ABSTRACT
BACKGROUND: Testosterone has been implicated in suicidality in cross-sectional studies. Stress that coincides with a suicide attempt may alter androgen levels, so prospective studies are needed to exclude reverse causation. We aimed to examine the associations of plasma androgens with concurrent and future suicidality, and if present, whether these associations were mediated by a behavioral trait like reactive aggression. METHODS: Baseline plasma levels of total testosterone, 5α-dihydrotestosterone, and androstenedione were determined with liquid chromatography-tandem mass spectrometry, and dehydroepiandrosterone-sulphate with a radioimmunoassay. Suicidality was assessed using the Suicidal Ideation Scale at baseline and after 2-, 4-, 6-, and 9-year follow-up. Men and women were analyzed separately, and potential confounders were considered. RESULTS: Participants (N = 2861; 66.3% women) had a mean age of 42.0 years (range 18-65) and almost half (46.9%) fulfilled criteria for a major depressive or anxiety disorder. At baseline 13.2% of men and 11.2% of women reported current suicidal ideation. In participants who were non-suicidal at baseline, slightly more men than women reported suicidal ideation during follow-up (14.7% vs. 12.5%), whereas the reverse pattern was observed for suicide attempts (3.6% vs. 4.2%). None of the associations between androgens and current and future suicidality were significant. LIMITATIONS: Androgens were determined once, which may have been insufficient to predict suicidality over longer periods. DISCUSSION: The lack of associations between plasma levels of androgens determined by 'gold-standard' laboratory methods with suicidality do not support previous cross-sectional and smaller studies in adult men and women with values within the physiological range.
Subject(s)
Depressive Disorder, Major , Suicide , Adolescent , Adult , Aged , Androgens , Cohort Studies , Cross-Sectional Studies , Female , Humans , Longitudinal Studies , Male , Middle Aged , Plasma , Prospective Studies , Risk Factors , Suicidal Ideation , Young AdultABSTRACT
BACKGROUND: At present, the use of repetitive transcranial magnetic stimulation (rtms) for treatment-resistant depression is sufficiently substantiated to be applied in clinical practice. In the Netherlands, it will be reimbursed when offered in combination with cognitive behavior therapy.
AIM: Proposal for a clinical treatment protocol for rtms in The Netherlands.
METHOD: A study of the literature and a critical appraisal of available international guidelines for rtms.
RESULTS: rtms is a safe treatment for patients suffering from a moderate to severe depressive disorder that is relatively treatment-resistant. The duration of the effect is still unknown. It is advised to stimulate the left dorsolateral prefrontal cortex using an intensity of 120% of the resting motor threshold, with a frequency of 10 Hz and using 3000 pulses per session during a total of 20-30 sessions.
CONCLUSION: The proposed treatment protocol is favored based on the available evidence when rtms is used as a treatment aimed to acutely decrease the severity of depressive symptoms. It is further proposed to systematically collect technical and outcome data on treatment with rtms to further improve treatment with rtms in clinical practice.
Subject(s)
Depressive Disorder, Treatment-Resistant/therapy , Transcranial Magnetic Stimulation/methods , Clinical Protocols , Humans , Netherlands , Treatment OutcomeABSTRACT
Natural marine phytoplankton assemblages from Bahía Bustamante (Chubut, Argentina, 45 degrees S, 66.5 degrees W), mainly consisting of cells in the picoplankton size range (0.2-2 microm), were exposed to various UVBR (280-315 nm) and UVAR (315-400 nm) regimes in order to follow wavelength-dependent patterns of cyclobutane pyrimidine dimer (CPD) induction and repair. Simultaneously, UVR induced photosynthetic inhibition was studied in radiocarbon incorporation experiments. Biological weighting functions (BWFs) for photoinhibition and for CPD induction, the latter measured in bare calf thymus DNA, differed in the UVAR region: carbon incorporation was reduced markedly due to UVAR, whereas no measurable UVAR effect was found on CPD formation. In contrast, BWFs for inhibition of photosynthesis and CPD accumulation were fairly similar in the UVBR region, especially above 300 nm. Incubation of phytoplankton under full solar radiation caused rapid CPD accumulation over the day, giving maximum damage levels exceeding 500 CPD MB(-1) at the end of the afternoon. A clear daily pattern of CPD accumulation was found, in keeping with the DNA effective dose measured by a DNA dosimeter. In contrast, UVBR induced photosynthetic inhibition was not dose related and remained nearly constant during the day. Screening of UVBR or UVR did not cause significant CPD removal, indicating that photoreactivation either by PAR or UVAR was of minor importance in these organisms. High CPD levels were found in situ early in the morning, which remained unaffected notwithstanding treatments favoring photorepair. These results imply that a proportion of cells had been killed by UVBR exposure prior to the treatments. Our data suggest that the limited potential for photoreactivation in picophytoplankton assemblages from the southern Atlantic Ocean causes high CPD accumulation as a result of UVBR exposure.
