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PubMed1995

Seasonal and non-seasonal depression. A comparison of clinical characteristics in Swedish patients.

This study compares the clinical characteristics of 127 patients with major depression, 99 with a seasonal and 28 with a non-seasonal pattern. Non-seasonal depressives had significantly higher scores in the Comprehensive Psychopathological Rating Scale, and the Hamilton Depression Rating Scale. Increased appetite and carbohydrate craving, were more frequently reported among patients with a seasonal pattern. Compared to previous reports, the Swedish patients with seasonal depression had less atypical vegetative symptomatology. The symptoms sadness, suicidal thoughts, slowness of movement, gastrointestinal symptoms, and weight loss were more frequent in the patients with a non-seasonal pattern. The clinical symptomatology has a low specificity compared to the seasonal pattern in diagnosing seasonal affective disorder according to DSM-III-R for seasonal and non-seasonal patterns.

Adult↗
PubMed1987

Inverse seasonal relationship between melatonin and ovarian activity in humans in a region with a strong seasonal contrast in luminosity.

The effects of season on the activity of the pituitary-ovarian axis and the pineal gland were studied in 11 women by serum and urinary melatonin determinations and in 21 women by measurements of the serum concentrations of anterior pituitary and ovarian hormones during the dark and light seasons. A melatonin index was determined by integration of the area below the curve of serum melatonin concentrations during 24-h periods in both seasons. During the dark season, the daytime 12-h melatonin index and daytime urinary melatonin excretion were significantly higher than during the light season. In addition, the duration of the nocturnal melatonin pulse (serum melatonin levels, greater than 65 pmol/L) was lengthened during this season, whereas the mean serum estradiol concentration was significantly decreased at the time of ovulation and during the luteal phase of the cycle, indicating lowered ovarian activity. Luteal phase gonadotropin concentrations were increased during the dark season, which was also characterized by increased sex hormone-binding globulin (SHBG) and decreased free testosterone concentrations and free androgen indices (ratio of testosterone to SHBG X 700) throughout the menstrual cycle. The dark season was thus characterized by increased melatonin secretion and decreased ovarian and androgenic activities. In summary, we characterized two season-dependent hormonal phenomena. Although we did not prove any cause and effect association between melatonin and anterior pituitary-ovarian hormones, the inverse seasonal relationship in pineal gland and ovarian secretion suggests that melatonin is causally related to reproduction in humans.

Adult↗
PubMed1990

Seasonal variations in prolactin, growth hormone and thyroid hormones and the prolactin surge at ovulation do not affect litter size of ewes during pregnancy in the oestrous or the anoestrous season.

Injection of bromocriptine from 5 days before until 5 days after mating clearly suppressed the periovulatory prolactin surge in ewes in the anoestrous and oestrous season but did not change the litter size significantly. Progesterone, GH, TSH or thyroid hormone concentrations were not influenced by the bromocriptine treatment. The progesterone concentrations were lower during the first weeks after mating in the anoestrous season compared to the oestrous season, while there was no difference between pregnant and non-pregnant ewes. During later gestation this seasonal difference was only observed in the non-pregnant ewes. At the same time there was a clear difference between pregnancy and non-pregnancy in both seasons. The prolactin, GH and thyroid hormone values also varied significantly during gestation. Since these patterns are identical in pregnant and non-pregnant ewes, the fluctuations are due to environmental factors and not to pregnancy or altered progesterone concentrations. In the anoestrous season prolactin, GH, T4 and T3 levels were higher than in the breeding season, while rT3 showed the opposite pattern. The TSH concentration did not differ between the two seasons. These results suggest that seasonal variations in prolactin, GH and thyroid hormones or the periovulatory prolactin surge do not affect litter size of ewes during pregnancy in the oestrous or the anoestrous season.

Animals↗
PubMed2000

Seasonality, social zeitgebers and mood variability in entrainment of mood. Implications for seasonal affective disorder.

