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Biomedical subjects

R W Lam

Publications and source records attributed to R W Lam.

At least 73 records · Page 4Linked to original sources
PubMed1994

Morning light therapy for winter depression: predictors of response.

Bright-light therapy is widely regarded as an effective treatment for winter seasonal affective disorder (SAD). We attempted to identify predictors of light therapy response in 54 depressed, drug-free outpatients diagnosed with SAD by DSM-III-R criteria. After a baseline week, patients were treated for 2 weeks with 2500-lx cool-white fluorescent light exposure from 0600 to 0800 daily. The results showed that light therapy significantly reduced depression scores. Several indices of atypical and typical symptoms correlated with response, but none was clearly superior to the pre-treatment depression score. A multiple regression analysis identified 3 factors (hypersomnia, increased eating and younger age) that predicted light-therapy response. These results suggest that specific symptoms of hypersomnia and hyperphagia are predictors of response to morning bright-light therapy in SAD.

Adult↗
PubMed1994

A controlled study of light therapy for bulimia nervosa.

OBJECTIVE: Winter worsening of mood and eating symptoms, similar to that of seasonal affective disorder, has recently been reported in patients with bulimia nervosa. To assess the effectiveness of light therapy for treatment of bulimia nervosa, the authors conducted a study of light therapy during winter comparing an active (bright white light) condition to a control (dim red light) condition in bulimic patients who were not selected for a seasonal pattern of bulimia. METHOD: After a 2-week baseline assessment, 17 female patients with a DSM-III-R diagnosis of bulimia nervosa underwent early morning light treatment with 2 weeks of bright white light exposure (10,000 lux for 30 min/day) and 2 weeks of dim red light exposure (500 lux for 30 min/day) in a counterbalanced, crossover design. Outcome measures included daily binge/purge diaries, objective and subjective measures of mood, and the Eating Attitudes Test. Expectation of response for each condition was also assessed before treatment. RESULTS: Although pretreatment expectation ratings were similar for each condition, the bright white light condition was superior to the dim red light condition for all mood and eating outcome measures. Patients with "seasonal" bulimia (N = 7) had significantly greater improvement after the bright white light treatment than patients with nonseasonal bulimia (N = 10). No significant order effects were noted, nor differential effects for patients taking concurrent antidepressant medications (N = 4). CONCLUSIONS: These data suggest that bright white light therapy is an effective short-term treatment for both mood and eating disturbances associated with bulimia nervosa, although the therapeutic effect may be greater in those patients with a seasonal pattern.

Adult↗
PubMed1994

Research funding of psychiatric disorders in Canada: a snapshot, 1990-1991.

Although mental illness accounts for up to 14% of total direct health care costs and an estimated cost of over five billion dollars annually, research funding of psychiatric disorders is regarded as underfunded relative to other biomedical research. This study was conducted to determine the amount of funds allotted to the research of specific psychiatric disorders in Canada. Data was obtained from a national database of peer-reviewed health research funding. Based on the title of the research grant, all projects that pertained to psychiatric disorders were identified and classified according to diagnosis. Research funding for psychiatric disorders totalled $16,391,000 from 1990 to 1991, or 3.7% of all biomedical research funding for that period. The relative contributions of federal, provincial and private (nonprofit) agencies to the funding total were 54%, 39% and 8%, respectively. Research funding for mental illness remains disproportionately low relative to other medical illnesses. The role of private nonprofit agencies, in particular, is much more limited for psychiatric disorders than for other identified medical illnesses. These data suggest that increased attention to research advocacy is required to increase psychiatric research support. Advocacy strategies should include: 1. publicizing the value and scope of psychiatric research in Canada; 2. working to de-stigmatize mental illness; 3. strengthening personal and professional affiliations with patient advocacy groups; 4. increasing the number and the qualifications of psychiatric researchers; 5. improving the scientific quality of research programs; and 6. organizing national research collaborations.

Canada↗
PubMed1993

Eating attitudes in seasonal affective disorder and bulimia nervosa.

Markedly increased appetite and eating are commonly found in seasonal affective disorder (SAD) and bulimia nervosa (BN). To investigate dysfunctional eating attitudes, we administered the Eating Disorders Inventory (EDI), a self-rating questionnaire that assesses abnormal eating attitudes and behaviours, to 30 female SAD patients, 30 matched BN patients, and 30 non-clinical subjects. The SAD patients had higher scores on most EDI subscales compared to the non-clinical subjects; the BN patients had higher scores than the SAD patients on only two of three EDI subscales that are specific to eating disorders. These data add to the evidence supporting a clinical overlap between SAD and BN.

Adult↗
PubMed1993

Light visor treatment for seasonal affective disorder: a multicenter study.

