Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Animal data indicate that serotonin (5-HT) is a major neurotransmitter involved in the control of numerous central nervous system functions including mood, aggression, pain, anxiety, sleep, memory, eating behavior, addictive behavior, temperature control, endocrine regulation, and motor behavior. Moreover, there is evidence that abnormalities of 5-HT functions are related to the pathophysiology of diverse neurological conditions including Parkinson's disease, tardive dyskinesia, akathisia, dystonia, Huntington's disease, familial tremor, restless legs syndrome, myoclonus, Gilles de la Tourette's syndrome, multiple sclerosis, sleep disorders, and dementia. The psychiatric disorders of schizophrenia, mania, depression, aggressive and self-injurious behavior, obsessive compulsive disorder, seasonal affective disorder, substance abuse, hypersexuality, anxiety disorders, bulimia, childhood hyperactivity, and behavioral disorders in geriatric patients have been linked to impaired central 5-HT functions. Tryptophan, the natural amino acid precursor in 5-HT biosynthesis, increases 5-HT synthesis in the brain and, therefore, may stimulate 5-HT release and function. Since it is a natural constituent of the diet, tryptophan should have low toxicity and produce few side effects. Based on these advantages, dietary tryptophan supplementation has been used in the management of neuropsychiatric disorders with variable success. This review summarizes current clinical use of tryptophan supplementation in neuropsychiatric disorders.
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PMID:L-tryptophan in neuropsychiatric disorders: a review. 130 30

The risk for depression increases at two opposite times of the year--late spring/early summer and late fall/early winter. In 15% of patients with recurrent major depression, depressive episodes regularly recur on an annual basis in one of the two seasonal risk periods. Thus, there are primarily two forms of seasonal affective disorder: recurrent fall-winter depression and recurrent spring-summer depression. The opposite seasonal types of depression tend to have opposite vegetative symptoms. Sleep, appetite and weight increase in winter depression and decrease in summer depression. An important implication of the seasonality of depression is that some type of depression may be caused by changes in the physical environment and that manipulations of the physical environment may be used as treatments. There is now extensive evidence that exposure to bright artificial light is an effective treatment of recurrent winter depression. A corollary is that seasonal deficiency of natural light probably induces winter depression. There have been considerable efforts to elucidate the biological mechanisms of winter depression and its response to phototherapy. Although no single system has been shown to be responsible for the syndrome, there is evidence that the indole hormone melatonin, the indole neurotransmitter serotonin, and the peptide neurohormone corticotropin releasing hormone (CRH) play roles in the pathophysiology and phototherapy of winter depression.
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PMID:Seasonal vulnerability to depression. Implications for etiology and treatment. 130 42

Seasonal affective disorder is characterized by recurrent winter depression associated with hypersomnia, overeating, and carbohydrate craving. The severe form of winter depression affects about 5% of the general population and is believed to be caused by light deficiency. About 70%-80% of patients with winter depression experience attenuation of symptoms when exposed to bright light therapy. Hypotheses pertaining to the pathogenesis of winter depression implicate the effects of light on different characteristics of circadian rhythms. One of the environmental factors which may be implicated, in addition to light, in the pathophysiology of winter depression is the geomagnetic field. There is strong indication that the pineal gland is a magnetosensitive system and that changes in the ambient magnetic field alter melatonin secretion and synchronize the circadian rhythms. In man, shielding of the ambient magnetic field significantly desynchronizes circadian rhythms which could be gradually resynchronized after application of magnetic fields. The strength of the environmental magnetic field diminishes during the winter months, leading to increased susceptibility for desynchronization of circadian rhythms. Thus, since the acute application of magnetic fields in experimental animals resembles that of acute exposure to light with respect to melatonin secretion (i.e., suppression of melatonin secretion), magnetic treatment might be beneficial for patients with winter depression. In addition, since the environmental light and magnetic fields, which undergo diurnal and seasonal variations, influence the activity of the pineal gland, we propose that a synergistic effect of light and magnetic therapy in patients with winter depression would be more physiological and, therefore, superior to phototherapy alone.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Magnetic fields and seasonality of affective illness: implications for therapy. 136 47

Recurrent brief depression (RBD) and seasonal affective disorder (SAD) have been both recently described as subgroups of major depression (DSM-III-R). We have established a relationship between these two syndromes in a cohort of 42 outpatients who presented themselves to a clinic for seasonal affective disorder at the Psychiatric Department of the University of Bonn, FRG. 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) in a 1-year observation period. During the time span of 1 year RBD-seasonal patients had a mean number of 20 (SD 9) episodes compared with 6 (SD 5) episodes (P less than 0.001) in the group of seasonal patients without BRD. These episodes were accentuated in fall/winter and outnumbered those in spring/summer significantly (P less than 0.001). The mean duration of each episode was 4.6 (SD 2.6) days in the RBD-seasonal group and 21.8 (SD 29) in the non-RBD-seasonal group. Patients with RBD-seasonal 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.
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PMID:Recurrent brief depression and its relationship to seasonal affective disorder. 139 Sep 51

