Questions and Answers
Question # 48
Are persons with NLD more prone to the development of Schizophrenia than are
members of the general population?
Answer (in collaboration with Dr. Saadia Ahmad and Dr. Brian Burke):
There appears to be a slightly higher than expected incidence of the diagnosis
of Schizophrenia in persons with NLD. There are many facets, nuances, and
clarifications that need to be made vis-à-vis this generalization. Some of
these are as follows:
(1) Comorbidity. It is possible to have measles and a broken leg. It is
possible for a person to have NLD and Schizophrenia, with no shared etiological
(2) Age of onset. Schizophrenia typically appears in late adolescence.
Indications of significant psychosocial disturbance in persons with NLD are
usually evident in middle to late childhood.
(3) Rapidity of onset. The onset of Schizophrenia is typically rather
sudden, with few if any “warning signs.” Persons with NLD appear to “grow
into” their serious psychosocial difficulties.
(4) Response to antipsychotic medications. The symptoms of schizophrenia
typically recede, even disappear, with properly titrated antipsychotic medications.
Such medications have no positive effects on the psychosocial disturbances of
persons with NLD.
(5) Response to cognitive-behavioural interventions. Persons with NLD
typically respond in a very positive manner to systematic cognitive-behavioural
interventions designed to enhance skill-learning. Persons with Schizophrenia
show little or no positive response to such interventions until they receive
appropriate levels of antipsychotic medications.
(6) Paleological reasoning. This is a frequent symptom evident in persons
with Schizophrenia. The concept-formation and reasoning of persons with NLD,
although quite deficient, is free of this feature.
(7) Primary deficits of NLD. Persons with NLD exhibit their primary
deficits in tactile and visual-spatial perception, in psychomotor coordination,
and in their nonadaptive responses to novelty (see
NLD Content and Dynamics). There is no reliable evidence that these deficits
are prominent in persons with Schizophrenia.
(8) Schizo-Affective Disorder, etc. and Diagnostic Overshadowing. Over
many years of clinical practice, my colleagues and I have assessed many persons
who carry a diagnosis or Schizo-Affective Disorder, Schizophrenia NOS, atypical
Schizophrenia, and/or Schizophrenia (Disorganized Type), and who exhibited the
syndrome of NLD. Indeed, a perusal of the developmental histories of these
individuals most often revealed a course that is typical of persons with NLD,
not Schizophrenia. We have found that a treatment programme designed for
persons with NLD is a better option for them than that usually offered in a
typical psychosis pathway.
For those persons who exhibit the syndrome of NLD and some variety of
Schizophrenia, it is important to insure that both disorders receive sufficient
attention. At most significant risk for inadequate/incomplete treatment are
those whose NLD is effectively “masked” by this comorbid condition. [This is
an example of “diagnostic overshadowing.”] Of course, there is a significant
probability that what is diagnosed as Schizophrenia is much more adequately
designated as NLD. This is virtually always the case when the person is
described by experienced clinicians as exhibiting “schizoid” behaviours.
(9) Neurological Disease and the Syndrome of NLD. The too-facile diagnosis
of Schizophrenia in persons with those types of neurological disease, disorder,
and dysfunction whose behavioural phenotypes include the syndrome of NLD
(see NLD and Neurological Disease) is
fraught with problems. In such instances, for example, the administration of
psychoactive medications usually helpful for persons with Schizophrenia may be
counterproductive. In addition, the “masking” of NLD by the combination of
neurological and “schizoid” features/symptoms may divert care-givers from considering
forms of treatment emphasizing skill-learning that are crucial for persons with
Bottom Line. Persons with NLD are clearly at significant risk for being
diagnosed with Schizophrenia. Whether persons with NLD are more likely to suffer
from Schizophrenia than are members of the general population is in doubt. That
said, it is clear that persons with NLD require treatment specifically designed
for persons with NLD, regardless of any other valid or improperly diagnosed