Comparison of depression symptoms between primary depression and secondary-to-schizophrenia depression

Abstract

Objectives: This study exclusively aimed to clinically assess which symptom pattern discriminates primary depression from depression-secondary to-schizophrenia. Methods: A total of 98 patients with primary depression and 71 patients with secondary-to-schizophrenia depression were assessed for identifying the clinical phenomena of depression. Diagnosis of schizophrenia was confirmed by Mini International Neuropsychiatric Interview. Each participant was, however, assessed by Patient Health Questionnaire-9 as well as Calgary Depression Scale for Schizophrenia (CDSS) for possible concurrent depressive symptoms. Results: Depressed mood, loss of interest, reduced energy and pathological guilt were more common in primary depression, whereas sleep disturbance and guilty ideas of reference were more amounting towards the diagnosis of depression secondary-to-schizophrenia. Conclusions: It is clinically hard to differentiate primary from secondary-to-schizophrenia depression, especially in the absence of obvious psychotic symptoms. However, the classical symptoms of depression like subjective depressed mood, anhedonia, reduced energy and pathological guilt are more prominent in the primary depression.