Light perception and signalling by phytochrome A

In etiolated seedlings, phytochrome A (phyA) mediates very-low-fluence responses (VLFRs), which initiate de-etiolation at the interphase between the soil and above-ground environments, and high-irradiance responses (HIR), which complete de-etiolation under dense canopies and require more sustained activation with far-red light. Light-activated phyA is transported to the nucleus by FAR-RED ELONGATED HYPOCOTYL1 (FHY1). The nuclear pool of active phyA increases under prolonged far-red light of relatively high fluence rates. This condition maximizes the rate of FHY1-phyA complex assembly and disassembly, allowing FHY1 to return to the cytoplasm to translocate further phyA to the nucleus, to replace phyA degraded in the proteasome. The core signalling pathways downstream of nuclear phyA involve the negative regulation of CONSTITUTIVE PHOTOMORPHOGENIC 1, which targets for degradation transcription factors required for photomorphogenesis, and PHYTOCHROME-INTERACTING FACTORs, which are transcription factors that repress photomorphogenesis. Under sustained far-red light activation, released FHY1 can also be recruited with active phyA to target gene promoters as a transcriptional activator, and nuclear phyA signalling activates a positive regulatory loop involving BELL-LIKE HOMEODOMAIN 1 that reinforces the HIR.

The epidemiology of perimenstrual psychological symptoms

OBJECTIVE

The purpose of this paper is to examine the prevalence, clinical significance and comorbidity of perimenstrual symptoms/syndrome (PERI-MS) in a community sample of women.

METHOD

Premenstrual and menstrual physical and psychological symptoms were assessed in a prospective longitudinal study of a representative community cohort of women (N=299) who were interviewed five times between the ages of 21 and 35 years.

RESULTS

When classified according to the severity of distress, the prevalence rates were 8.1% for severe and 13.6% for moderate PERI-MS, respectively. Clinical indicators of severity were all greater among PERI-MS women with than without depressed mood.

CONCLUSION

The results of this study suggest that irritability, nervousness and tension irrespective of the presence of concomitant depressed mood are core elements of the perimenstrual syndrome.

Historical perspectives and natural history of bipolar disorder

A review of two centuries' literature on the natural history of bipolar disorder, including modern naturalistic studies and new data from a lifelong follow-up study of 220 bipolar patients, reaches the following conclusions: the findings of modern follow-up studies are closely compatible with those of studies conducted before the introduction of modern antidepressant and mood-stabilizing treatments. Bipolar disorder has always been highly recurrent and considered to have a poor prognosis. Bipolar patients who have been hospitalized spend about 20% of their lifetime from the onset of their disorder in episodes. Fifty percent of bipolar episodes last between 2 and 7 months (median 3 months). The intervals between the first few episodes tend to shorten; later the episodes return at an irregular rhythm of about 0.4 episodes per year with high interindividual variability. Switches from mania into mild depression and from depression into hypomania were frequently reported in the 19th century and the first half of the 20th. Antidepressant and antimanic drugs have to be given as long as the natural episode lasts. Given the poor outcome of bipolar disorders found in naturalistic follow-up studies and our lifelong investigation, intensive antidepressant, antimanic, and mood-stabilizing treatments are required in most cases. Despite modern treatments the outcome into old age is still poor, full recovery without further episodes rare, recurrence of episodes with incomplete remission the rule, and the development of chronicity and suicide still frequent.

Depressive spectrum diagnoses

There has been widespread debate about the validity of the contemporary diagnostic classification system of depression. The major goal of this study is to examine the prognostic significance of each of the major subtypes of depression using data from 5 interviews of a 15-year prospective community-based cohort study. The stability of the following diagnostic subtypes across the duration of the study was examined: major depressive disorder (MDD), dysthymia, recurrent brief depression (RBD), and minor depression. The results show that there was little stability for the specific subtypes of depression among those who continued to manifest depression during the follow-up period; 51% of those with MDD and 44% of those with RBD met criteria for another subtype of depression. When stability was observed, the same subtype often occurred in combination with the development of another subtype. Among individuals with a single subtype, severity was greatest among those with dysthymia, whereas individuals with combined subtypes had greater severity than those with a single subtype. The lack of longitudinal stability of the diagnostic subtypes of depression suggests that depression is better expressed as a spectrum rather than a set of discrete subtypes.

Long-term outcome and mortality of treated versus untreated bipolar and depressed patients: A preliminary report

The mortality of patients with mood disorders is elevated as a consequence not only of suicides and accidents but also of cardiovascular and other diseases - for instance, hypothyroidism and hyperthyroidism. Long-term medication can reduce suicides by two-thirds and can probably reduce non-suicidal mortality also. This long-term study of 406 hospital admissions recruited between 1959 and 1963 and followed up until 1991 suggests that not only lithium (as reported in the literature), but also neuroleptics and antidepressants may have such beneficial effects.