Relationship between negative symptoms and neurocognitive functions in adolescent and adult patients with first-episode schizophrenia.

BACKGROUND: This study aimed to explore differences in links between negative symptoms and neurocognitive deficits in adolescent and adult patients with first-episode schizophrenia. Schizophrenia is a mental disorder often characterized by positive and negative symptoms, reduced emotional expression, excitatory status, and poor cognitive ability. The severity of negative symptoms in patients with schizophrenia was reported to be more related to poor quality of life, weak functional ability, and heavy burden from families than with the severity of positive symptoms. Previous studies suggested correlations between the severity of negative symptoms in patients with schizophrenia and neurocognitive deficits.

METHODS: This study included 92 patients (33 adolescents and 59 adults) with first-episode schizophrenia and 57 healthy people matched by age and education level. Neurocognitive functions and clinical symptoms were assessed using a standardized questionnaire.

RESULTS: Patients with first-episode schizophrenia showed neurocognitive deficits in most neuropsychological assessments compared with healthy people. With the variable of education level controlled, the negative factor score of adolescent patients with first-episode schizophrenia was strongly correlated with more time spent in part 1 (r = .646) and part 2 (r = .663) of the trail making test, and moderately correlated to more perseverative errors (r = .425) of the Wisconsin card sorting test and fewer correct trials 2 (r = -.425) of the continuous performance test. However, no such correlations were found in adult patients.

CONCLUSIONS: This study indicated significant correlations between negative symptoms and most neurocognitive functions in patients with first-episode schizophrenia, with a stronger correlation in adolescent patients.

TRIAL REGISTRATION: The trial registration number is ChiCTR-COC-14005302 , while retrospectively registered on January 5, 2014.