February Newsletter
In This Issue
Move To Think Better
Sleep Loss is a Pain
It's Just Weed...
A Better Model of Medical Care
Old-fashioned medicine with 21st Century convenience and technology
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I hope this newsletter finds you and your family well. I have had a busy month of travel. I started out in Park City for the FIS Freeski and Snowboard World Championships. It was great working with the best skiers and riders in the world. Good to see the US get our share of hardware. And of course the Brewers started spring training. The new facility in Phoenix is everything you have read about and more. All the planning and hard work really paid off. It is truly impressive and our team now has the best facility in the league to develop our next generation of stars. Another step toward bringing a championship to Milwaukee! 

One of our major concerns with aging is cognition, how well we think. I often get questions regarding various supplements or medications purported to boost our thinking. But there is something that is free and available to us all which has been shown to improve our executive (highest level) thinking and is more effective as we age. Interested? Check out the first article. 

We have all had a bad night sleep. Perhaps we noticed that everything just felt worse the next day. Why is this? How does sleep affect our pain levels, does everything hurt more when we lose sleep? The second article explores this interesting topic. 

Cannabis has been legalized for recreational use in 10 states and Washington, DC. While the law bans use by those under 21, we know that there is use in the younger age groups. What are the effects of use of this substance on the developing brain, and what effects are seen later in life? The third article explores this topic. 

Another  reminder to update our email contacts if you haven't done so already. You can reach the office at office@drniedfeldt.com. I can be reached directly at mark@drniedfeldt.com and Colleen can be reached directly at colleen@drniedfeldt.com. Our phone number and fax are unchanged. 

Click on the links the the left to check out our  web site .
Move to Think Better
Exercise boosts cognition
Regular aerobic exercise may improve cognition, especially high level functions in adults. A new study published in the journal Neurology enrolled 132 people with below average aerobic capacity and divided them into two groups. Both groups performed four weekly training sessions for 6 months. One group performed aerobic activities such as walking on a treadmill, stationary cycling or using an elliptical machine. The other group did stretching exercises to promote flexibility. Each training session included 10-15 minutes of warm-up/cool-down and 30-40 minutes of exercise. Cognitive function including executive function, memory, processing speed, language and attention were evaluated. Executive function includes several skills such as paying attention, organizing, planning and prioritizing tasks, staying focused, working memory, keeping track of what you are doing, impulse and emotional control. Additionally, everyday function and body mass index (BMI) was evaluated. All participants underwent MRI scanning to determine cortical thickness. Overall, aerobic exercise improved cognition and the improvement was more notable as people aged with 60 year-olds showing twice as much improvement than 40 year-olds. MRI scans showed cortical thickening in the aerobic exercise group in the frontal cortex (where decisions are made). 
  • Objective: To determine efficacy of aerobic exercise for cognitive function in younger healthy adults.
  • Methods In a randomized, parallel-group, observer-masked, community-based clinical trial, 132 cognitively normal individuals aged 20-67 with below median aerobic capacity were randomly assigned to one of two 6-month, 4-times-weekly conditions: aerobic exercise and stretching/toning. Efficacy measures included aerobic capacity; cognitive function in several domains (executive function, episodic memory, processing speed, language, and attention), everyday function, body mass index (BMI), and cortical thickness.
  • Results Aerobic capacity increased significantly (β = 2.718; p = 0.003), and BMI decreased significantly (β = −0.596; p = 0.013) in the aerobic exercise but not in the stretching/toning condition. Executive function improved significantly in the aerobic exercise condition; this effect was moderated by age (β = 0.018 SD/y; p = 0.028). At age 40, the executive function measure increased by 0.228 SD (95% confidence interval [CI] 0.007-0.448), and by 0.596 SD (95% CI 0.219-0.973) at age 60. Cortical thickness increased significantly in the aerobic exercise group in a left frontal region and did not interact with age. Controlling for age and baseline performance, individuals with at least one APOE ε4 allele showed less improvement in executive function with aerobic exercise (β = 0.5129, 95% CI 0.0381-0.988; p = 0.0346).
  • Conclusions This randomized clinical trial demonstrates the efficacy of aerobic exercise for cognition in adults age 20-67. The effect of aerobic exercise on executive function was more pronounced as age increased, suggesting that it may mitigate age-related declines. Increased cortical thickness suggests that aerobic exercise contributes to brain health in individuals as young as age 20.

