability – are we willing to use the
strategy; and effectiveness – does the strategy make a difference
for the individual in increasing inclusion opportunities? In other words,
treatment strategies are needed that both parents and teachers are able
and willing to use and that make a real difference for the lifestyle of
the individual and their opportunities to participate in school, community
An increasing body of research in the use of positive behavior support
(PBS) has demonstrated that these strategies are highly effective for
use with the behaviors presented by children with severe disabilities
(Carr, Horner & Turnbull, 1999). In addition, PBS meets the various
social validity criteria in most cases and facilitates inclusion of children
with disabilities. Unlike traditional behavior management, which views
the individual as the sole problem and seeks to “fix” him
or her by quickly eliminating the challenging behavior, PBS views such
things as settings and lack of skill as parts of the “problem”
and works to change those. As such, PBS is characterized as a long-term
approach to reducing the inappropriate behavior by teaching a more appropriate
behavior, and providing the contextual supports necessary for successful
outcomes (ERIC, 1999).
Effective behavior change must not only reduce inappropriate behaviors
it must also teach suitable alternatives. These changes should not only
help the individual in the immediate environment, or the short term, they
must also be important for their life after school, or the long term.
The key concept of PBS was then determined to be to change a problem behavior,
it is first necessary to remediate deficient contexts. Deficient contexts
were found to come in two varieties, those related to behavior repertoires
and those related to environmental conditions. Behavior repertoires means
that the individual does not have the necessary behaviors to be successful.
Communication skills, social skills, self-management are all found to
be inadequate for the demands of their day-to-day existence, whether in
school, home, or community. Environmental conditions means that the stimuli
in any particular environment are not conducive to appropriate behavior
for this individual and contribute to the emergence of problem behaviors.
In applying PBS, the research review completed by Carr and his colleagues
found two categories of intervention: stimulus-based and reinforcement-based
(Carr, et al., 1999). When environments are deficient it is when there
are too few stimuli to support positive behavior and that changes in this
environment are necessary as part of the effort to help children with
disabilities exhibit more appropriate behavior. On the other hand, from
a reinforcement perspective, the existence of positive behaviors competes
with or makes negative behaviors unnecessary because the positive behaviors
provide an alternative for accessing the available reinforcement. In sum,
PBS tries to change the environment so that the conditions for appropriate
behavior and its reinforcement are available and to teach appropriate
behaviors as a substitute for accessing reinforcement in the environment.
Positive behavior support appears to be best suited for long-term change
and is proactive to the extent that it attempts to teach behaviors and
impact the environment that surrounds these behaviors. This is contrasted
to aversive or punitive approaches that seem best suited to crisis management.
From the perspective of the family, and in keeping with the principles
of social validity, PBS would seem to be the appropriate choice because
of its good fit with a family environment. Parents are able to work with
their children using techniques that are effective and at the same time
part of a normal pattern of interaction. From the perspective of the school,
PBS is a good match because of its suitability for use in inclusive settings
and because it is primarily a teaching method. Positive behavior support
is a procedure more likely to encourage the inclusion of children with
disabilities in general classrooms.
Using Positive Behavior Support with Prader-Willi Syndrome
Functional Analysis of Behavior
The use of PBS is initiated with a functional analysis of behaviors. This
process answers the question of what function(s) does the problem behavior
serve for the individual? What might the person be communicating? The
hypothesis that should be developed for each problem behavior is: 1) when
does the behavior happen? (what are the specific antecedent and setting
events that are associated with this behavior?), 2) describe the specific
problem behavior, and 3) what are the possible function(s) of this behavior?
Common functions and communicative intent of problem behaviors include:
1) to gain access to social interaction, 2) to gain access to activities,
objects, food, 3) to terminate or avoid unwanted situations, and 4) to
gain access to stimulating events (Bambara & Knoster, 1998).
Antecedent and Setting Event Modifications
A first step of intervention that can have powerful results is to consider
the environment and any events that might be antecedents to problem behaviors.
