Adjuvant Treatment With a Glycine Uptake Inhibitor in Participants With Negative Symptoms of Schizophrenia (P05695) (MK-8435-001)

The primary features of schizophrenia are characterized by positive (irrational thoughts and/or behavior) and negative symptoms. Negative symptoms are the gross absence of normal behavior and emotions, and usually include a general lack of engagement, social withdrawal, and loss of goal-directed behavior. Negative symptoms may strongly affect daytime activities and quality of life. The effects of currently available antipsychotics on negative symptoms are not satisfactory and leave much room for improvement. MK-8435 (Org 25935) is an investigational drug that may help to correct the above characteristics of schizophrenia by facilitating the messenger function of an amino acid in the brain, called glutamate. Preliminary data suggest that lowered glutamate levels in schizophrenia are associated with a failure to activate relevant areas in the forebrain and with prominent negative symptoms.