Basic symptoms of schizophrenia
Basic symptoms of schizophrenia are subjective symptoms, described as experienced from a person's perspective, which show evidence of underlying psychopathology. Basic symptoms have generally been applied to the assessment of people who may be at risk to develop psychosis. Though basic symptoms are often disturbing for the person, problems generally do not become evident to others until the person is no longer able to cope with their basic symptoms. In the prodrome to psychosis, uncharacteristic basic symptoms develop first, followed by more characteristic basic symptoms and brief and self-limited psychotic-like symptoms, and finally the onset of psychosis.[1] In 2015, the European Psychiatric Association issued guidance recommending the use of a subscale of basic symptoms, called the Cognitive Disturbances scale (COGDIS), in the assessment of psychosis risk in help-seeking psychiatric patients; in a meta-analysis, COGDIS was shown to be as predictive of transition to psychosis as the Ultra High Risk (UHR) criteria up to 2 years after assessment, and significantly more predictive thereafter.[2] The basic symptoms measured by COGDIS, as well as those measured by another subscale, the Cognitive-Perceptive basic symptoms scale (COPER), are predictive of transition to schizophrenia.[3]
Course
Basic symptoms often appear several years before the onset of psychosis, but are often preceded by the onset of self-disorders (see supplementary material at [3]). They may sometimes appear and then disappear before appearing again much later, where they occur as part of an outpost syndrome. At one point, uncharacteristic basic symptoms will appear, which comprise various disturbances of mood, emotions, drive, thought, and attention that can occur in many other disorders, followed by the characteristic basic symptoms, which comprise disturbances of thought, perception, and attention, along with minor reality distortion, that are associated with schizophrenia in particular. Afterward, attenuated symptoms of psychosis or brief periods of psychosis will appear, before culminating in the emergence of full-blown psychosis. At any stage before psychosis, the person will attempt to cope with the basic symptoms, which might conceal the problems from others; once the person reaches the limit of their ability to compensate, however, the problems will become evident to others and cause impairment.[3]
After the resolution of psychosis, basic symptoms may follow one of 3 courses: Psychosis and the basic symptoms may resolve completely allowing the restoration of normal functioning; they may remit but remain at an uncharacteristic level, with relapses of psychosis; or the characteristic basic symptoms may remain creating a deficit syndrome dominated by negative symptoms.[3]
Evaluation
Basic symptoms are generally evaluated using the Schizophrenia Proneness Instrument (SPI), of which there are both a child and youth version (SPI-CY) and an adult version (SPI-A) (see supplemental material at [3]); this instrument assesses basic symptoms, both those that are uncharacteristic and those characteristic of psychosis. Out of the items evaluated on the SPI-CY and the SPI-A, there can be derived 2 scales to evaluate specifically the characteristic basic symptoms: the Cognitive Disturbances scale (COGDIS) and the Cognitive-Perceptual Basic Symptoms scale (COPER).[3]
COGDIS criteria are met when at least 2 of the symptoms on the scale (see table below) are present with at least weekly occurrence in the last 3 months, and which were not present during the pre-morbid phase of the illness and do not result from drug use. The European Psychiatric Association recommends the use of this scale, along with attenuated psychotic symptoms and brief transient psychosis, to detect at-risk mental states in help-seeking people.[2]
COPER criteria are met when at least 1 of the symptoms on the scale (see table below) is present with at least weekly occurrence in the last 3 months, and the first occurrence of symptoms was more than 12 months prior to evaluation.[3]
Below are the basic symptoms associated with psychosis, along with whether they appear on COGDIS, COPER, or both:[1][2][3]
| Symptom | COGDIS | COPER | Description |
|---|---|---|---|
| Thought interference | Yes | Yes | Interference of unimportant, irrelevant thoughts that hinders thinking and concentration. |
| Thought perseveration | No | Yes | Repetition of thoughts that have little or no salience. |
| Thought pressure | Yes | Yes | Many thoughts with no common theme pop up uncontrollably. |
| Thought blockages | Yes | Yes | Sudden loss of train of thought that may be accompanied by the intrusion of a new thought. |
| Disturbance of receptive language | Yes | Yes | Lack of immediate comprehension of speech or text in one's native language. |
| Disturbance of expressive language | Yes | No | Difficulty producing speech or text that is appropriate to one's message in one's native language. |
| Disturbances of abstract thinking | Yes | No | Difficulty comprehending idioms and metaphors. |
| Inability to divide attention | Yes | No | Difficulty doing something with one sense (such as vision) while simultaneously using another sense for something else (such as hearing). |
| Captivation of attention by details of the visual field | Yes | No | Attention is drawn to unimportant details as if one were "spellbound". |
| Decreased ability to discriminate between perception and ideas, true memories and fantasies | No | Yes | Difficulty discriminating between what one has observed and what one has imagined. |
| Unstable ideas of reference with insight | Yes | Yes | Sub-psychotic referential ideation that is thereafter immediately corrected by the person. |
| Derealization | No | Yes | Sense of disconnect or unreality in one's environment. |
| Visual or acoustic perceptual disturbances with insight | No | Yes | Disturbances of the perception of brightness or loudness, color or sound quality, or distortions in one's perceptions that are recognized by the person as false. |
See also
References
- 1 2 Frauke Schultze-Lutter (January 2009). "Subjective symptoms of schizophrenia in research and the clinic: the basic symptom concept". Schizophrenia Bulletin. 35 (1): 5–8. doi:10.1093/schbul/sbn139. ISSN 0586-7614. PMC 2643966
. PMID 19074497. - 1 2 3 Schultze-Lutter, F.; Michel, C.; Schmidt, S.J.; Schimmelmann, B.G.; Maric, N.P.; Salokangas, R.K.R.; Riecher-Rössler, A.; van der Gaag, M.; Nordentoft, M.; Raballo, A.; Meneghelli, A.; Marshall, M.; Morrison, A.; Ruhrmann, S.; Klosterkötter, J. (2015). "EPA guidance on the early detection of clinical high risk states of psychoses". European Psychiatry. 30 (3): 405–416. doi:10.1016/j.eurpsy.2015.01.010. ISSN 0924-9338. PMID 25735810.
- 1 2 3 4 5 6 7 8 Schultze-Lutter, Frauke; Debbané, Martin; Theodoridou, Anastasia; Wood, Stephen J.; Raballo, Andrea; Michel, Chantal; Schmidt, Stefanie J.; Kindler, Jochen; Ruhrmann, Stephan; Uhlhaas, Peter J. (2016). "Revisiting the Basic Symptom Concept: Toward Translating Risk Symptoms for Psychosis into Neurobiological Targets". Frontiers in Psychiatry. 7. doi:10.3389/fpsyt.2016.00009. ISSN 1664-0640. PMC 4729935. PMID 26858660.
