Altered peripheral immune profiles in treatment-resistant depression: response to ketamine and prediction of treatment outcome.

A subset of patients with depression have elevated levels of inflammatory cytokines, and some studies demonstrate interaction between inflammatory factors and treatment outcome. However, most studies focus on only a narrow subset of factors in a patient sample. In the current study, we analyzed broad immune profiles in blood from patients with treatment-resistant depression (TRD) at baseline and following treatment with the glutamate modulator ketamine. Serum was analyzed from 26 healthy control and 33 actively depressed TRD patients free of antidepressant medication, and matched for age, sex and body mass index. All subjects provided baseline blood samples, and TRD subjects had additional blood draw at 4 and 24 h following intravenous infusion of ketamine (0.5 mg kg-1). Samples underwent multiplex analysis of 41 cytokines, chemokines and growth factors using quantitative immunoassay technology. Our a priori hypothesis was that TRD patients would show elevations in canonical pro-inflammatory cytokines; analyses demonstrated significant elevation of the pro-inflammatory cytokine interleukin-6. Further exploratory analyses revealed significant regulation of four additional soluble factors in patients with TRD. Several cytokines showed transient changes in level after ketamine, but none correlated with treatment response. Low pretreatment levels of fibroblast growth factor 2 were associated with ketamine treatment response. In sum, we found that patients with TRD demonstrate a unique pattern of increased inflammatory mediators, chemokines and colony-stimulating factors, providing support for the immune hypothesis of TRD. These patterns suggest novel treatment targets for the subset of patients with TRD who evidence dysregulated immune functioning.

Ecstasy (MDMA) and high prevalence psychiatric symptomatology: somatic anxiety symptoms are associated with polydrug, not ecstasy, use.

Although previous studies have examined anxiety and depression in ecstasy (+/-3,4-methylenedioxymethamphetamine; MDMA) users, it remains unclear whether symptoms are associated specifically with ecstasy or with polydrug use in general. We compared mean symptomatology and clinically significant symptoms in 45 ecstasy polydrug, 48 cannabis polydrug and 40 legal drug users, who completed standardised self-report anxiety and depression symptom measures. We further examined whether group differences were secondary to increased somatic symptom reporting, which may reflect acute/subacute drug effects. Anxiety and depression scores were higher in polydrug than legal drug users, with no difference between ecstasy and cannabis groups. There was no difference in numbers meeting criteria for clinically significant depression or 'moderate' or 'severe' anxiety, but the polydrug group contained more individuals reporting at least 'mild' anxiety symptoms than the legal drug control. Multivariate analyses indicated that anxiety alone was sufficient to discriminate groups. Polydrug users reported more somatic anxiety symptoms than legal drug users, but endorsed equivalent numbers of non-somatic symptoms. High prevalence psychiatric symptomatology in ecstasy polydrug users may be associated with polydrug rather than ecstasy use. Higher ratings in polydrug users appear to be secondary to increased somatic symptom reporting, suggesting possible impacts of drug effects on symptom endorsement.