What has your experience been with using SSRIs to treat negative symptoms of schizophrenia?  

In light of this study:

Stroup TS, Gerhard T, Crystal S, et al. Comparative Effectiveness of Adjunctive Psychotropic Medications in Patients With Schizophrenia. JAMA Psychiatry. 2019;76(5):508–515. doi:10.1001/jamapsychiatry.2018.4489

How do you assess improvement in negative symptoms? Have you seen benefit in negative symptoms in patients who do not have comorbid depression?