Tryptophan hydroxylase 2 in seasonal affective disorder: underestimated perspectives?

2015 ◽  
Vol 26 (6) ◽  
Author(s):  
Alexander V. Kulikov ◽  
Nina K. Popova
Keyword(s):  
Affective Disorder ◽  
Tryptophan Hydroxylase ◽  
Seasonal Affective Disorder ◽  
Recurrent Depression ◽  
Tryptophan Hydroxylase 2 ◽  
System Functioning ◽  
Brain Neurotransmitter ◽  
The Relationship ◽  
Rate Limiting ◽  
The Brain

AbstractSeasonal affective disorder (SAD) is characterized by recurrent depression occurring generally in fall/winter. Numerous pieces of evidence indicate the association of SAD with decreased brain neurotransmitter serotonin (5-HT) system functioning. Tryptophan hydroxylase 2 (TPH2) is the key and rate-limiting enzyme in 5-HT synthesis in the brain. This paper concentrates on the relationship between TPH2 activity and mood disturbances, the association between human

Melatonine en stemmingsstoornissen

1995 ◽  
Vol 7 (3) ◽  
pp. 75-79
Author(s):  
J. Beullens
Keyword(s):  
Pineal Gland ◽  
Affective Disorder ◽  
Premenstrual Syndrome ◽  
Affective Disorders ◽  
Seasonal Affective Disorder ◽  
Bright Light ◽  
Light Therapy ◽  
Melatonin Level ◽  
Melatonin Secretion ◽  
The Relationship

SummaryMelatonin is a hormone secreted by the pineal gland mainly during the night. The discovery that this melatonin secretion decreases under the influence of bright light, gave rise to the use of light therapy in some affective disorders. The literature on the relationship between melatonin secretion and mood is reviewed concerning seasonal affective disorder, non-seasonal affective disorder and premenstrual syndrome. Light therapy could reduce an abnormal high melatonin secretion back to normal proportions. None of the affective disorders, however, is accompanied by an unusual high melatonin level. Nevertheless, light therapy as well as other therapies that suppress melatonin have a therapeutic effect. This is not the case with the administration of melatonin. Mood is not affected by extra melatonin in seasonal affective disorder but it is in both other affective disorders. Melatonin plays a part in the pathogenesis of the affective disorders but it is not yet clear which one.

scholarly journals Effects of pyridoxine deficiency and dl-p-chlorophenylalanine administration to rats on 5-hydroxytryptamine and noradrenaline concentrations in brain and 5-hydroxytryptamine concentration in blood

1973 ◽  
Vol 134 (3) ◽  
pp. 763-767 ◽  
Author(s):  
Hemmige N. Bhagavan ◽  
David B. Coursin
Keyword(s):  
Body Weight ◽  
Gastrointestinal Tract ◽  
Tryptophan Hydroxylase ◽  
Marked Decrease ◽  
Brain Weight ◽  
Pyridoxine Deficiency ◽  
Weanling Rats ◽  
And Control ◽  
Rate Limiting ◽  
The Brain

Pyridoxine deficiency in post-weanling rats caused a marked decrease in body weight and a small but significant decrease in brain weight. Although the concentration of circulating 5-hydroxytryptamine was markedly decreased, the concentrations of 5-hydroxytryptamine and noradrenaline in the brain were not affected. p-Chlorophenylalanine, an inhibitor of 5-hydroxytryptamine synthesis, decreased the 5-hydroxytryptamine content of brain to very low values in both the deficient and control animals, whereas the noradrenaline contents were not appreciably affected. The concentration of 5-hydroxytryptamine in blood, the origin of which is primarily gastrointestinal, was decreased only in the controls but not in the deficient animals after p-chlorophenylalanine treatment. These results suggest that whereas l-tryptophan hydroxylase (EC 1.14.3.2) is rate-limiting in the brain as has been reported by others, the pyridoxal 5′-phosphate-dependent enzyme 5-hydroxytryptophan decarboxylase (EC 4.1.1.28) may be more important in the gastrointestinal tract in the regulation of 5-hydroxytryptamine synthesis.

What is this thing called “SAD”? A critique of the concept of seasonal affective disorder

2008 ◽  
Vol 17 (2) ◽  
pp. 120-127 ◽  
Author(s):  
Vidje Hansen ◽  
Ingunn Skre ◽  
Eiliv Lund
Keyword(s):  
Affective Disorder ◽  
Seasonal Affective Disorder ◽  
Seasonal Pattern ◽  
Relevant Literature ◽  
Large Population ◽  
Recurrent Depression ◽  
Northern Norway ◽  
Prevalence Of Depression ◽  
Icd 10 ◽  
General Populations

SummaryBackground– Seasonal Affective Disorder (SAD) is supposed to be caused by lack of daylight in winter. Yet the population of Northern Norway, living without sun for two winter months, does not spontaneously complain about depression during the dark period.Aims– To summarize research bearing upon the validity of the concept of SAD.Method– Review of relevant literature concerning the epidemiology of SAD and the questionnaire developed to measure it in general populations, the Seasonal Pattern Assessment Questionnaire (SPAQ).Results– Large population studies from northern Norway do not point to a higher prevalence of depression in winter than expected in any other general population. The psychometric properties of SPAQ are rather poor, and the diagnosis of SAD based on SPAQ bears little relationship to a meaningful concept of depression.Conclusions– Seasonal Affective Disorder is not a valid medical construct. Instead, “Recurrent depression with seasonal pattern” as defined in the DSM-IV and the ICD-10 should be used as terms. However, more research is needed to establish whether it is at all fruitful to single out such a subtype of recurrent depression.Declaration of Interest: None.

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