BACKGROUND: Seasonal variations in mood (seasonality) appear to be entrained to light, a physical zeitgeber. We hypothesised that people high in seasonality may be responsive to a range of zeitgebers, because of greater mood variability. We investigated whether the moods of people high in seasonality were more strongly entrained to the calendar week, a social zeitgeber, and whether any such effect was dependent on variability of mood. METHODS: 53 participants (14 male, 39 female; overall mean age=30) completed a daily mood report, over 56 consecutive days. Participants also completed the Seasonality Score Index (SSI) of the Seasonal Pattern Assessment Questionnaire. Each participant's time series of daily mood was analysed by spectral analysis to quantify the strength of their weekly mood cycle. RESULTS: Participants with high SSI scores (> or =11) had significantly stronger weekly mood cycles than those with low SSI scores (<11), and significantly greater variability in mood. Covarying for mood variability reduced the difference between high and low SSI groups in mean strength of weekly mood cycle to non-significance. LIMITATIONS: The time series of moods obtained was relatively short, and moods among high seasonal participants may have been affected by seasonal weather variability. CONCLUSIONS: People high in seasonality appear to be more responsive to external zeitgebers, and this could be linked to their greater variability in mood. The integration of research on mood variability with research on SAD appears to be warranted.

Adult↗
PubMed2003

The Seasonal Pattern Assessment Questionnaire as a measure of mood seasonality: a prospective validation study.

The aim of this study was to test the validity of the Seasonal Pattern Assessment Questionnaire (SPAQ) as a measure of winter pattern seasonality of mood in the general population. The criterion was four repeated measurements of mood, collected in summer and winter each year for 2 years in a longitudinal questionnaire study. To account for the imperfect reliability of SPAQ reports, the SPAQ was completed on two occasions, and aggregate SPAQ variables created. Three variables from the SPAQ were tested for their correlation with prospectively measured lowering of mood in winter: seasonal pattern type, Global Seasonality Score (GSS) and self-reported problems with seasonal variation. The sampling frame was the electoral roll in a suburban region of Melbourne, Australia. Complete four-wave data were obtained from 304 respondents (53.9% female). Seasonal pattern type (self-report as feeling worst in winter months) was the only SPAQ variable to show a significant association with prospectively measured winter pattern seasonality of mood. It is provisionally concluded that the SPAQ can function as a measure of seasonality of mood in the normal population, but that validity has only been confirmed for the relatively gross variable of seasonal pattern type.

Adult↗
PubMed2004

Effect of nasal triamcinolone acetonide on seasonal variations of bronchial hyperresponsiveness and bronchial inflammation in nonasthmatic children with seasonal allergic rhinitis.