Modifications of this kind have the advantage of avoiding undesirable
behaviors by making changes before they occur. These might include: 1)
removing a problem event such as avoiding a situation known to agitate
the individual, 2) modifying a problem event such as shortening the expectation
for on-task behavior, mixing hard and easy tasks using new tasks with
mastered tasks, 3) adding events that promote desired behavior such as
providing for choice and preferences, and 4) neutralizing the impact of
negative events by allowing frequent breaks during difficult tasks.
Teaching Alternative Skills
Rather than focusing on undesirable behaviors, PBS focuses on the desired
behavior. It is assumed that the individual does not have the appropriate
behavior or does not have it in sufficient strength to use it when it
These might include: 1) replacing skills where the behavior taught is
a one-to-one substitute for the function of the undesirable behavior,
2) teaching general skills that can help the individual change a problem
situation and avoid the need for the problem behavior, and 3) teaching
coping and tolerance skills needed to help the individual deal with problems
that they encounter.
Management of Consequences
The management of consequences of behaviors is a method used to teach
an individual to use alternative behaviors. This teaching is part of the
PBS approach as contrasted to the primary focus of typical behavior management
systems that only apply consequences. These might include: 1) increasing
the use of alternative behaviors by prompting the use of the appropriate
behavior and subsequent reinforcement, 2) reducing the outcomes of inappropriate
behavior by redirecting the individual to an appropriate behavior or providing
corrective feedback, and 3) implementing a crisis management procedure
that redirects the individual to more appropriate responses and behaviors.
Behaviors that Affect Lifestyle
When we think of lifestyle we think of the routines of normal life and
the behaviors necessary to successfully participate in inclusive settings.
The overriding factor in program development is to consider how the quality
of life is improved for the individual. These might include: 1) teaching
behaviors that focus on relationships, choice and control, preferred activities,
and inclusion, and 2) focus on permanent adaptations and skills that can
be used in various settings (Bambura & Knoster, 1998).
Redirective Therapy with Prader-Willi Syndrome
Redirective Therapy was developed as part of a training program in a university
clinic for parents and families of children with severe disabilities (Swartz,
1994). Parents had reported that though some techniques currently available
appeared to be effective, they were too harsh and too unusual as a pattern
of parent-child interaction. They felt that the treatment became an aversive
to both parent and child because of its intensity and that its suitability
for the community or an inclusive school setting was also an issue. The
criteria used in the development of Redirective Therapy (RT) was that
it must allow for a positive interaction between parents and their children
and that it must be suitable for use in all settings. Using research in
nonpunitive techniques (Donnellan, et al., 1998), the strategy focused
on a simple pattern of redirection with teaching an appropriate behavior
as the end goal. Similar in this regard to the strategy identified as
differential reinforcement of alternative behavior (DRA), Redirective
Therapy diverged by electing to use only social rewards. It was felt that
since one of the primary goals for most children in the program was increased
socialization, the use of social rewards would be the first important
step in teaching social skills. Redirective Therapy is an application
of Positive Behavior Support that can be applied in inclusive settings
(school, community, and home) and used by individuals without specific
professional training, (i.e., parents and caretakers). It also begins
with a functional analysis of behaviors. Both the environment and the
behavior repertoire of the individual are considered. Environmental impacts
on problem behavior are modified or removed as a first step. Specific
behaviors that the individual needs are the focus in the next steps. Rather
than focusing on undesirable behaviors, RT focuses on teaching children
appropriate alternative behaviors that have the same function.
Parents, therapists and teachers using RT are taught to interrupt the
undesired behavior and redirect the child to an appropriate behavior.
They are instructed to do this interruption in the least intrusive way
possible (for example, a word or a gesture would be a preferable interruption
to a physical cue). Social reinforcement (praise or touch, or both) would
immediate follow the interruption and redirection. In this way, the concern
about limited availability of reinforcement in the use of differential
reinforcement of other behaviors (DRO) is resolved. This pattern is repeated
until the child stays on the new task and exhibits an appropriate behavior.
Parents report that their positive feeling about this strategy is that
they can use it at home and on any trips into the community. In another
words, it meets both the social validity criteria of feasible (I can use
it) and desirable (I will use it).
