Early Onset of Selective Serotonin Reuptake Inhibitor Antidepressant Action

Taylor, Matthew; Freemantle, Nick; Geddes, John; Bhagwagar, Zubin

doi:10.1001/archpsyc.63.11.1217

Cited by 331 publications

(215 citation statements)

References 55 publications

Supporting

Mentioning

195

Contrasting

Unclassified

Order By: Relevance

“…It was suggested that the ability of acute drug administration to alleviate behavioral depression in the swim test might not mimic treatments given to human depressives, which normally take at least a week to produce noticeably results (Taylor et al, 2006). To strengthen the face validity of the swim test, Detke et al (1997) administered low doses (1-5 mg/kg, s.c.) of fluoxetine daily for 2 weeks.…”

Section: Discussionmentioning

confidence: 99%

Fluoxetine Alleviates Behavioral Depression while Decreasing Acetylcholine Release in the Nucleus Accumbens Shell

Chau

Rada

Kim

et al. 2011

Neuropsychopharmacol

View full text Add to dashboard Cite

Selective serotonin reuptake inhibitors, such as fluoxetine, have demonstrated the ability to alleviate behavioral depression in the forced swim test; however, the sites and mechanisms of their actions remain to be further elucidated. Previous studies have suggested that behavioral depression in the swim test is mediated in part by acetylcholine (ACh) stimulating the cholinergic M1 receptors in the nucleus accumbens (NAc) shell. The current study tested whether acute, local, and chronic, subcutaneous fluoxetine treatments increase escape motivation during the swim test while simultaneously lowering extracellular ACh in the NAc shell. Experiment 1: Fluoxetine (1.0 mM) infused unilaterally in the NAc shell for 40 min reduced extracellular ACh while simultaneously increasing swimming time. Experiment 2: Fluoxetine (0.2, 0.5, and 0.75 mM) infused bilaterally in the NAc shell on day 3 dose-dependently decreased immobility and increased the total escape attempts (swimming and climbing) compared with Ringer given on day 2. Experiment 3: Fluoxetine (0.5 mM) infused bilaterally in the NAc for 40 min did not affect activities in an open field. Experiment 4: Chronic systemic fluoxetine treatment decreased immobility scores and increased total escape attempt scores compared with control saline treatment. In all, 14 days after the initial swim test, basal extracellular ACh in the shell was still elevated in the saline-treated group, but not in the fluoxetine-treated group. In summary, these data suggest that one of the potential mechanisms by which fluoxetine alleviates behavioral depression in the forced swim test may be to suppress cholinergic activities in the NAc shell.

show abstract

Section: Discussionmentioning

confidence: 99%

Fluoxetine Alleviates Behavioral Depression while Decreasing Acetylcholine Release in the Nucleus Accumbens Shell

Chau

Rada

Kim

et al. 2011

Neuropsychopharmacol

View full text Add to dashboard Cite

show abstract

“…It is widely held that significant antidepressant treatment effects are not reliably demonstrated until after several weeks of treatment. However, the results from a recent meta-analysis 16 (which has the advantage of pooling results from a large number of well designed placebo controlled studies) suggest that antidepressant treatment is associated with significant symptomatic improvement by the end of the first week of use. It is tempting to speculate that the rapid, antidepressant-induced, positive bias reported here, and in our earlier behavioural 4,5 and fMRI studies 15 is an important component of early antidepressant action.…”

Section: Discussionmentioning

confidence: 99%

“…Recent metaanalysis suggests that positive effects of antidepressants on clinical symptoms can be seen as early as one week after treatment initiation. 16 The current study, therefore, aimed to investigate the effects of shortterm reboxetine (7 days) upon emotional categorization and successful recognition of emotional items processed in a self-referential manner using a rapid event-related fMRI design. Based on the findings from our earlier behavioural studies 4,5 and fMRI studies 14 we wished to test the following specific predictions:…”

Section: Introductionmentioning

confidence: 99%

The effects of reboxetine on emotional processing in healthy volunteers: an fMRI study

et al. 2007

View full text Add to dashboard Cite

Recent neuropsychological studies in healthy volunteers suggest that antidepressants enhance the processing of positive emotional information. However, the neural substrates underpinning these changes have not been fully elucidated. The current study, therefore, used functional magnetic resonance imaging (fMRI) to map brain systems activated during successful categorization and subsequent recognition of self-referent positive and negative personality characteristics in healthy volunteers following short-term (7 days) repeated administration of the selective noradrenergic reuptake inhibitor reboxetine. Twenty-four healthy volunteers were randomly assigned to 7-day double-blind intervention with reboxetine or placebo. On day 7, neural responses during the categorization and subsequent recognition of positive and negative characteristics were assessed using fMRI. Questionnaires monitoring mood, hostility and anxiety were given before and during this intervention. During categorization, reboxetine was associated with greater activation to positive words, relative to negative words, in left precuneus and right inferior frontal gyrus. By contrast, at subsequent recognition reboxetine was associated with reduced response to positive words, relative to negative words, in left precuneus, anterior cingulate and medial frontal gyrus. These changes in the neural processing of positive and negative words occurred in the absence of significant differences in ratings of mood and anxiety. Such adaptations in the neural processing of emotional information support the hypothesis that antidepressants have early effects on emotional processing in a manner which would be expected to reverse negative biases in depression.

show abstract

“…Indeed, the improvement seen over this time was greater than in any subsequent week though the overall difference between placebo and active drug accumulated as time went by [13]. The picture therefore is of a steady linear improvement in depressive symptoms from the very start of treatment which increased over time.…”

Section: (C) Neuroadaptive Effects Of Ssrismentioning

confidence: 91%

‘It's the way that you look at it’—a cognitive neuropsychological account of SSRI action in depression

Harmer

Cowen

2013

Phil. Trans. R. Soc. B

145

126

View full text Add to dashboard Cite

The fact that selective serotonin reuptake inhibitors (SSRIs) have antidepressant effects in some patients supports the notion that serotonin plays a role in the mode of action of antidepressant drugs. However, neither the way in which serotonin may alleviate depressed mood nor the reason why several weeks needs to elapse before the full antidepressant effect of treatment is expressed is known. Here, we propose a neuropsychological theory of SSRI antidepressant action based on the ability of SSRIs to produce positive biases in the processing of emotional information. Both behavioural and neuroimaging studies show that SSRI administration produces positive biases in attention, appraisal and memory from the earliest stages of treatment, well before the time that clinical improvement in mood becomes apparent. We suggest that the delay in the clinical effect of SSRIs can be explained by the time needed for this positive bias in implicit emotional processing to become apparent at a subjective, conscious level. This process is likely to involve the re-learning of emotional associations in a new, more positive emotional environment. This suggests intriguing links between the effect of SSRIs to promote synaptic plasticity and neurogenesis, and their ability to remediate negative emotional biases in depressed patients.

show abstract

Early Onset of Selective Serotonin Reuptake Inhibitor Antidepressant Action

Abstract: Treatment with SSRIs is associated with symptomatic improvement in depression by the end of the first week of use, and the improvement continues at a decreasing rate for at least 6 weeks.

Cited by 331 publications

References 55 publications

Fluoxetine Alleviates Behavioral Depression while Decreasing Acetylcholine Release in the Nucleus Accumbens Shell

Fluoxetine Alleviates Behavioral Depression while Decreasing Acetylcholine Release in the Nucleus Accumbens Shell

The effects of reboxetine on emotional processing in healthy volunteers: an fMRI study

‘It's the way that you look at it’—a cognitive neuropsychological account of SSRI action in depression

Contact Info

Product

Resources

About