BACKGROUND: Recent evidence suggests that patients with allergic rhinitis have lower airway inflammation and a higher prevalence of bronchial hyperresponsiveness (BHR) regardless of asthma. OBJECTIVE: To investigate markers of lower airway inflammation in nonasthmatic children with seasonal allergic rhinitis (SAR) before and during pollen season and the effect of nasal triamcinolone acetonide on seasonal variations in these parameters. METHODS: Thirty-two nonasthmatic children with SAR in response to grass and/or weed pollens were recruited and separated into 2 groups. Group 1 was treated with triamcinolone acetonide (220 microg once daily) for 6 weeks, and group 2 received no intranasal corticosteroid treatment. Bronchial responsiveness to methacholine [concentration that caused a decrease in forced expiratory volume in 1 second of 20% (PC20)], eosinophil counts in sputum and peripheral blood, and eosinophil cationic protein (ECP) levels in sputum and serum were measured before and during grass pollen season. RESULTS: Twenty-eight patients completed the study. During the pollen season, methacholine PC20 significantly decreased in both groups when compared with the corresponding preseasonal values (P = .01 and P = .003, respectively). The mean percentage of sputum eosinophils increased significantly during the pollen season compared with preseasonal values in group 1 and group 2 (12.7% +/- 2.1% vs 16.5% +/- 2.1%, P = .007, and 11.0% +/- 2.0% vs 20.2% +/- 1.4%, P = .003, respectively). Median [interquartile ranges (IQR)] sputum ECP levels were significantly higher during the pollen season when compared with the preseasonal values in group 1 and group 2 [7.5 microg/L (3.5-36.0 microg/L) vs 35.5 microg/L (13.0-71.7 microg/L), P = .04, and 18.0 microg/L (6.0-36.0 microg/L) vs 69.0 microg/L (39.0-195.0 microg/L), P = .003, respectively], as were the serum ECP levels [6.0 microg/L (2.0-13.0 microg/L) vs 19.0 microg/L (14.0-43.5 microg/L), P = .004, and 6.0 microg/L (3.0-7.0 microg/L) vs 18.0 microg/L (6.0-36.0 microg/L), P = .001, respectively]. Although the mean number of eosinophils in blood increased during the pollen season in both groups, it was only significant in group 2 (70.0 +/- 20.0 vs 161.6 +/- 29.0, P = .02). CONCLUSIONS: Although prophylactic nasal corticosteroid treatment provides significant reduction of nasal symptoms and rescue antihistamine use, there is no significant prevention in the seasonal increase of bronchial inflammation and methacholine BHR.

Adolescent↗
PubMed1998

Role of serotonin transporter promoter repeat length polymorphism (5-HTTLPR) in seasonality and seasonal affective disorder.

Seasonal variations in mood and behavior (seasonality) and seasonal affective disorder (SAD) have been attributed to seasonal fluctuations in brain serotonin (5-HT). the short (s), as opposed to the long (l), allele of the 5-HT transporter linked polymorphism (5-HTTLPR) has been associated with neuroticism and depression. We hypothesized that this short allele would also be associated with SAD and with higher levels of seasonality. Ninety-seven SAD patients and 71 non-seasonal healthy controls with low seasonality levels were genotyped for 5-HTTLPR and compared statistically. Patients with SAD were less likely to have the l/l genotype (27.8% vs 47.9%; P < 0.01) and more likely to have the s allele (44.8% vs 32.4%; P < 0.02) as compared to controls. The three 5-HTTLPR genotypes were also differentially distributed in patients and controls (P < 0.03). The SAD patients with the l/l genotype had a lower mean seasonality score than did patients with the other two genotypes (mean +/- s.d. = 15.3 +/- 2.8 vs 17.1 +/- 3.4 respectively; P < 0.02). The 5-HTTLPR short allele contributes to the trait of seasonality and is a risk factor for SAD, providing further evidence for a relationship between genetic variation in the 5-HT transporter (5-HTT) and behavior.

Affect↗
PubMed1990

Effects of maternal birth season on birth seasonality in the Canadian population during the seventeenth and eighteenth centuries.

Birth records of the French-Canadian population for the period 1621-1765 were analyzed retrospectively to examine the effect of maternal birth season on the seasonal distribution of births. Preliminary examination indicated that there was a bimodal pattern in birth seasonality: a major peak in early spring, a trough in early summer, a minor peak in autumn, and a trough around December. Because this seasonality was strongly biased at the level of the first birth by the month of marriage, which was concentrated in November, the seasonality of nonfirst births (n = 32,926) was examined in relation to the four seasons of maternal birth. Mothers born in May-July showed a flatter monthly distribution of nonfirst births at a maternal age of 28 years or more. Analysis of marriage-first birth intervals indicated that mothers who married in August-October showed a lower percentage of immediate conception (intervals of 8-10 months), whereas those mothers born in May-July had a higher percentage of immediate conception. This difference in birth seasonality shown by mothers born in May-July is similar to results from early twentieth-century Japan. Some seasonal infertility factors could have affected the embryos at the earliest stage of pregnancy, modifying a part of the seasonal variation in birth rate.

