DTA (Dopaminergic Therapy for Anhedonia) Study
Condition: Depression; Anhedonia
MeSH terms: Anhedonia; Depression; Depressive Disorder
Study type: Interventional
Phase: Phase 4

Summary: 
      The purpose of this 6-week, double-blind, placebo-controlled, crossover study is to explore
      new treatment options for people with depression who have high inflammation and anhedonia.
      Thirty-five male and female participants with depression, between the ages of 25-55 years of
      age, will be randomized to two study tracks (A and B) to receive both placebo and three doses
      of L-DOPA, given in different orders. Increases or decreases in each dose will occur
      gradually over 6 weeks of the study. Participants will complete lab tests, medical and
      psychiatric assessments, neurocognitive testing and functional MRI (fMRI) scans as part of
      the study. The total length of participation is about 2 months.
    

Detailed description: 
      Depression is a widespread disorder (lifetime prevalence >20%). Current antidepressant
      medications are effective for many patients; however, more than 30% fail to respond. Of the
      patients that do respond to treatment, some continue to suffer with primary symptoms of
      depression like an inability to experience pleasure, called anhedonia. In this regard, one
      biological pathway that may contribute to symptoms of depression and particularly anhedonia
      is inflammation.

      The purpose of this 6-week, double-blind, placebo-controlled, crossover study is to explore
      new treatment options for people with depression who have high inflammation and anhedonia.
      Despite evidence of low dopamine function in patients with depression, the ability of
      existing dopaminergic therapies, like L-DOPA, to affect brain circuits in depression has yet
      to be explored. This study will help determine the best dose of an FDA-approved medication,
      Sinemet (L-DOPA) that might be used in the future to treat sub-groups of depressed
      individuals.

      Forty male and female participants with depression, between the ages of 25-55 years of age,
      will be randomized to two study tracks (A and B) to receive both placebo and three doses of
      L-DOPA, given in different orders. Increases or decreases in each dose will occur gradually
      over 6 weeks of the study. Participants will complete lab tests, medical and psychiatric
      assessments, neurocognitive testing and functional MRI (fMRI) scans as part of the study. The
      total length of participation is about 2 months.
    

Intervention name(s): Carbidopa Levodopa; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): Patients will receive L-DOPA at doses ranging from 150 to 450 mg administered at a ratio of 1 mg carbidopa for every 4 mg L-DOPA. Starting dose is 150 mg/day with dose escalation 150 mg/day per week to a final dose of 450 mg/day; A placebo is a sugar pill that has no therapeutic effect and will be administered orally. Participants will receive 1 placebo tablet matching the Carbidopa Levodopa tablet.
Other intervention name(s): Sinemet, L-DOPA; Placebo tablet
Intervention MeSH terms: Levodopa; Carbidopa; Carbidopa, levodopa drug combination
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Depression; Anhedonia