The cycle of Redirective Therapy illustrated is a pattern of interaction
that can be used by parents, therapists or teachers in any setting. It
does not rely on external or tangible reinforcement and should result
in a higher level of internalization. The particular advantage for using
RT with PWS is the coordination of teaching methods between home and school
and the normal pattern of interaction that it represents. Punishment and
negative reinforcement have no place in efforts to treat individuals with
In addition to particular emphasis on behaviors necessary to participate
in school settings such as establishing classroom routines and expectations,
and management of various inappropriate behaviors, consideration needs
to be given to the development of academic skills and achievement. With
carefully planned instruction most individuals with PWS can succeed in
both literacy and numeracy. Learning difficulties referenced earlier will
be an important part of developing individualized educational programs.
Numeracy skills are more difficulty because of deficits in abstract concepts.
Using the same concept or procedures for more than one problem is an additional
difficulty. Generally success will depend on the resourcefulness of the
teacher in making numeracy concepts concrete. Individuals can be expected
to also use spatial concepts more effectively than those that are abstract.
Teaching methods that emphasis small steps and using mathematical concepts
in real life applications are more likely to result in progress.
Literacy is generally reported as a strength in individuals with PWS.
Writing might be affected by poor muscle development and motor control,
but reading can be considered an opportunity to excel. Nevertheless, students
often learn reading skills by learning to write their own messages (Swartz,
Klein, & Shook, 2001). The reciprocity of reading and writing (what
one reads, one can also write) should be emphasized. Individuals with
PWS have been found to learn words by sight rather than by phonic analysis.
Comprehension is often a mismatch for what the individual is able to decode
and read out.
Direct instruction in reading needs to include helping individuals develop
the necessary reading behaviors to decode and understand text. These include:
1) monitoring your own behavior as you read, 2) comparing sources of information
in the text, phonics and comprehension, 3) fluency, where the reader is
encouraged to read at the usual rate of speaking, and 4) correction, the
reader recognizes errors and corrects them as they read (Swartz, Shook,
& Klein, 2003).
The following chart can be used as prompts for teachers and parents to
support reading development.
In addition, once the individual has read text, it is important to make
sure that they are reading for meaning and not just calling words from
memory. The following chart includes various questions that can be used
to probe for comprehension.
Individuals with Prader-Willi Syndrome can be successful in both social
and academic settings with appropriately designed programs of treatment
that consider the major characteristics of the syndrome. Using strengths
and teaching appropriate behaviors should be the primary focus. Training
of parents and teachers in Positive Behavior Support is a necessary part
of coordinating efforts between home and school and increasing the opportunities
for individuals with Prader-Willi Syndrome to participate in inclusive
Akefeldt, A., Akefeldt, B., & Gillberg, C. (1997). Voice, speech and
language characteristics of children with Prader-Willi syndrome. Journal
of Intellectual Disability Research 41 (4), 302-11.
Bambara, L.M. & Knoster, T. (1999). Designing positive behavior support
plans. Washington, DC: American Association on Mental Retardation.
Carr, E.G., Horner, R.H., & Turnbull, A.P. (1999). Positive behavior
support for people with developmental disabilities. Washington, DC: American
Association on Mental Retardation.
Carter, C.H. (1975). Handbook of mental retardation syndromes (3rd edition).
Springfield, IL: Charles C. Thomas.
Carter, C.H. (1978). Medical aspects of mental retardation. Springfield,
IL: Charles C. Thomas.
Curfs, L.M., et al. (1995). Personality profiles of youngsters with Prader-Willi
syndrome and youngsters attending regular schools. Journal of Intellectual
Disability Research 39 (3), 241-48.
Donnellan, A., LaVigna, G., Negri-Shoultz, N., & Fassbender, L. (1988).
Progress without punishment. New York: Teacher’s College Press.
Dykens, E.M., et al. (1992). Profiles, correlates, and trajectories in
intelligence in Prader-Willi syndrome. Journal of the American Academy
of Child and Adolescent Psychiatry 31 (6), 1125-30.