Birth Intervals↗
PubMed1996

The effects of first-season strategic and tactical ivermectin treatments on trichostrongylosis in the first- and second-season grazing.

A 2 year study was conducted to evaluate the effects of first-season strategic or tactical treatments with ivermectin on trichostrongylosis in heifer calves in the first and second-season grazing. Three groups of each eight Holstein-Friesian calves were turned out in early May onto a permanent pasture naturally contaminated with trichostrongyle larvae. Two of these groups were given ivermectin either as strategic treatments (Weeks 3, 8 and 13 after turnout) or as tactical treatments (Weeks 14, 18 and 22 after turnout); the third group served as untreated controls. The strategic ivermectin treatments prevented build-up of high herbage infectivity from mid-summer onwards as shown by low trichostrongyle egg outputs, serum pepsinogen levels and serum antibody responses. In spite of exposure to continuous high larval challenge in late season, the pathogenic effects of worm loads in calves receiving the tactical ivermectin treatment were significantly suppressed. The performance of the strategically treated calves tended to be higher than that of the tactically treated calves in the first-season grazing; yet, there was no statistical difference. During the following summer, all three groups were grazed in a single herd together with a new group of eight first-season calves. No anthelmintic treatments were given to any animals during the season. From late August until the end of the season all animals were given weekly experimental challenge infections. Following the challenge infections, the first-season calves developed clinical parasitic gastroenteritis, whereas the second-season heifers showed no symptoms. At post-mortem it was found that worm burdens mainly consisted of early fourth-stage larvae (L4) of Ostertagia ostertagi (> 97%). Fewer adult worms were recovered from the untreated animals than from the treated ones. However, serum anti-parasite IgG1 responses and post-mortem worm counts suggested that the untreated heifers harboured markedly fewer adult O. ostertagi than the previously treated ones, indicating a higher level of immunity against adult worms. However, this difference did not have any clinical impact in this experiment.

Animals↗
PubMed2001

Effects of follicle stimulating hormone (FSH) on follicular development, oocyte retrieval, and in vitro fertilization (IVF) in ewes during breeding season and seasonal anestrus.

Administration of FSH increases the number of developing follicles, and affects oocyte health and cleavage rate. To determine the optimal level of FSH treatment, studies were conducted during the normal breeding season and seasonal anestrus. In Experiment 1, ewes were implanted with SyncroMate-B (SMB; norgestomet) for 14 days during the breeding season. Beginning on day 12 or 13 after SMB implantation, ewes were treated with saline (control; n=10), or treated with FSH for two days (2D; n=9) or three days (3D; n=10). In Experiment 2, conducted during seasonal anestrus, ewes were implanted with SMB for 14 days (n=23) or were not implanted (n=26). The SMB-implanted and nonimplanted ewes were assigned to one of three treatments as in Experiment 1: control (n=13), 2D (n=21) or 3D (n=15). In Experiments 1 and 2, ewes were laparotomized to count the number of follicles < or = 3 mm and > 3 mm and to retrieve oocytes. Healthy oocytes from each treatment were used for IVF. In Experiment 3, ewes (n=6) were implanted twice with SMB for 14 days during seasonal anestrus. Ewes were injected with FSH for 2 days, and the oocytes were collected and fertilized as in Experiments 1 and 2. In Experiment 1, FSH-treatment increased (P < 0.05) the number of follicles > 3 mm, the number of oocytes retrieved from follicles < or = 3 mm and > 3 mm, the proportion of healthy oocytes, and the number of oocytes used for IVF. Oocytes from control and 2D ewes had greater (P < 0.01) cleavage rates than 3D ewes (68% and 71% vs. 42%). In Experiment 2, implanted and nonimplanted ewes had similar (P > 0.05) numbers of follicles, total oocytes, and healthy oocytes; therefore, data were combined. The FSH treatment increased (P < 0.01) the number of follicles > 3 mm, and the number of oocytes recovered from follicles > 3 mm. The recovery rate of oocytes and the percentage of healthy oocytes were similar for control and FSH-treated ewes. The cleavage rate in Experiment 2 ranged from 4 to 16%. In Experiment 3, the cleavage rate for ewes treated twice with SMB was 27% which tended to be greater (P < 0.07) than for the 2D ewes that received one SMB implant in Experiment 2. These data indicate that FSH increased the number of developing follicles and the number of healthy oocytes retrieved from ewes during the breeding season and seasonal anestrus. However, cleavage rates during seasonal anestrus were lower than during the normal breeding season in both FSH-treated and control ewes. Treatment of ewes for 2 days with FSH resulted in a greater cleavage rate than treatment of ewes for 3 days.

