Professor Mei Qiyi: Differential diagnosis of schizophrenia and bipolar disorder
Original 2016-01-31 Mei Qiyi Medical Pulse Psychiatry
Author: Mei Qiyi, Guangji Hospital, Soochow University
The differential diagnosis of schizophrenia and bipolar disorder is a topic that has been debated for a century. There is still much controversy today, and the opinions of my respected teachers and sincere friends vary greatly. I will talk about my own learning practice experience.
The clinical manifestations of schizophrenia are
▲ Positive symptoms: hallucinations, delusions, speech disorders (e.g. frequent digressions or incoherence), behavioral disorders or catatonia.
▲ Negative symptoms: affective flattening, social withdrawal, emotional withdrawal.
▲ Mood symptoms: depression, agitation, anxiety.
▲ Cognitive symptoms: impaired learning ability, impaired memory.
All domestic and international diagnostic classification systems for mental disorders today show that all of the above symptoms can be present in bipolar disorder. Obviously, it is inappropriate to distinguish schizophrenia from bipolar disorder by the presence or absence of psychotic symptoms throughout the course of the illness.
The focus of screening schizophrenia from bipolar disorder with psychotic features is that psychotic symptoms in schizophrenia are characterized by psychotic symptoms during non-emotional episodes, and psychotic symptoms during non-emotional episodes should last for a period of time; whereas hallucinations and delusions in bipolar disorder with psychotic features only occur during depressive and manic episodes. In addition, patient history and family history can help to identify the distinction.
In the 19th century, Kraepelin distinguished schizophrenia from bipolar disorder based on the persistence or intermittency of the illness, but a diagnostic gap emerged between the two that caused psychiatrists headaches. in 1933, Kasanin proposed the diagnostic name schizoaffective psychosis, resulting in two diagnostic gaps between schizophrenia, schizoaffective psychosis, and bipolar disorder.
Before the formation of psychiatric diagnostic criteria, that is, before the 1970s, the diagnosis of mental illness was based on basic symptoms + additional symptoms, such as Schneider’s first-degree symptoms, at which time the diagnosis of schizophrenia tended to be expanded. after the 1970s, the diagnostic criteria were revised: ICD-9/10, DSM-III/IV/5, CCMD-3, etc., basically following the phenomenological concept , with diagnosis based on symptoms, severity, disease duration and exclusion criteria.
Although diagnostic criteria are available, it is difficult for physicians with different clinical experience and academic inclinations to agree on the collection of data and understanding of diagnostic criteria, so the diagnosis varies widely. Questions have therefore been raised about the current approach to phenomenological diagnosis.
Points of contention
1, Schizophrenia and monophasic depression or bipolar disorder both have multiple etiologic risk factors, and disease episodes are characterized by very similar prodromal core symptoms, including long-term functional impairment prior to the first acute episode.
2. Treatment is directed at current symptom patterns such as depression, mania, and psychosis associated with neurotransmitter dysregulation, rather than at the specific underlying disease process.
3, Are there significant phenomenological and disease taxonomic differences between schizophrenia and bipolar disorder?
4, New neurobiological findings have made the original diagnostic classification system controversial.
5, The first disease episode in both schizophrenia and mood disorders show similar morphological brain abnormalities: increased ventriculo-brain ratio (VBR) in the prefrontal and temporal lobes, decreased gray matter, and decreased volume in the hippocampus-amygdala region.
Similarities
According to the current diagnostic criteria ICD-10 and DSM-5, the two disorders share striking similarities.
(i) their lifetime prevalence is about 1% in both males and females (independent of geography and culture).
② early age of onset (between late adolescence and early adulthood).
(iii) family aggregation due to genetic factors, with a similar high risk of recurrence of the same disease in relatives (10-fold increase in children).
(iv) Similar homozygous and heterozygous co-morbidity rates, both with a heritability of 60% to 80%.
In addition, both disorders are complex polygenic diseases in which multiple genes act together and are influenced by environmental factors.
Although similar but not equivalent, schizophrenia and bipolar disorder still differ greatly in many aspects of treatment and prognosis, and diagnostic classification systems such as the DSM-5 are still being improved. Until major breakthroughs in etiology and biology are made, phenomenological diagnostic criteria remain the most viable approach at this time. The debate will continue until a major breakthrough occurs.