Nicotine & Mental Health

[Change]

Quality of life and risk of psychiatric disorders among regular users of alcohol, nicotine, and cannabis: An analysis of the National Epidemiological Survey on Alcohol and Related Conditions (NESARC).

Research is limited on the effects of regular substance use on mental health-related outcomes. We used a large nationally representative survey to examine current and future quality of life and risk of psychiatric disorders among past-year regular (weekly) users of alcohol, nicotine, and cannabis. Data on psychiatric disorders and quality of life from two waves (Wave 1 N = 43,093, Wave 2 N = 34,653) of the National Epidemiological Survey on Alcohol and Related Conditions (NESARC) were used to test study aims. In cross-sectional analyses, regular nicotine and cannabis use were associated with higher rates of psychiatric disorder, though regular alcohol use was associated with lower rates of disorders. Prospective analyses found that regular nicotine use predicted onset of anxiety, depressive, and bipolar disorders. Regular alcohol use predicted lower risk of these disorders. Regular cannabis use uniquely predicted the development of bipolar disorder, panic disorder with agoraphobia, and social phobia. Lastly, regular alcohol use predicted improvements in physical and mental health-related quality of life, whereas nicotine predicted deterioration in these outcomes. Regular cannabis use predicted declines in mental, but not physical health. These data add to the literature on the relations between substance use and mental and physical health and suggest increased risk of mental health problems among regular nicotine and cannabis users and better mental and physical health among regular alcohol users. Examination of mechanisms underlying these relationships is needed.

http://www.ncbi.nlm.nih.gov/pubmed/26022838

Reading this really confused me, as i regularly ingest nicotine to try and help calm my nerves

[Change]

Nicotine Modulation of Fear Memories and Anxiety: Implications for Learning and Anxiety Disorders.

Anxiety disorders are a group of crippling mental diseases affecting millions of Americans with a 30% lifetime prevalence and costs associated with healthcare of $42.3 billion. While anxiety disorders show high levels of co-morbidity with smoking (45.3% vs. 22.5% in healthy individuals), anxietydisorders are also more common among the smoking population (22% vs. 11.1% in the non-smoking population). Moreover, there is clear evidence that smoking modulates symptom severity in patients with anxiety disorders. In order to better understand this relationship, several animal paradigms are used to model several key symptoms of anxiety disorders; these include fear conditioning and measures of anxiety. Studies clearly demonstrate that nicotine mediates acquisition and extinction of fear as well as anxiety through the modulation of specific subtypes of nicotinic acetylcholine receptors (nAChRs) in brain regions involved in emotion processing such as the hippocampus. However, the direction of nicotine's effects on these behaviors is determined by several factors that include the length of administration, hippocampus-dependency of the fear learning task, and source ofanxiety (novelty-driven vs. social anxiety). Overall, the studies reviewed here suggest that nicotine alters behaviors related to fear and anxiety and thatnicotine contributes to the development, maintenance, and reoccurrence of anxiety disorders.

http://www.ncbi.nlm.nih.gov/pubmed/26231942

[Anodyne]

I might be misunderstanding some stuff, but it all kinda makes sense to me. If nicotine is enhancing certain types of learning as this^[1] and many other articles suggest, then it makes sense that this would have knock-on effects. So if you learn that imbibing nicotine feels nice or learn that a certain situation makes you feel nervous, then those associations will be stronger with nicotine, which would then contribute to addiction & increased (contextual) anxiety eventually. There's also the effects of withdrawal which seem to increase anxiety levels in a few different ways^[1]. When you learn to associate a particular event, like being out in public say, with a feeling of fear/nervousness, you would normally forget about this sensation to some extent between your trips outside ("fear extinction") - apparently one effect of nicotine^[2] is to reduce the extent of this forgetting - you remember your fear better & so the association & anxiety are greater.

Reading this really confused me, as i regularly ingest nicotine to try and help calm my nerves

Keep in mind that they aren't talking about the immediate effects of nicotine on anxiety (especially if you are already dependent). In fact, they're not talking about nicotine effects at all, rather the correlation between long-term nicotine use & mental health. There is nothing to say that this link is causal. There's a long-standing theory that people with certain mental disorders like schizophrenia are actually self-medicating with nicotine in an attempt to reduce their symptoms^[3,4] (&/or the side-effects of their meds!), although there are some problems with the theory (critique here). Not surprisingly, the similar correlation between marijuana smoking & schizophrenia is seen as proof that pot causes mental illness.

1. Modulation of hippocampus-dependent learning and synaptic plasticity by nicotine

"In summary, the various effects of nicotine on different LTP stimulation protocols in different areas of the hippocampus suggest a number of possible mechanisms by which nicotine may act to enhance learning and memory processes. Enhancement of HFS LTP in the PP-DG pathway by nicotine suggests that connections normally formed during learning may be stronger when formed in the presence of nicotine."

2. Prior chronic nicotine impairs cued fear extinction but enhances contextual fear conditioning in rats:

"In the contextual task, the same nicotine treatment schedule did not affect the acquisition of fear response or the within- and between-session fear extinction, but enhanced the retention of fear conditioning. This prior chronic nicotine-induced deficit in cued fear extinction and/or enhanced fear to context may be one of the critical components that contribute to the progression from nicotine dependence to an anxiety disorder."

3. Why do schizophrenic patients smoke?

Abstract

Patients suffering from schizophrenia are known to show an increased prevalence of nicotine addiction. The aim of this paper is to elucidate the relationship between schizophrenia and (chronic) use of nicotine. Nicotine seems to improve cognitive functions critically affected in schizophrenia, in particular sustained attention, focused attention, working memory, short-term memory, and recognition memory. Furthermore, several studies using evoked potentials (P50 paradigm) and prepulse inhibition of the acoustic startle reflex suggest that deficient preattentive information processing, a core feature of schizophrenia illness, is improved following treatment with nicotine. Smoking can also improve extrapyramidal secondary effects of antipsychotic medication and it induces cytochrome P4501A2, an enzyme system involved in the metabolism of several antipsychotics. There is substantial evidence that nicotine could be used by patients with schizophrenia as a "self-medication" to improve deficits in attention, cognition, and information processing and to reduce side effects of antipsychotic medication. Possible pharmacotherapeutic approaches for the regulation of abnormal neurotransmission at nicotinic acetylcholine receptors are discussed.

4. Nicotine effects on brain function and functional connectivity in schizophrenia.

Abstract

BACKGROUND:

Nicotine in tobacco smoke can improve functioning in multiple cognitive domains. High rates of smoking among schizophrenic patients may reflect an effort to remediate cognitive dysfunction. Our primary aim was to determine whether nicotine improves cognitive function by facilitating activation of brain regions mediating task performance or by facilitating functional connectivity.

RESULTS:

During the most difficult task condition, nicotine improved performance of schizophrenic subjects and worsened performance of control subjects.

CONCLUSIONS:
In tasks that tax working memory and selective attention, nicotine may improve performance in schizophrenia

[Strontium Dawg]

http://www.dailymail.co.uk/health/article-3185189/Taking-cannabis-teens-NOT-linked-depression-lung-cancer-asthma-later-life-study-reveals.html#ixzz3hs6vF7ty

[Strontium Dawg]

Sorry, I should note that I posted the article above in response to anodyne's comment regarding links between cannabis use and mental disorders such as schizophrenia. I make no claims as to the veracity of the research or the possible cherry picking of outcomes by the writer of the article.