Anestrus↗
PubMed2000

Dry season conditions determine wet season water use in the wet-tropical savannas of northern Australia.

Daily and seasonal patterns of transpiration were measured in evergreen eucalypt trees growing at a wet (Darwin), intermediate (Katherine) and dry site (Newcastle Waters) along a steep rainfall gradient in a north Australian savanna. Relationships between tree size and tree water use were also determined. Diameter at breast height (DBH) was an excellent predictor of sapwood area in the five eucalypt species sampled along the rainfall gradient. A single relationship existed for all species at all sites. Mean daily water use was also correlated to DBH in both wet and dry seasons. There were no significant differences in the relationship between DBH and tree water use at Darwin or Katherine. Among the sites, tree water use was lowest at Newcastle Waters at all DBHs. The relationship between DBH and tree leaf area was similar between species and locations, but the slope of the relationship was less at the end of the dry season than at the end of the wet season at all locations. There was a strong relationship between sapwood area and leaf area that was similar at all sites along the gradient. Transpiration rates were significantly lower in trees at the driest site than at the other sites, but there were no significant differences in transpiration rates between trees growing at Darwin and Katherine. Transpiration rates did not vary significantly between seasons at any site. At all sites, there was only a 10% decline in water use per tree between the wet and dry seasons. A monthly aridity index (pan evaporation/rainfall) and predawn leaf water potential showed strong seasonal patterns. It is proposed that dry season conditions exert control on tree water use during the wet season, possibly through an effect on xylem structure.

Journal Article↗
PubMed1999

Nasal reactivity to capsaicin in patients with seasonal allergic rhinitis during and after the pollen season.

BACKGROUND: We aimed to study the participation of neurogenic mechanisms in nasal allergic inflammation by assessing the effect of neurogenic stimulation on the secretory and cellular responses of nasal mucosa in patients with allergic rhinitis. METHODS: A group of patients suffering from seasonal allergic rhinitis was challenged intranasally with incremental doses of capsaicin (0.3, 3, 12 microg) during and after the pollen season. Clinical symptoms after provocations were monitored, and unilateral nasal lavages were obtained. The nasal lavage fluid (NAL) was assayed for concentration of total protein, albumin, lactoferrin, and number of leukocytes, following by differential count. RESULTS: Capsaicin challenge during the pollen season produced greater congestion (P < 0.01) and rhinorrhea (P < 0.05) than after the season. The intensity of burning sensation (pain) was similar on both occasions. Capsaicin failed to increase albumin content in NAL both during and after the season. Total protein was increased only after the highest dose of capsaicin (P < 0.03) after the season. The number of eosinophils in basal lavages was higher during the season. During the season, the total number of leukocytes at least doubled in 7/12 patients and the percentage of eosinophils increased in 6/12 patients after the capsaicin challenge. CONCLUSIONS: Our study demonstrated that during the symptomatic period the nasal mucosa of allergic patients is more susceptible to neurogenic stimulation, showing enhanced secretory and inflammatory (cellular) responses.

Airway Resistance↗
PubMed2001

Responses to the Seasonal Pattern Assessment Questionnaire in different seasons.

