The dietary pattern of patients with schizophrenia: a systematic review.

OBJECTIVE: People with schizophrenia show a high incidence of metabolic syndrome, which is associated with a high mortality from cardiovascular disease. The aetiology of the metabolic syndrome in schizophrenia is multi-factorial and may involve antipsychotic treatment, high levels of stress and unhealthy lifestyle, such as poor diet. As a poor diet can predispose to the development of metabolic abnormalities, the aims of this review are to clarify: 1) the dietary patterns of patients with schizophrenia, 2) the association of these dietary patterns with a worse metabolic profile, and 3) the possible factors influencing these dietary patterns. METHODS: A search was conducted on Pubmed, The Cochrane Library, Scopus, Embase, Ovid, Psychoinfo and ISI web of Knowledge from 1950 to the 1st of November 2011. 783 articles were found through the investigation of such databases. After title, abstract or full-text reading and applying exclusion criteria we reviewed 31 studies on dietary patterns and their effects on metabolic parameters in schizophrenia. RESULTS: Patients with schizophrenia have a poor diet, mainly characterized by a high intake of saturated fat and a low consumption of fibre and fruit. Such diet is more likely to increase the risk to develop metabolic abnormalities. Data about possible causes of poor diet in schizophrenia are still few and inconsistent. CONCLUSION: Subjects with schizophrenia show a poor diet that partly accounts for their higher incidence of metabolic abnormalities. Further studies are needed to clarify the causes of poor diet and the role of dietary intervention to improve their physical health.

Nitric oxide in patients with schizophrenia: the relationship with the severity of illness and the antipsychotic treatment.

OBJECTIVES: Past studies regarding the relationship between nitric oxide and schizophrenia have reported controversial results. Consequently, the aims of this study are i) to analyze the differences in nitric oxide concentration between patients with schizophrenia and healthy controls, ii) to investigate the influence of antipsychotic treatment on nitric oxide, iii) to correlate nitric oxide concentration with severity of illness, and iv) to investigate the relationship between nitric oxide and any personality disorder. RESEARCH DESIGN AND METHODS: We recruited 24 patients and 24 controls; the sample was divided into three groups of 8 patients, each according to the pharmacological treatment (haloperidol, olanzapine, or risperidone). The severity of illness was assessed by PANSS and personality traits were evaluated by SCID II. A blood sample was taken to assess the plasma concentration of nitrites and nitrates. RESULTS: Patients presented higher nitrate levels than controls (p < 0.05); subjects under olanzapine reported lower nitrate levels than those treated with risperidone (p < 0.05) or haloperidol (p < 0.001). Nitrate levels were correlated with PANSS total score (rho = 0.748; p < 0.001), but not with SCID II scores. CONCLUSIONS: Despite the fact that this study found a correlation between PANSS score and nitrate levels, it is unclear whether nitric oxide is related to the severity of schizophrenia, because nitrate levels are also affected by antipsychotic treatment.