The purpose of this study is to evaluate the cognitive processes of participants with
schizophrenia, participants with nervous system and mental disorders, and healthy
Participants in this study will undergo cognitive tests of attention, memory, attention.
Participants with attention deficit hyperactivity disorder (ADHD), traumatic brain injury
(TBI), bipolar disorder, and Alzheimer's disease (AD) will be compared with participants
with schizophrenia. A group of healthy adults and children will undergo cognitive tests to
further delineate the degree of impairment in schizophrenia and neurological disorder
In this study, we propose to administer cognitive tests to schizophrenic patients and to
neurologic patients who will serve as contrast groups for neuropsychological studies of
patients with schizophrenia. These include studies of Alzheimers disease to dissociate size
and organization of lexicon and ADHD to understand error patterns on CPT-type tests of
attention and vigilance. However, the majority of studies will examine schizophrenia in
relation to normal controls.
In addition, we propose to obtain test results from a local sample of normal subjects of
varying ages and educational backgrounds to further delineate degree of impairment in these
clinical groups. As well as assessing adults we wish to assess normal children. In
particular, we wish to identify in children the size of their lexicon and their degree of
semantic organization within their lexicon.
English-speaking adults between ages 21 to 65, in good health and free from significant
Children between ages 4 to 20 must not have a history of special education, using
psychotropic medication in long-term counseling or with a history of seizures, head injury
or CNS infections.
Normal controls will be recruited and screened for exclusionary morbidity by interview
(e.g., no history of contact with mental health professionals, no history of diagnosable
alcohol and/or substance abuse).
Normal controls will be recruited from building employees, local universities, from NIMH
rosters, and the general public.
Excluded are adults with histories of dementing illness, movement disorder, affective
disorders, developmental and/or acquired brain injury. Diagnoses will be made by review of
medical records, interview, examination, and in the case of psychiatric diagnoses, a
structured interview by SCID.
Advertisement will make clear that the subjects will be asked questions about family
psychiatric history and their own history or psychiatric disorder, substance abuse, and
neurological disease. Only if the subject answers these negatively will he or she
participate in this study.