OBJECTIVE: The study investigated whether results on the Seasonal Pattern Assessment Questionnaire, which is used for diagnosis of seasonal affective disorder, differed by the season in which the questionnaire was completed. METHOD: Every third month from March 1997 to February 1998, a population-based panel of 200 men and women age 27-72 years in Gamvik, northern Norway, completed a standardized questionnaire that included all items from the Seasonal Pattern Assessment Questionnaire. RESULTS: The average score for seasonal affective disorder changed over the year. The difference between the highest score, in March, and the lowest, in September, was 8.8%. CONCLUSIONS: Results on the Seasonal Pattern Assessment Questionnaire varied by season, but did not vary by seasonal differences in the amount of daylight.

Adult↗
PubMed2004

Seasonality of birth in seasonal affective disorder.

BACKGROUND: Season of birth or seasonal changes in putative etiologic factors are thought to influence the development of several psychiatric illnesses. The aim of this investigation was to examine seasonal differences in the frequency of birth in a clinical sample of patients with seasonal affective disorder (SAD). METHOD: 553 outpatients suffering from SAD-DSM-IV-defined depressive disorder with winter-type seasonal pattern-who had been diagnosed and treated at the Department of General Psychiatry (University of Vienna, Austria) between 1994 and 2003, were included in this evaluation. We compared the observed number of births in our sample with expected values calculated from the general population. RESULTS: There was a significant deviation of the observed number of births from the expected values calculated on a monthly basis (p = .009). When comparing quarters (periods of 3 months), we found fewer births than expected in the first quarter of the year and a slight excess of births in the second and third quarters (p = .034). There were also more births in the spring/summer season and fewer than expected in fall and winter (p = .029). Interestingly, patients with melancholic depression were more frequently born in fall/winter and less often in spring/summer compared with patients with atypical depression (p = .008). CONCLUSION: Besides genetic factors, season of birth or seasonal changes in environmental factors also could influence the development of SAD. In addition, birth effects seem to be dependent on the symptom profile of the patients, but further studies are needed to elucidate the underlying mechanisms of these observations.

Adult↗
PubMed2001

Seasonal growth of song control nuclei precedes seasonal reproductive development in wild adult song sparrows.

In seasonally breeding adult songbirds, the brain regions that control song undergo dramatic seasonal morphological changes. During late winter and early spring, increasing day length triggers an increase in circulating testosterone that ultimately causes several song nuclei to grow in volume. The timing of this growth relative to the seasonal development of the reproductive system is not known. This question was investigated in two populations of wild song sparrows (Melospiza melodia morphna). Both populations live at the same latitude (46 degrees N), but breed at different altitudes. One population resides on the Pacific coast in Washington, and the other resides in the foothills of the Cascade Mountains. Both populations experienced the same photoperiodic conditions, but the timing of seasonal reproductive development differed between populations. Coastal birds initiated gonadal recrudescence approximately 2 weeks earlier than montane birds. Despite this temporal difference in reproductive development, there were no differences between these groups in the seasonal growth of two song control nuclei, HVc and RA. During late February, both groups had low circulatory levels of testosterone (mean for coastal birds was 1.01 +/- 0.37 ng/ml; mean for montane birds was 1.41 +/- 0.26 ng/ml) and fully recrudesced song nuclei (for example, mean HVc volume in coastal birds was 1.77 +/- 0.08 mm(3); mean HVc volume in montane birds was 1.76 +/- 0.09). Also at this time, both populations were in the earliest stages of seasonal reproductive development as judged by the degree of gonadal recrudescence (mean gonad volume was less than 10% of typical breeding size in both populations). It is concluded that seasonal song system growth is completed before seasonal reproductive development in response to submaximal levels of circulating testosterone.

Animals↗
PubMed1994

Evidence for a seasonal form of recurrent brief depression (RBD-seasonal).

