Depressed patients with and without schizophrenia have low energy, anhedonia, low motivation. When depression is reduced with antidepressant drugs and time, these negative symptoms improved. What is critical to understand is whether the reduced capacity for volition, motivation, and energy associated with negative symptoms caused by schizophrenia are responsive to antidepressant therapy. Negative symptoms secondary to dysphoric mood are quite different from primary negative symptoms. Rating scales in common use, and providing data in the studies reviewed, do not distinguish between secondary and primary negative symptoms. I believe that we have no credible evidence that primary negative symptoms are therapeutically responsive to antidepressant therapy.

View all comments by William Carpenter

I would like to express my agreement with the comment of Dr. W. T. Carpenter about the relationship between antidepressants and negative symptoms in schizophrenia. I believe, along with the authors, that at this moment there is little evidence about this relationship. I think that if the outcome of a combined treatment of antipsychotic/antidepressant drugs versus antipsychotic drugs alone is more effective, this effect could be a result from several variables or it could be that the treatment could affect distinctive and separate symptoms that the study did not describe.

As Dr. Carpenter said, the primary negative symptoms are resistant to change, so it is difficult that they were responsive to antidepressants. Thus, the study of the relationship between antidepressant drugs and schizophrenia is an interesting field of study in schizophrenia research.

View all comments by Patricia Estani