The effectiveness of light therapy in seasonal affective disorder (SAD) was evaluated in 105 subjects across five centers. Three intensities of light (60 lux, 600 lux, and 3500 lux) were used in a 2-week randomized, parallel design. There was no significant difference in antidepressant efficacy of the three intensities of light. All three intensities produced a similar frequency of antidepressant response to each other and to that reported in previous studies. There were site differences in the severity of depression during light treatment, but diagnosis and medication status did not affect antidepressant response. These findings suggest that light therapy has an antidepressant action by a nonspecific effect or that light is biologically active in the treatment of SAD across a wide range of intensities.

Adult↗
PubMed1993

Depressive symptoms and family history in seasonal and nonseasonal mood disorders.

OBJECTIVE: The authors' goal was to compare the symptoms and family history of seasonal affective disorder with those of nonseasonal mood disorders. METHOD: From a subspecialty mood disorders clinic, 34 patients with major depression, seasonal pattern (seasonal affective disorder), diagnosed with DSM-III-R criteria, were matched in age, sex, and diagnostic subtype (recurrent unipolar, bipolar I, or bipolar II) to 34 patients with nonseasonal mood disorders. Data on symptoms during the most recent depressive episode were obtained by chart review and compared by using chi-square tests. Family history data for first-degree relatives of patients with seasonal and nonseasonal mood disorders were gathered by using the family history method, and diagnoses were based on Family History Research Diagnostic Criteria. RESULTS: Patients with seasonal affective disorder reported significantly more hypersomnia, hyperphagia, and weight gain and reported less suicidal ideation and morning worsening of mood than the patients with nonseasonal mood disorders. No differences were found in family histories of mood disorders, other psychiatric disorders, and any psychiatric disorder between the groups with seasonal versus nonseasonal mood disorders. Alcoholism was found more frequently in the relatives of the patients with seasonal affective disorder. CONCLUSIONS: Differences in symptoms between seasonal and nonseasonal mood disorders provide some support for seasonal affective disorder as a diagnostic subtype of mood disorders. However, the genetic loading for mood disorders (of unspecified seasonality), as determined by the family history method, is similar for seasonal and nonseasonal mood disorders.

Adult↗
PubMed1993

Side effects of light therapy in seasonal affective disorder.

The authors report the frequency of side effects of light therapy in 105 patients with seasonal affective disorder treated with three intensities of light. Common symptoms to emerge during treatment were headache (19%), eyestrain (17%), and feeling "wired" (14%). There was no relationship between side effects and intensity of light used.

Female↗
PubMed1993

Chronic schizophrenia and idiopathic Parkinson's disease.

A case is reported of a patient with autopsy-confirmed idiopathic Parkinson's disease in addition to chronic paranoid schizophrenia. Difficulties in the diagnosis and management of these two conditions are described. Because of the treatment implications, clinicians should be aware that idiopathic Parkinson's disease and schizophrenia can coexist.

Aged↗
PubMed1993

Obtaining a family psychiatric history: is it worth the effort?

The purpose of this study was to determine whether, for first-degree relatives of patients presenting to a mood disorders clinic, family history information on psychiatric conditions collected by a psychiatrist and incorporated into the patient's medical records is as informative as that gathered during an interview specifically designed to collect family history data. The study group consisted of 472 first-degree relatives of 78 randomly selected index cases from a large mood disorders genetic database. Family history of psychiatric disorders recorded in regular psychiatric medical records ("clinician history"), and data obtained by a genetic counsellor administering specific family psychiatric history questionnaires to patients and multiple family informants ("family history") were compared using a kappa statistic. Good agreement between the two methods on the presence or absence of a psychiatric disorder was found among first-degree relatives of index cases, but poor agreement was found with respect to the presence or absence of a specific mood disorder diagnosis(es) in a relative. The results suggest that a clinician-generated family psychiatric history is sensitive to the presence or absence of a psychiatric disorder when compared to a more structured detailed genetic interview. However, for research purposes, a clinician-generated family psychiatric history of a specific mood disorder diagnosis, without supporting collateral information, may not be reliable for use in supporting a mood disorder diagnosis in a patient and/or his relatives.

Adult↗
PubMed1992

The effects of ultraviolet-A wavelengths in light therapy for seasonal depression.

Although light therapy is a recognized effective treatment for seasonal affective disorder (SAD), there has been little research into the critical wavelengths of light that produce the antidepressant effect. Previous studies found conflicting results for the importance of the ultraviolet (UV) spectrum in the therapeutic effect of light therapy. To assess the clinical effects of UV-A wavelengths (315-400 nm), we studied 33 depressed SAD patients diagnosed with structured interviews by DSM-IIIR criteria. Following a baseline week, patients underwent 2 weeks of 2500 lux light therapy for 2 h daily (06:00-08:00). Light therapy consisted of cool-white fluorescent light with the addition of a special UV-A fluorescent tube. Patients were randomized to wear glasses during light therapy that either blocked (UV-blocked condition) or passed (UV-A condition) wavelengths below 400 nm. Both treatments significantly reduced all depression ratings, but no differences were found between the UV-A and UV-blocked conditions. We conclude that the UV-A spectrum does not increase the antidepressant response of light therapy. Given the potential side effects of chronic UV exposure, clinical application of light therapy should use light sources that have the UV spectrum filtered.

