Age at onset of non-affective psychosis in relation to cannabis use, other drug use and gender.

BACKGROUND: Cannabis use is associated with an earlier age at onset of psychotic illness. The aim of the present study was to examine whether this association is confounded by gender or other substance use in a large cohort of patients with a non-affective psychotic disorder. METHOD: In 785 patients with a non-affective psychotic disorder, regression analysis was used to investigate the independent effects of gender, cannabis use and other drug use on age at onset of first psychosis. RESULTS: Age at onset was 1.8 years earlier in cannabis users compared to non-users, controlling for gender and other possible confounders. Use of other drugs did not have an additional effect on age at onset when cannabis use was taken into account. In 63.5% of cannabis-using patients, age at most intense cannabis use preceded the age at onset of first psychosis. In males, the mean age at onset was 1.3 years lower than in females, controlling for cannabis use and other confounders. CONCLUSIONS: Cannabis use and gender are independently associated with an earlier onset of psychotic illness. Our findings also suggest that cannabis use may precipitate psychosis. More research is needed to clarify the neurobiological factors that make people vulnerable to this precipitating effect of cannabis.

Cardiovascular variability during treatment with haloperidol, olanzapine or risperidone in recent-onset schizophrenia.

This study aimed to investigate the effects of treatment with haloperidol, olanzapine and risperidone on cardiovascular variability in patients with recent-onset schizophrenia by means of spectral analysis. Unmedicated patients (n = 18) had a higher mean heart rate and a tendency for a lower high-frequency power of heart rate variability than healthy control subjects (n = 57), indicating a decreased cardiac vagal control in unmedicated patients with schizophrenia. Patients treated with haloperidol (n = 10) showed significantly lower low-frequency power of heart rate and systolic blood pressure variability compared with olanzapine-treated patients, suggesting that haloperidol attenuated sympathetic functioning. On the contrary, olanzapine-treated patients (n = 10) showed the highest power in the low-frequency range of heart rate and systolic blood pressure variability, suggesting an increased sympathetic cardiac functioning. No significant effects of risperidone (n = 13) were found. None of the antipsychotic agents differed in their parasympathetic cardiovascular effects. We conclude that young, unmedicated patients with schizophrenia differed from controls in their parasympathetic functioning, but the antipsychotic agents haloperidol, risperidone and olanzapine induced only minor cardiovascular side effects.