We have established a relationship between recurrent brief depression (RBD) and seasonal affective disorder (SAD) in a cohort of 42 outpatients who presented themselves at a clinic for seasonal affective disorder at the Psychiatry Department of the University of Bonn, Germany. Our preliminary data indicate that 31% of the patients who were diagnosed as suffering from either SAD or its subsyndromal form (S-SAD) can also be categorized as RBD (RBD-seasonal) for a 1-year observation period. During the time span of 1 year, RBD-seasonal patients had a mean number of 20 +/- 9 episodes, which were accentuated in fall/winter, outnumbering the ones in spring/summer significantly (P < 0.001). The mean duration of each episode was 4.6 +/- 2.6 days in the RBD-seasonal group. RBD-seasonal patients experienced seasonal changes as more of a problem and reported a lower percentage of first-degree relatives with a history of depression than the non-RBD-seasonal group.

Adult↗
PubMed1988

Relative contributions of late dry-season and early rains pasture contaminations with trichostrongyle eggs to the wet-season herbage infestation in eastern Nigeria.

Two worm-free grass paddocks, P1 and P2, were artificially contaminated in March and April-May, respectively, with bovine faeces containing known numbers of trichostrongyle (mainly Cooperia, Haemonchus and Trichostrongylus spp.) eggs in order to determine the relative contributions of late dry-season and early rains pasture contaminations to the wet-season herbage larval infestation in Nsukka, eastern Nigeria. The resulting herbage infestation was assessed by means of larval counts and tracer studies. A sudden rise in herbage infestation occurred simultaneously in both paddocks in late April, this apparently being determined by the onset of the first substantial rainfall of the wet season. Peak infestations in both paddocks also occurred simultaneously in May. The infestation in P1 was much larger, and the larval population persisted longer, than that in P2 and later gave rise to a second smaller peak in June. No L3 were recovered in herbage samples from either of the paddocks after the third week of July. Both paddocks were infective to goats in May-June, while P2 was also infective in July-August. The results suggest that in the Nigerian derived savanna the initial wet-season herbage infestation in pastures grazed by infected cattle during the dry and wet seasons will consist of L3 from late dry-season and early rains pasture contaminations, the former being the major contributor to the infestation. Consequently, pastures contaminated during the late dry season may not be safe for susceptible animals to graze at the start of the succeeding rainy season.

Ancylostomatoidea↗
PubMed2004

A dual vulnerability hypothesis for seasonal depression is supported by the seasonal pattern assessment questionnaire in relation to the temperament and character inventory of personality in a general population.

BACKGROUND: Personality structure obtained from the psychobiological Temperament and Character Inventory (TCI) was studied in relation to self-reported seasonal variations in mood and behavior measured by the Seasonal Pattern Assessment Questionnaire (SPAQ). METHODS: The subjects comprised 1761 adults (57.6% women) in the age range 35-85 years, enrolled in the Betula prospective random cohort study of Umea, Sweden. RESULTS: Personality profiles of subjects who reported the occurrence of a high degree of seasonal variation as such were associated with a combination of high self-transcendence (ST) and high persistence (PS), irrespective of the level of harm avoidance (HA). Subjects who reported feeling worst in winter were associated with high HA, irrespective of the levels of ST and PS. Also, subjects feeling worst in summer or experiencing overall problems with seasonal variation were associated with high HA in their personality profiles. Using the SPAQ criteria to define seasonal affective disorder (SAD) or subsyndromal SAD (S-SAD), subjects with these disorders often had combinations of high self-transcendence (ST) and high persistence (PS), but with different associations with HA. LIMITATIONS: No evaluations were made for SAD or subsyndromal SAD according to the DSM-IV or ICD 10 criteria. CONCLUSIONS: Our results relating SPAQ with TCI give support for a dual vulnerability hypothesis for seasonal depression proposed in the literature, where it is attributed to a combination of a seasonal factor and a depression factor. Examining the literature regarding the relationships between the different TCI scales and monoamine neurotransmitter functions, those relationships suggest that these two vulnerability factors for seasonal depression may be modulated by different neurotransmitter systems.

Adult↗