Adult↗
PubMed1992

Electroretinography in seasonal affective disorder.

Retinal mechanisms have been hypothesized in the pathophysiology of seasonal affective disorder (SAD). Electroretinography (ERG) is a noninvasive electrophysiologic test that provides an objective measure of photoreceptor and retinal function. We conducted dark-adapted ERG examinations with a bright white light stimulus in a group of depressed, drug-free patients with seasonal affective disorder (6 men, 18 women) diagnosed by DSM-III-R criteria, and a group of sex- and age-matched control subjects (6 men, 16 women) during the winter. A significant difference was found between SAD patients and controls, but female SAD patients had lower ERG b-wave amplitudes than female controls, while male SAD patients had higher amplitudes than the matched controls. The ERG b-wave implicit times (times from onset of stimulus to peak of b-wave) were significantly longer in the left eyes of the male control subjects. These data may indicate subtle retinal changes in patients with SAD, but the results must be considered preliminary because of the small number of subjects studied and the large intersubject variability in the ERG procedure.

Adult↗
PubMed1991

Thyrotropin-releasing hormone in ovine fetus: ontogeny and effect of thyroid hormone.

The ontogenesis of hypothalamic and extrahypothalamic thyrotropin-releasing hormone (TRH) and the effect of altered thyroid status on tissue TRH levels were studied in fetal sheep. At 62 days gestation (term = 145 days) TRH was detectable in serum and in hypothalamic, placental, and pancreatic tissues; pancreatic, placental, and serum levels exceeded hypothalamic levels two- to fivefold. Analysis of tissues obtained from 88-day gestation fetuses were comparable: TRH levels in placenta (54 +/- 15 pg/mg tissue protein), pancreas (34 +/- 5 pg/mg protein), and serum (93 +/- 9 pg/ml) exceeded those in hypothalamic extracts (15 +/- 9 pg/mg protein). By 120 days gestation, TRH values in the hypothalamus (610 +/- 52 pg/mg protein) exceeded those in extrahypothalamic sites; values were comparable at 140 days gestation. Fetal thyroidectomy resulted in a 2-fold elevation of hypothalamic TRH concentrations (1,030 +/- 139 vs. 522 +/- 29 pg/mg protein) and 2 to 20-fold elevations of TRH in the placenta (147 +/- 23 vs. 42 +/- 8 pg/mg protein), pancreas (195 +/- 11 vs. 29 +/- 7 pg/mg protein), duodenum (363 +/- 97 vs. 29 +/- 7 pg/mg protein), and serum (2,563 +/- 212 vs. 131 +/- 16 pg/ml). 3, 5, 3'-Triiodothyronine (T3) infusion in thyroidectomized fetuses resulted in elevated serum T3 values (480 +/- 80 ng/dl) and suppressed hypothalamic TRH (249 +/- 68 vs. 522 +/- 29 pg/mg protein) and serum TRH concentrations (30 +/- 4 vs. 131 +/- 156 pg/ml). Placental, pancreatic, and duodenal TRH concentrations in thyroidectomized T3-infused animals were below the level of detection of the assay (5 pg/mg tissue protein).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Low electrooculographic ratios in patients with seasonal affective disorder.

OBJECTIVE: Changes in retinal sensitivity to light have been hypothesized as etiological in seasonal affective disorder. This study was undertaken to investigate sensitivity to light in seasonal affective disorder using electrooculography (EOG), an objective measure of retinal light response. METHOD: In a mood disorders clinic, 19 depressed, drug-free patients with seasonal affective disorder, diagnosed by DSM-III-R criteria, were compared with 19 age- and sex-matched normal comparison subjects. All subjects had identical EOG testing performed during the winter. EOG (Arden) ratios were calculated from the EOG data. RESULTS According to multivariate analysis of variance, the EOG ratios in the patients with seasonal affective disorder were significantly lower than those of the normal comparison subjects, although there was considerable overlap in EOG ratios between patients and comparison subjects. CONCLUSIONS: These results suggest that seasonal affective disorder is associated with subtle retinal abnormalities at the level of the photoreceptor/retinal pigment epithelium complex, consistent with subsensitivity to light. A limitation of this study is that the retinal origins of the EOG response are nonspecific and still not completely elucidated.

Adult↗