Posted by SLS on September 21, 2006, at 12:44:34
In reply to Re: Nicotine works :s, posted by linkadge on September 21, 2006, at 9:28:32
I wish the authors of the following study took their jobs more seriously. They had a good idea - to study nicotine as an antidepressant - but made the results worthless. The results were that nicotine was no better than placebo after chronic administration after 4 weeks. I happen to believe that this would be the outcome in a properly-designed study, but this one has some glaring weaknesses that make it impossible to draw any conclusions.
1. Only 11 subjects?2. The CES-D rating scale does not consider a score of 10 to be depressed. The scale ranges 0-60, with higher scores indicating more severe depression. This study allowed people in with scores as low as 10. It is possible that only mild depressions are being studied here.
3. The amount of nicotine given did not remain constant throughout the trial. No reason was given for this. It was identified as a confounding variable in interpreting results.
4. The abstract declined to report the results at day 21.
* It is interesting to note that they did not report any improvement in mood from nicotine when given acutely.I believe that nicotine can produce improvements in mood from acute and sub-chronic administration (8 days), but not from chronic administration. I just don't believe that its effects can be sustained. I don't think it is a matter of MAOI inhibition protecting DA supply. I don't think there is the type of second-messenger induced changes in gene expression occurring with nicotine that is probably necessary in producing a true antidepressant response. I think it takes a minimum of 2 weeks for this to occur, not the 1 week (8 days) seen here. The reason the nicotine pooped-out was probably because of receptor reregulation, not because of neurotransmitter depletion or a drop in nicotine administration.
I think this study got the right answers, despite its shortcomings.
- Scott
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Psychopharmacology (Berl). 2006 Sep 15; [Epub ahead of print] Related Articles, Links
Click here to read
Transdermal nicotine attenuates depression symptoms in nonsmokers: a double-blind, placebo-controlled trial.McClernon FJ, Hiott FB, Westman EC, Rose JE, Levin ED.
Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA, mccle011@mc.duke.edu.
RATIONALE: Despite established links between nicotine dependence and depression, little research has examined the effects of nicotine on depression symptoms. OBJECTIVE: This study evaluated the acute and chronic effects of transdermal nicotine in nonsmokers with baseline depression symptoms during a 4-week, double-blind, placebo-controlled trial. METHODS: Nonsmokers with scores >/=10 on the Center for Epidemiological Studies Depression scale (CES-D) were recruited from the community. Mood and cognitive performance were measured at baseline (day 0) and at 1, 8, 21, and 28 days. Participants were randomly assigned to wear a placebo or nicotine patch for 4 weeks (3.5 mg/day during weeks 1 and 4; 7 mg/day during weeks 2 and 3). The final sample consisted of 11 nonsmokers with a mean baseline CES-D score of 27.36 (SD=10.53). RESULTS: Salivary nicotine levels indicated the majority of participants were compliant with treatment. Acute nicotine did not alter mood. After adjusting for baseline values, chronic nicotine resulted in a significant decline in CES-D scores at day 8 (3.5 mg/day), but returned to placebo levels by the last visit. This return to baseline levels was coincident with a decrease in nicotine administration from 7 to 3.5 mg/day. A similar trend for improved response inhibition as measured by the Conners Continuous Performance Task was also observed. Reported side effects were infrequent and minimal. CONCLUSION: These findings suggest a role for nicotinic receptor systems in the pathophysiology of depression and that nicotinic compounds should be evaluated for treating depression symptoms.
PMID: 16977477 [PubMed - as supplied by publisher]
poster:SLS
thread:687688
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