Competence to Consent to Research among Long-Stay Inpatients with Chronic Schizophrenia

Review of Kovnick, J., Appelbaum, P., Hoge, S. & Leadbetter, R. (2003).  “Competence to Consent to Research Among Long-Stay Inpatients with Chronic Schizophrenia.”  Psychiatric Services, 54(9), 1247 – 1252.

As set forth at DSM-IV-TR §295 (p. 312) persons with schizophrenia experience a variety of cognitive impairments, including: hallucinations, bizarre delusions and thought disorders.  Hallucinations are auditory, visual or other perceptual disturbances occurring outside the range of normal experience.  Delusions are distortions in thought content or erroneous beliefs usually involving a misinterpretation of perceptions or experience; a delusion is bizarre if it clearly is implausible or incomprehensible and does not derive from ordinary life experience.  A thought disorder is disorganized thinking.  These symptoms need not be co-occurrent: only one bizarre delusion or one hallucination consisting of a voice keeping up a running commentary on the person’s behavior or thoughts (or two or more voices conversing with each other) is required during a one-month period in order to qualify one as a diagnostic candidate, other genetic, neuroanatomical or neurochemical factors notwithstanding.  Informed consent of course is a necessary prerequisite for any form of treatment or human subjects experimental research.  This leads however to a puzzle: how can a person so cognitively impaired possibly be meaningfully “informed” of the risks and benefits of treatment or participation?

The authors of this study compared competence-related abilities of in-patient schizophrenics against a control group with similar age, gender, race and SES characteristics.  The study participants were administered a test called the MacArthur Competence Assessment Tool for Clinical Research (MacCAT-CR), designed to assess competence to give informed consent.  The authors do not explain how they obtained patient consent to administer this test – a logical puzzle.  The authors found significant differences on three different measures of competence-related abililties: understanding, reasoning and appreciation.  Greater degrees of psychopathology (poorer cognitive functioning) were significantly negatively correlated with understanding and appreciation.  The authors concluded that the poor performance of the inpatient group created significant difficulties in providing informed consent, validating my initial concerns as I read this paper.