Dykens, E.M. & Cassidy, S.B. (1995). Correlates of maladaptive behavior
in children and adults with Prader-Willi syndrome. American Journal of
Medical Genetics 60, 546-9.
Dykens, E.M. & Kasari, C. (1997). Maladaptive behavior in children
with Prader-Willi, Down syndrome, and nonspecific mental retardation.
American Journal on Mental Retardation 102 (3), 228-37.
Eiholzer, U., et al. (1998). Treatment of human growth hormone with Prader-Labhart-Willi
syndrome reduces body fat and increases muscle mass and physical performance.
European Journal of Paediatrics 157, 368-77.
ERIC Research connections in special education (Winter, 1999). Positive
behavior support. ERIC Clearinghouse on Disabilities and Gifted Education.
Grossman, H.J. (1983). Classification in mental retardation. Washington,
DC: American Association on Mental Deficiency.
Kleppe, S.A., et al. (1990). The speech and language characteristics of
children with Prader-Willi syndrome. Journal of Speech and Hearing Disorders
Lucyshyn, J.M., Dunlop, G., & Albin, R.W. (2002). Families and positive
behavior support. Baltimore, MD: Paul H. Brookes.
Swartz, S.L., Shook, R.E., & Klein, A.F. (2003). Guided reading and
literacy centers. Carlsbad, CA: Dominie Press.
Swartz, S.L., Klein, A.F., & Shook, R.E. (2001). Interactive writing
and interactive editing. Carlsbad, CA: Dominie Press.
Swartz, S.L. (2000). Positive behavior support: An inclusion strategy.
Oceanside, CA: University Associates Press. http://www.stanswartz.com/positivebehaviorsupport.htm
Swartz, S.L. (1998). Inclusion of children with disabilities in regular
school programs. In Z. Jacobo & M. Villa, Sujeto, educacion especial
e integracion. Mexico: Universidad Nacional Autonoma de Mexico.
Swartz, S.L. (1998). Restructuring special education: Three generations
of school reform. Oceanside, CA: University Associates Press.
Swartz, S.L. (1994). Redirective therapy: Guidelines for use in school
and home. San Bernardino, CA: California State University.
Taylor, R.L. (1988). Cognitive and behavioral characteristics, in Caldwell,
M.L. & Taylor, R.L. (eds.) Prader-Willi syndrome - Selected research
and management issues, 29-42. New York: Springer-Verlag.
van Lieshout, C.F.M. et al., (1998). Problem behaviors and personality
of children and adolescents with Prader-Willi syndrome. Journal of Pediatric
Psychology 23 (2), 111-20.
Waters, J. (1999). Prader-Willi syndrome. London: David Fulton.
Wolf, M.M. (1978). Social validity: The case for subjective measurement,
or how applied behavior analysis is finding its heart. Journal of Applied
Behavior Analysis 11, 203-214.
Prader-Willi web sites
http://www.pwsausa.org Prader Willi
association web site (English/Spanish)
Spanish Prader Willi site
Spanish version in California
Prader Willi Society Organization (various languages)
Willi in Chile
Related web site maintained by Dr. Swartz
Other Prader-Willi web sites
Prader Willi in New York
Prader Willi in Ontario, Canada
outline of Prader Willi
basic Prader Willi info
http://www.p-war.org Research organization
Prader Willi FAQ page
Prader Willi site
Prader Willi in the UK
Prader Willi paper
Prader Willi genes and disease site
Prader Willi general practitioners site
Prader Willi in New Jersey
Arizona chapter of Prader Willi
http://www.pws.asn.au Prader Willi
Prader Willi in Argentina
Willi in New Zealand
Prader Willi in South Carolina
Prader Willi in Germany
http://www.pwsaohio.org Prader Willi
Prader Willi in Florida
Prader Willi and Angelman syndrome
Contact a Family Organization
Stanley L. Swartz, Ph.D.
Professor of Education
California State University
Visiting Professor, Facultad de Cientas Humanas,
Universidad Autonoma de Baja California
E-mail - firstname.lastname@example.org_swartz@eee.org
Web page - www.stanswartz.com