Using D-cycloserine to Enhance the Benefits of Cognitive Behavioral Therapy for Schizophrenia
Condition: Schizophrenia
MeSH terms: Schizophrenia
Study type: Interventional
Phase: Phase 4

Summary: 
      This study will examine whether pretreatment with D-cycloserine before cognitive behavioral
      therapy can reduce impairments still present in people with stable cases of schizophrenia as
      well as determine which traits make schizophrenics most likely to respond to D-cycloserine
      treatment.
    

Detailed description: 
      Schizophrenia is a debilitating chronic condition that affects approximately 1 % of
      Americans, who experience symptoms such as hallucinations, delusions, and disorders of
      thought and movement. These symptoms are described as positive symptoms, because they are
      experienced in addition to what healthy individuals experience. Negative symptoms, which are
      reductions in normal functioning, and cognitive deficits, which are problems in thinking,
      also plague people with schizophrenia. The negative symptoms and cognitive deficits
      associated with schizophrenia are produced in otherwise healthy people by neurotransmitters
      inhibiting the glutamatergic N-methyl-d-aspartate NMDA receptors in the brain. This
      inhibition of NMDA receptors also causes intensification of psychotic symptoms in otherwise
      stabilized schizophrenic patients. The drug D-cycloserine partially excites NMDA receptors,
      and it has been used to help patients with anxiety disorders to overcome phobias while they
      are receiving cognitive behavioral therapy. This study will examine whether D-cycloserine can
      increase the cognitive flexibility of someone undergoing CBT and thereby enhance the
      therapy's ability to reduce a patient's belief in paranoid delusions, preoccupation with
      delusions, and related distress.

      All participants will be screened to ensure proper diagnosis of schizophrenia without other
      conditions. Those who pass will be randomly assigned to receive either D-cycloserine first or
      a placebo pill first. One week after the screening, participants in the D-cycloserine group
      will be given the drug before a 1-hour session of simulated CBT treatment. Those in the
      placebo condition will receive a placebo pill before an identical session. Two weeks after
      the screening, both groups will be called back for another session of CBT, but the pills they
      receive will be switched. Those who received D-cycloserine the first week will receive
      placebo, and those who received placebo will receive D-cycloserine. The CBT sessions will
      attempt to increase cognitive flexibility in patients by asking them to provide alternate
      explanations for common situations. At screening, at the start of visits on the first and
      second weeks, and at a follow-up visit on the third week, participants will undergo a series
      of assessments, including interviews, computerized tests, and self-report measures. Belief
      in, preoccupation with, and distress caused by delusions, as well as degree of cognitive
      flexibility, will be assessed.
    

Intervention name(s): D-cycloserine; Cognitive Behavioral Therapy
Intervention type(s): Drug; Behavioral
Intervention description(s): Single, fixed 50-mg dose of D-cycloserine administered 1 hour prior to a CBT session; One-hour talk therapy session with a trained clinician aimed at increasing cognitive flexibility by examining alternative explanations to everyday situations
Other intervention name(s): Seromycin; CBT
Intervention MeSH terms: Cycloserine
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Paranoid Schizophrenia; Paranoid Delusions; CBT; D-Cycloserine