Six patients with bipolar II seasonal affective disorder (SAD) and seven normal control subjects rated their moods in winter at six fixed times each week-day during 1 week of dim and 2 weeks of bright light. The scales rated represent the mood dimension specifically associated with depression, a dimension here called behavioral engagement (BE). Compared with controls, depressed SAD subjects (1) showed lower BE levels across all rating times of the day, (2) were more likely to show diurnal variation in BE, (3) displayed more between-day instability in BE diurnal rhythm, and (4) exhibited greater short-term lability (change within 3 hours) in BE. Bright light reduced or eliminated all group differences in BE level and variability.
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PMID:Behavioral engagement level, variability, and diurnal rhythm as a function of bright light in bipolar II seasonal affective disorder: an exploratory study. 141 70

The principles of photobiology suggest that the antidepressant effect of phototherapy depends on the dose and spectrum of light. We investigated the effect of spectrum by comparing two broad spectrum fluorescent light sources with different spectral distributions. In a crossover design, 11 patients with seasonal affective disorder (SAD) were treated with broad spectrum fluorescent and cool white light for 7 days. Scores on the Hamilton Rating Scale for Depression were reduced from 22.5 to 8.1 with broad spectrum fluorescent light and from 23.5 to 8.8 with cool white light. The results suggest that both light sources are effective treatments.
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PMID:Phototherapy with broad spectrum white fluorescent light: a comparative study. 141 72

We studied 32 patients with winter seasonal affective disorder (SAD) in a counterbalanced crossover design comparing 1 h of morning light treatment (about 7000 lux) to 1 h of morning placebo treatment (deactivated negative ion generator). Both treatments significantly reduced depression ratings, but there was no difference between the antidepressant response to light and to placebo. Several possible explanations for this result were discussed including an inadequate 'dose' of light (e.g., ineffective duration or intensity), an unusual sample of patients, and a placebo mechanism.
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PMID:A placebo-controlled trial of light treatment for winter depression. 147 33

At least three categories of atypical depression have been described. The hysteroid dysphoria is characterized by repeated episodes of depressed mood in response to feeling rejected, and a craving for sweets and chocolate. Two other issues are characterized by a cyclical occurrence of changes of mood and appetite, i.e., the late luteal phase dysphoric disorder (DSM-III-R, appendix), or "the premenstrual syndrome" (PMS), and the major depression with seasonal pattern (DSM-III-R), or seasonal affective disorder (SAD). The reactive mood changes are frequently accompanied by features as hypersomnia, lethargy and increased appetite, particularly with a preference for carbohydrates. Central serotonin pathways participate in the regulation of mood and behavioural impulsivity, and modulate eating patterns qualitatively and quantitatively. Depressives with PMS og SAD benefit, in general, from treatments with serotonin potentiating drugs, suggesting that brain serotonin plays a role in the pathophysiology. Ingestion of carbohydrates increases the plasma ratio of tryptophan to other large neutral amino acids in man and animal, and the serotonin synthesis in the rat brain. Based on these findings it has been suggested that the excessive carbohydrate intake by patients with PMS and SAD reflects a self-medication that temporarily relieves the vegetative symptoms via an increased central serotonergic activity.
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PMID:Serotonin, carbohydrates, and atypical depression. 148 May 61

Seasonal affective disorder is a form of depression which recurs at the same time of the year. Exposure to bright artificial light at a dose of 2,500 lux is used to treat seasonal affective disorders. We exposed a pigmented (Brown Norway) and a nonpigmented (Sprague-Dawley) rat strain with bright artificial light for 21 days at two doses (2,500 and 6,100 lux) and analyzed dopamine, dihydroxyphenyl-acetic acid, 5-hydroxytryptamine (5-HT), and 5-hydroxyindole-acetic acid (5-HIAA) by high performance liquid chromatography (HPLC) and electrochemical detection in eight different brain regions. Furthermore, we measured tissue levels of substance P (SP), neurokinins (NK), vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), and neuropeptide Y (NPY) with radioimmunoassay. Our data obtained with light microscopy show that bright artificial light at both doses induced a massive destruction of photoreceptors in the retina of albino rats but not of the pigmented rat strain. Retinal lesion of photoreceptors resulted in increased tissue levels of all measured neuropeptides except SP in the hypothalamus and increased VIP in the ventral tegmental area/substantia nigra. Furthermore, increased 5-HT and 5-HIAA tissue levels were found in the ventral tegmental area/substantia nigra. In contrast, in the frontal cortex there was a significant reduction in 5-HIAA tissue levels and a decreased 5-HIAA/5-HT ratio, indicating decreased 5-HT metabolism. Light exposure of the pigmented rat strain revealed no changes in the measured biogenic amines and neuropeptides in any investigated brain region. Our data suggest that retinal lesion but not direct visual neurotransmission induced changes in neurotransmitters in some brain regions. We conclude that Brown Norway rats but not Sprague-Dawley rats are useful to study neurochemical effects of bright artificial light. However, Sprague-Dawley rats may be a useful tool to study biochemical mechanisms of photoreceptor damage by bright light.
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PMID:Effects of bright artificial light on monoamines and neuropeptides in eight different brain regions compared in a pigmented and nonpigmented rat strain. 152 5

We examined data from 44 women with seasonal affective disorder (SAD) to determine whether any demographic, diagnostic, or symptomatic characteristics would be predictive of a favorable response to phototherapy. Preexistent hypersomnia was particularly associated with lessening of depression after phototherapy. In contrast to a report elsewhere, both "typical" and "atypical" depressive symptoms correlated with improvement after phototherapy.
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PMID:Predictors of response to phototherapy in seasonal affective disorder. 154 95


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