According to the original contribution of David (1990) insight into psychosis is composed of three distinct, overlapping dimensions, namely:
- recognition that one has a mental illness,
- ability to relabel unusual mental events (delusions and hallucinations) as pathological,
- compliance with treatment
Lack of insight is widespread among patients affected by schizophrenia. In a comprehensive meta-analysis, Lincoln et al. (2007) found that between 50% and 80% of individuals suffered from partial or complete lack of insight.
Lack of insight correlates with poor adherence to medication, high rates of relapse and poor clinical outcomes (Mohamed et al, 2009), leading to poor quality of life (QoL) and worsening of social and interpersonal relationships (Joseph et al., 2015).
Even though the available antipsychotics can offer some improvement of insight in patients with first episode schizophrenia (Pijnenborg et al, 2015) and, contrary to previous pessimistic belief, lack of insight seems to be amenable to treatment, it remains a challenge along the entire course of illness (Phahladira et al., 2018).
More recent research has shown that while the path from better insight to awareness of impaired illness and acceptance of treatment is straightforward, starting from that point the clinical course begins to become more complicated. Achieving good insight by control of the positive symptoms of schizophrenia is a double-edge sword, since good insight is associated with depression, poorer self-reported quality of life and suicide (reviewed in Lysaker et al, 2018)
Along with existing and emerging psychological treatments that can favourably affect insight, a promising pharmacological approach is the use of antipsychotics that are able to improve cognition either by their intrinsic pharmacodynamic activities or by optimal modulation of dopaminergic function.
In fact, cognition can positively affect awareness of impaired illness (Ozzoude et al, 2019) and simultaneously improve those neurocognitive deficits which are central to the abnormalities that occur in schizophrenia (Kasper and Resinger, 2003) including misconstructions caused by symptoms of schizophrenia spectrum disorders occurring in the presence of apparent good insight.
- David AS. Insight and psychosis. Br J Psychiatry. 1990, 156, 798–808
- Joseph B, Narayanaswamy JC, Venkatasubramanian G. Insight in schizophrenia: relationship to positive, negative and neurocognitive dimensions. Indian J Psychol Med 2015;37:5–11
- Kasper S, Resinger E. Cognitive effects and antipsychotic treatment. Psychoneuroendocrinology. 2003, 28, Suppl 1:27-38
- Lincoln TM, Lüllmann E, Rief W. Correlates and long-term consequences of poor insight in patients with schizophrenia. A systematic review. Schizophr Bull. 2007, 33, 1324-42
- Lysaker PH, Pattison ML, Leonhardt BL, Phelps S, Vohs JL. Insight in schizophrenia spectrum disorders: relationship with behavior, mood and perceived quality of life, underlying causes and emerging treatments. World Psychiatry. 2018, 17, 12-23
- Mohamed, S., Rosenheck, R., McEvoy, J., Swartz, M., Stroup, S., Lieberman, J.A., 2009. Cross-sectional and longitudinal relationships between insight and attitudes toward medication and clinical outcomes in chronic schizophrenia. Schizophr. Bull. 35, 336–346
- Ozzoude M, Nakajima S, Plitman E, Chung JK, Kim J, Iwata Y, Caravaggio F, Takeuchi H, Uchida H, Graff-Guerrero A, Gerretsen P. The effects of illness severity, cognition, and estimated antipsychotic dopamine receptor occupancy on insight into the illness in schizophrenia: An analysis of clinical antipsychotic trials of intervention effectiveness (CATIE) data. Prog Neuropsychopharmacol Biol Psychiatry. 2019, 89:207-213
- Pijnenborg GH, Timmerman ME, Derks EM, Fleischhacker WW, Kahn RS, Aleman A. Differential effects of antipsychotic drugs on insight in first episode schizophrenia: Data from the European First-Episode Schizophrenia Trial (EUFEST). Eur Neuropsychopharmacol. 2015, 25, 808-16
- Phahladira L, Asmal L, Kilian S, Chiliza B, Scheffler F, Luckhoff HK, du Plessis S, Emsley R. Changes in insight over the first 24 months of treatment in schizophrenia spectrum disorders. Schizophr Res. 2018 Oct 29 doi: 10.1016/j.schres.2018.10.013. [Epub ahead of print]