Empirical evidence for definitions of episode, remission, recovery, relapse and recurrence in depression: a systematic review.

AIMS.: For the past quarter of a century, Frank et al.'s (1991) consensus-based definitions of major depressive disorder (MDD) episode, remission, recovery, relapse and recurrence have been the paramount driving forces for consistency in MDD research as well as in clinical practice. This study aims to review the evidence for the empirical validation of Frank et al.'s proposed concept definitions and to discuss evidence-based modifications. METHODS.: A literature search of Web of Science and PubMed from 1/1/1991 to 08/30/2017 identified all publications which referenced Frank et al.'s request for definition validation. Publications with data relevant for validation were included and checked for referencing other studies providing such data. RESULTS.: A total of 56 studies involving 39 315 subjects were included, mainly presenting data to validate the severity and duration thresholds for defining remission and recovery. Most studies indicated that the severity threshold for defining remission should decrease. Additionally, specific duration thresholds to separate remission from recovery did not add any predictive value to the notion that increased remission duration alleviates the risk of reoccurrence of depressive symptoms. Only limited data were available to validate the severity and duration criteria for defining a depressive episode. CONCLUSIONS.: Remission can best be defined as a less symptomatic state than previously assumed (Hamilton Rating Scale for Depression, 17-item version (HAMD-17) ⩽4 instead of ⩽7), without applying a duration criterion. Duration thresholds to separate remission from recovery are not meaningful. The minimal duration of depressive symptoms to define a depressive episode should be longer than 2 weeks, although further studies are required to recommend an exact duration threshold. These results are relevant for researchers and clinicians aiming to use evidence-based depression outcomes.

Will you still need me, will you still feed me when I'm 64? The health impact of caregiving to one's spouse.

Informal care may substitute for formal long-term care that is often publicly funded or subsidized. The costs of informal caregiving are borne by the caregiver and may consist of worse health outcomes and, if the caregiver has not retired, worse labor market outcomes. We estimate the impact of providing informal care to one's partner on the caregiver's health using data from the Survey of Health, Ageing, and Retirement in Europe. We use statistical matching to deal with selection bias and endogeneity. We find that in the short run caregiving has a substantial effect on the health of caregivers and, for female caregivers, on their health care use. These effects should be taken into account when comparing the costs and benefits of formal and informal care provision. The health effects may, however, be short-lived, as we do not find any evidence that they persist after 4 or 7 years.

The supercoiling state of DNA determines the handedness of both H3 and CENP-A nucleosomes.

Nucleosomes form the unit structure of the genome in eukaryotes, thereby constituting a fundamental tenet of chromatin biology. In canonical nucleosomes, DNA wraps around the histone octamer in a left-handed toroidal ramp. Here, in single-molecule magnetic tweezers studies of chaperone-assisted nucleosome assembly, we show that the handedness of the DNA wrapping around the nucleosome core is intrinsically ambidextrous, and depends on the pre-assembly supercoiling state of the DNA, i.e., it is not uniquely determined by the octameric histone core. Nucleosomes assembled onto negatively supercoiled DNA are found to exhibit a left-handed conformation, whereas assembly onto positively supercoiled DNA results in right-handed nucleosomes. This intrinsic flexibility to adopt both chiralities is observed both for canonical H3 nucleosomes, and for centromere-specific variant CENP-A nucleosomes. These data support recent advances suggesting an intrinsic adaptability of the nucleosome, and provide insights into how nucleosomes might rapidly re-assemble after cellular processes that generate positive supercoiling in vivo.