Psychosis and other symptoms of Schizophrenia (SCZ), predominantly positive symptoms, can be induced by the regular use of methamphetamine (METH), resulting in a diagnosis discourse between SCZ and METH-induced psychosis. Therefore, distinguishing both disorders based on the most prominent positive symptoms is necessary. This review aims to investigate whether the psychosis induced by METH differs from that of SCZ in terms of symptomatology, behavior, genetics, clinical features, and brain imaging analysis that have not been studied comprehensively. A comprehensive search was conducted using the PubMed. A total of 248 studies were retrieved, and through careful evaluation, 18 studies were deemed pertinent to our research objectives. The quality assessment of narrative review (SANRA) was employed to evaluate the rigor and reliability of the included studies. This review showed that psychosis induced by SCZ and METH leads to many common positive symptoms, such as thought disorders, hallucinations, and delusions.
TopIntroduction
Amphetamines (AMPH) (e.g., methamphetamine (METH) and methylamphetamine) are chemical compounds that stimulate the central nervous system (CNS) (Fitzgerald & Bronstein, 2013) and have been used to treat certain disorders, such as attention deficit hyperactivity disorder (ADHD) (Castells, Blanco‐Silvente, & Cunill, 2018), narcolepsy (Mitler, Hajdukovic, & Erman, 1993), aphasia (Walker-Batson et al., 2001), and obesity (Stăcescu, Hancu, Podar, Todea, & Tero-Vescan, 2019). However, overuse or misuse of METH can lead to psychotic or positive symptoms, as observed in patients with Schizophrenia (SCZ). Moreover, patients with SCZ frequently use addictive drugs such as METH. Literature mentions cognitive problems may negatively affect chronic METH use treatment (Guerin et al., 2019). . These cognitive difficulties can have a detrimental impact on the effectiveness of treatment. Hence, it is essential to target not only the cognitive symptoms but also the positive symptoms associated with METH use. By targeting both aspects, comprehensive treatment can be provided to individuals affected by METH addiction.
SCZ is a syndrome that is characterized by positive (e.g., hallucinations (Cho & Wu, 2013; Uludag & Zhao, 2024), delusions (Takeda et al., 2018), and thought disorders) (Fletcher & Frith, 2009), cognitive (e.g., attention, logic & reasoning, lack of metacognitive awareness, and memory problems) (Cella, Swan, Medin, Reeder, & Wykes, 2013; Kahn & Keefe, 2013), general (e.g., anxiety) (Huppert & Smith, 2014), negative symptoms (Stahl & Buckley, 2007), and social dysfunction (Goldberg & Schmidt, 2001). Therefore, it is a significant burden for countries in terms of increased health expenses (Tajima-Pozo, de Castro Oller, Lewczuk, & Montañes-Rada, 2015) due to SCZ-related morbidity (e.g., cost of treatment of SCZ (Salize et al., 2009). There are mainly environmental, epigenetic, inflammatory (Hanson & Gottesman, 2005), and genetic risk factors for SCZ occurrence, such as METH addiction (H. Li et al., 2014) or smoking (Stilo & Murray, 2019).
Positive symptoms manifest when an individual experiences a loss of touch with reality, resulting in thought disorders, delusions, and hallucinations. These symptoms significantly diminish the quality of life for patients. Psychosis refers to a condition that disrupts functioning, characterized by the presence of positive symptoms observed across various psychiatric and neurological disorders. Both patients with SCZ and individuals who frequently use METH exhibit positive symptoms. Consequently, differentiating the underlying causes of positive symptoms in these conditions poses significant challenges.
Furthermore, there is a likelihood that no treatment fully reverses METH-associated symptoms (e.g., positive symptoms) (Siefried, Acheson, Lintzeris, & Ezard, 2020), and it is unclear if psychosis due to chronic METH use is a unique psychiatric problem with various associated symptoms (Wearne & Cornish, 2018). Therefore, distinguishing between both disorders may help provide suitable treatment for METH-induced psychosis and SCZ and develop better strategies to manage the different symptoms. For instance, recent developments in genetics, microbiology, neurobiology, and brain imaging have also contributed to the literature distinguishing METH-induced psychosis from positive symptoms associated with SCZ. In addition, genetic studies also showed certain differences between SCZ and METH-induced psychosis. Moreover, the psychiatric profile of METH psychosis has varied (Voce, Calabria, Burns, Castle, & McKetin, 2019).
Our objective is to categorize studies that compare SCZ, and symptoms associated with METH-induced psychosis, with the aim of gaining insights into the distinct nature and differences between positive and cognitive symptoms, genetic predispositions, and brain imaging characteristics.