Electroencephalographic delta/alpha frequency activity differentiates psychotic disorders: a study of schizophrenia, bipolar disorder and methamphetamine-induced psychotic disorder.

Electroencephalography (EEG) has been proposed as a neurophysiological biomarker to delineate psychotic disorders. It is known that increased delta and decreased alpha, which are apparent in psychosis, are indicative of inappropriate arousal state, which leads to reduced ability to attend to relevant information. On this premise, we investigated delta/alpha frequency activity, as this ratio of frequency activity may serve as an effective neurophysiological biomarker. The current study investigated differences in delta/alpha frequency activity, in schizophrenia (SCZ), bipolar I disorder with psychotic features and methamphetamine-induced psychosis. One hundred and nine participants, including individuals with SCZ (n = 28), bipolar I disorder with psychotic features (n = 28), methamphetamine-induced psychotic disorder (MPD) (n = 24) and healthy controls (CON, n = 29). Diagnosis was ascertained with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th Edition disorders and current medication was recorded. EEG was undertaken in three testing conditions: resting eyes open, resting eyes closed and during completion of a simple cognitive task (visual continuous performance task). EEG delta/alpha frequency activity was investigated across these conditions. First, delta/alpha frequency activity during resting eyes closed was higher in SCZ and MPD globally, when compared to CON, then lower for bipolar disorder (BPD) than MPD for right hemisphere. Second, delta/alpha frequency activity during resting eyes open was higher in SCZ, BPD and MPD for all electrodes, except left frontal, when compared to CON. Third, delta/alpha frequency activity during the cognitive task was higher in BPD and MPD for all electrodes, except left frontal, when compared to CON. Assessment of EEG delta/alpha frequency activity supports the delineation of underlying neurophysiological mechanisms present in psychotic disorders, which are likely related to dysfunctional thalamo-cortical connectivity. Delta/alpha frequency activity may provide a useful neurophysiological biomarker to delineate psychotic disorders.

Pathways to care and treatment delays in first and multi episode psychosis. Findings from a developing country.

BACKGROUND: In contrast to findings from the developed world where general practitioners and mental health professionals are central in first episode psychosis pathways, studies from Africa have found GPs to play a less prominent role with other help providers such as traditional healers being more important. METHODS: We compared pathways to care, treatment delays and gender differences in patients with first versus multi episode psychosis. RESULTS: Private sector GPs were first contacts in first episode patients in as many as 38% of patients and were significantly more likely to be the first contact (odds ratio = 4.5, 95% CI = 1.38-14.67) and final referring agent (odds ratio = 6.8, 95% CI = 1.56-25.12) in first episode patients. Female multi episode patients were significantly more likely to make first contact with primary care practitioners whereas male multi episode patients were more likely to first come into contact with the police (P = 0.003) and be admitted compulsorily (P = 0.009). Only 5.6% (n = 4) of patients contacted traditional healers at some point in their pathway to care. Treatment delays and DUP in first episode patients were longer and reached a median of 4.5 versus 2.5 months in multi episode patients. Treatment discontinuation of antipsychotics occurred in 82% of multi episode patients. Despite significantly longer overall treatment delays in first episode patients the distribution of treatment delays in multi episode patients followed a similar pattern to DUP in first episode patients with a subgroup having very long delays. CONCLUSIONS: Pathways to care in this treatment setting correspond more to findings from first world and newly industrialized countries. A subgroup of multi episode patients had very long periods of untreated illness. Limitations include small sample size and the retrospective nature of data collection.