Replication | |||
Serotonergic marker | Aa | Bb | Putative serotonergic mechanism |
Lower plasma L-TRP and L-TRP/CAA | S | - / + + + | Lowered availability of L-TRP |
Higher plasma TRP clearance after TRP loading |
S | - / + + | Lowered availability of L-TRP through excessive peripheral catabolism |
Higher urinary xanthurenic acid excretion after TRP loading |
S | - / + | Induction of liver pyrrolase-nicotinamide pathway |
Lower plasma TRP in relation to clinical response to serotonergic antidepressants |
IS | + + + | Lower TRP availability predicts favorable outcome to serotonergic drugs |
Induction of depressive symptoms by TRP depletion techniques |
S | + + | Lowered TRP availability is related to depressive phenomenology |
Lower platelet 5-HT uptake | S | - -/+ + | Indicative of lower 5-HT transporter |
Lower platelet imipramine binding | S | - -/+ + + | Indicative of lower 5-HT transporter |
Lower platelet paroxetine binding | S | - - | No indication of abnormal 5-HT transporter |
Lower platelet or plasma 5-HT levels | S | + | Indicative of lower 5-HT storage or release |
Lower postmortem brain TRP, 5-HT, 5-HIAA | S | - / + | Lower central 5-HT turnover/activity |
Lower CSF 5-HIAA concentrations | S | - - - /+ + | Lower central 5-HT turnover/activity |
Higher platelet 5-HT2 receptor binding | S | + + | Indicative of up-regulated (central?) 5-HT2 receptors |
Higher postmortem brain 5-HT2 receptor binding |
S | - /+ + + | Up-regulated central 5-HT2 receptors (prefrontal cortex) |
Lower 5-HT2 antagonist-induced slow wave sleep |
S | + | Up-regulated central 5-HT2 receptors |
Lower postmortem brain 5-HT1A receptor binding |
S | - / + + | Down-regulated central 5-HT1A receptors/hippocampus |
Lower TRP-induced prolactin | S | - / + + + | Indicative of lower central presynaptic 5-HT activity or postsynaptic receptor responsivity |
Higher TRP-induced cortisol | S | - / + + | Indicative of up-regulated central 5-HT2 receptors |
Higher 5-HTP-induced cortisol | S | - / + + + | Indicative of up-regulated central 5-HT2 receptors |
Lower fenfluramine-induced prolactin | S | - / + + + | Indicative of lower central presynaptic 5-HT activity or postsynaptic receptor responsivity |
Lower clomipramine-induced prolactin | S | + + | Indicative of lower central presynaptic 5-HT activity or postsynaptic receptor responsivity |
Lower buspirone-induced cortisol/production | - | ||
Lower ipsapirone-induced cortisol | S | + + | Indicative of downregulated central 5-HT1A receptors |
Higher TRP, fenfluramine, or clomipramine-induced prolactin responses to ADTc | S | + + | ADT increase brain 5-HT activity (pre- or postsynaptic) |
Lower 5-HTP-induced cortisol to ADT | I | 0 | ADT may desensitize 5-HT2 receptors |
published 2000