Department of Mental Health, Faculty of Medicine, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria.
Department of Psychological Medicine, University of Nigeria, Nsukka, Enugu Campus, Enugu State, Nigeria.
Niger J Clin Pract. 2023 May;26(5):538-544. doi: 10.4103/njcp.njcp_435_20.
Schizophrenia, from its early conceptualization, has been described in distinct clinical subtypes. However, these categories were found not to be stable phenotypes over time, hence the dimensional option, whereas at cross-sectional level, the dimensions of psychopathology have been replicated across studies; there is dearth of data on the longitudinal stability of the factor structure of the symptoms of schizophrenia in African populations.
This study examined the longitudinal stability of the factor structure of the 18-item Brief Psychiatric Rating Scale (BPRS) across intervals of 16-week naturalistic treatment follow-up.
Consecutive incident cases that fulfilled the criteria for schizophrenia were recruited into the study. After a baseline assessment, 160 incident cases of schizophrenia were followed up 4 weekly for indicators of symptomatic outcome for 16 weeks. The Brief Psychiatric Rating Scale (BPRS) assessments were conducted in clinical interviews and with the Scale for Assessment of Negative Symptoms (SANS). Five BPRS assessments were made across the monthly intervals of follow-up. Exploratory factor analyses (EFA) using maximum likelihood extraction and varimax rotation with Kaiser normalization was used to extract the factors.
A four-factor structure was found at baseline, namely negative, positive, depressive/anxiety, and manic symptom dimensions. From week 4, the manic and anxiety/depression dimensions remained invariant over time, while negative and positive symptoms merged into a psychosis dimension that was invariant.
The persistence of the mood dimensions supports the DSM-5 recommendation to include these dimensions in the assessment of schizophrenia psychopathology. The longitudinal emergence and invariance of the psychosis factor echo the idea of unitary psychosis and, along with the prominence of mood dimensions over time, reflect recent molecular genetic findings about the sharing of genes by schizophrenia and mood disorders.
从早期的概念化开始，精神分裂症就被描述为具有明显的临床亚型。然而，随着时间的推移，这些类别被发现并不是稳定的表型，因此出现了维度选择，而在横断面上，精神病理学的维度在研究中得到了复制；关于精神分裂症症状的因子结构在非洲人群中的纵向稳定性数据匮乏。
本研究考察了 18 项简明精神病评定量表（BPRS）的因子结构在 16 周自然随访治疗间隔内的纵向稳定性。
连续符合精神分裂症标准的首发病例被纳入研究。在基线评估后，160 例首发精神分裂症患者每周进行 4 次随访，以评估 16 周的症状结局指标。BPRS 评估在临床访谈中进行，并使用阴性症状评定量表（SANS）。在随访的每月间隔进行 5 次 BPRS 评估。使用最大似然提取和 Kaiser 标准化的方差极大旋转进行探索性因子分析（EFA）以提取因子。
在基线时发现了一个四因子结构，即阴性、阳性、抑郁/焦虑和躁狂症状维度。从第 4 周开始，躁狂和焦虑/抑郁维度在整个随访期间保持不变，而阴性和阳性症状融合成一个不变的精神病维度。
情绪维度的持续存在支持 DSM-5 将这些维度纳入精神分裂症精神病理学评估的建议。精神病因子的纵向出现和不变性反映了单一精神病的观点，并且随着时间的推移，情绪维度的突出性反映了关于精神分裂症和情绪障碍共享基因的最近分子遗传学发现。
