Depression as an imprecise and heterogeneous mental disorder: Consequences for clinical practice

Los trastornos depresivos constituyen un grupo enormemente heterogéneo de cuadros clínicos, cuya severidad se distribuye en un continuum que abarca, desde cuadros de dudosa o inconsistente significación clínica y próximos a las reacciones emocionales no patológicas, hasta cuadros severos con gran afectación funcional y riesgo vital. El episodio depresivo y la depresión mayor son categorías heterogéneas e imprecisas y el término depresión, aunque ampliamente utilizado en medios profesionales y extra profesionales, es todavía más ambiguo. Se subrayan algunas características clínicas que diferencian los trastornos depresivos con significación clínica del resto. Frente a la heterogeneidad clínica de los trastornos depresivos existe una llamativa uniformidad en el abordaje terapéutico, basado en la administración indiscriminada de fármacos antidepresivos para cualquier cuadro del amplio espectro de trastornos depresivos. Sería necesario desarrollar protocolos de actuación, con abordajes específicos, biológicos, psicoterapéuticos y psicosociales en función de los datos de eficacia de cada tipo de abordaje y de cada paciente específico, restringiendo los tratamientos farmacológicos a los cuadros en que han mostrado eficaciaDepressive disorders constitute a very heterogeneous group of clinical syndromes which includes from depressive syndromes of doubtful clinical significance to very severe and disabled disorders of high risk for life. The depressive episode and major depression categories, according to diagnostic criteria, are also very heterogeneous and vague entities. The “depression” term, widely used in scientific literature, is excessively ambiguous. In spite of this clinical heterogeneity, there is a striking uniformity in therapeutic management of depressive syndromes, based excessively in antidepressant drugs. Development of practice guidelines including not only biological but psychotherapeutic and psychosocial techniques is needed. Pharmacologic treatments should be restricted to more severe depressive episode

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level