Recent research has fueled a debate concerning the role of nicotine in the emergence of schizophrenia. The three main hypotheses are: (a) the self-medication effect, (b) the causal relationship hypothesis, or (c) the shared diathesis hypothesis. To explore this role, the study of nicotine consumption during the initial prodromal phase of schizophrenia offers important opportunities. In the present work, 10 relevant studies are reviewed, out of 727 retrieved citations, in order to address questions regarding the prevalence of smoking in the prodromal period, the time of smoking initiation, existing patterns of tobacco use in relation with the escalation of prodromal symptoms into first psychotic episode, and potential differences in symptomatology between smokers and nonsmokers. Even though there was considerable heterogeneity among studies, relevant findings are discussed. Prevalence of nicotine use during the prodromal period was reported to be 16.6–46%. Tobacco use was found to be taken up most often before or during the prodromal period of schizophrenia. Even though a protective role of smoking has been reported by one study, other studies report an increased risk for psychosis, with hazard ratios 2.77 (95% CI: 2.34–3.43) and 2.21 (95% CI: 1.11–4.42) for female and male heavy smokers (11–20 and >20 cigarettes/day), respectively. In a different study, the risk of onset was associated with the progressive use of cannabis and tobacco prior to onset, particularly with rapid escalation to the highest levels of use. Also, nicotine use in ultra high risk (UHR) for developing psychosis subjects is associated with elevated cognitive performance, namely better processing speed, visual learning, and spatial working memory. As a conclusion, it appears that evidence accumulates supporting a possible etiologic role of smoking, in the emergence of schizophrenia along with diverse effects on patients’ symptomatology, already demonstrable at the prodromal phase. Future research employing better-defined criteria should further explore the patterns of use and effects of nicotine during the schizophrenia prodrome.

Tardive dystonia due to D2 antagonists or other agents is a potentially severe extrapyramidal side effect emerging after long-term drug treatment, prevalent but not limited to psychiatric populations. Its course is often deteriorating, and available treatments are frequently far from satisfying. It presents with sustained muscle contractions, abnormal postures, and repetitive twisting movements and leads to increased psychiatric morbidity, mortality, and decline of quality of life. Inadequate clinical skill and awareness of tardive dystonia can lead to neglect or misdiagnoses, considered as conversion symptoms or of psychogenic origin. Since the syndrome is persistent and often treatment resistant, prevention should be a mainstay of clinical care. Emerging evidence supports positive effects of atypical antipsychotics, particularly quetiapine and clozapine. Therapies such as tetrabenazine, valbenazine, deutetrabenazine, anticholinergics, baclofen, benzodiazepines, vitamin E, or non-pharmacologic interventions, namely botulinum toxin A, deep-brain stimulation, have been found to be helpful in some cases of tardive dystonia. This chapter comprehensively illustrates multiple aspects of this entity, including recent advances on etiology, pathophysiology, clinical presentation, epidemiology, pharmacogenomics, and treatment, aiming to enhance and deepen clinicians' and researchers' awareness of tardive dystonia, with the final goal of ameliorating patients' prognosis and quality of life.

Coronavirus disease 2019 , identified as the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was recognized as a public health emergency by World Health Organization, and declared a pandemic on March 11, 2020. Symptoms of respiratory tract infection along with signs of the systemic inflammatory response, represent its dominant manifestation, however, extra-respiratory symptoms including abdominal pain, diarrhea, symptoms of pericarditis, or severe myalgias have been AUTHOR CONTRIBUTIONS