It seems like every day I have a patient or two who asks me about brain function with aging. Some of my patients are concerned about dementia every time they misplace their car keys or walk into a room and can't remember why they are there. As we age, brain health and especially brain function are major concerns and people are always asking me what they can do. We have looked at the effects of diet on dementia in previous newsletters. This study focuses on exercise. The subjects exercised 4x/week for 30-40 minutes on a treadmill, bike or elliptical. This was moderate exercise as they exercised at 55-65% of their maximal heart rate (HR) initially, increasing to 75% of maximal HR as they progressed. A control group did stretching and toning only. The group that did the aerobic exercise had improvements in aerobic capacity which correlated with improvement in cognitive functioning. Interestingly, these benefits were seen in all ages down to age 20 with most dramatic improvement at age 60. It would be interesting to look at this study in light of insulin resistance (which unfortunately wasn't tested). Perhaps the exercise improved this which could account for some of the improvements seen. The take home message is that it is never to young to start exercising. Your brain will thank you!

Sleep Loss is a Pain
Correlation between loss of sleep and perception of pain
sleeping man

We have all probably had the experience of waking up after a bad night of sleep and feeling more aches and pains all over our body, or had the experience of pain keeping us awake. Does this lack of sleep affect our perception of pain and actually make our pain worse? This study, published in The Journal of Neuroscience looked at this question. The authors found underlying brain and behavioral mechanisms which explain this phenomenon. Sleep deprivation enhances our pain responsiveness in our brain's cortex and blunt activity in other regions that modulate our pain processing. As a result, we are primed to experience pain when we are sleep deprived and a bad night of sleep will results in higher perceived levels of pain.  


  • Sleep loss increases the experience of pain. However, the brain mechanisms underlying altered pain processing following sleep deprivation are unknown. Moreover, it remains unclear whether ecologically modest night-to-night changes in sleep, within an individual, confer consequential day-to-day changes in experienced pain. Here, we demonstrate that acute sleep-deprivation amplifies pain reactivity within human (male and female) primary somatosensory cortex yet blunts pain-reactivity in higher-order valuation and decision-making regions of the striatum and insula cortex. Consistent with this altered neural signature, we further show that sleep deprivation expands the temperature range for classifying a stimulus as painful, specifically through a lowering of pain thresholds. Moreover, the degree of amplified reactivity within somatosensory cortex following sleep deprivation significantly predicts this expansion of experienced pain across individuals. Finally, outside of the laboratory setting, we similarly show that even modest nightly changes in sleep quality (increases and decreases) within an individual determine consequential day-to-day changes in experienced pain (decreases and increases, respectively). Together, these data provide a central brain framework underlying the impact of sleep loss on pain, and furthermore, establish that the association between sleep and pain is expressed in a night-to-day, bidirectional relationship within a sample of the general population. More broadly, our findings highlight sleep as a novel therapeutic target for pain management within and outside the clinic, including circumstances where sleep is frequently short yet pain is abundant (e.g. the hospital setting).
Does a bad night of sleep make things more painful? The answer appears to be yes. In this study, people were given a standardized pain exposure. They were then deprived of sleep and were given the same test. They felt more pain at lower levels of heat (the pain stimulus) when sleep deprived, their pain threshold was lowered. Additionally, functional MRI scans were performed and showed that the areas of the brain correlated with pain were more responsive after sleep loss so lower levels of pain were perceived as very painful. The researchers found that even one night of poor sleep lowered the pain threshold. The mechanism involves two things, increased sensitivity in the pain response ares of the brain and blocking of the receptors in our bodies that inhibit or block pain responses. The results is a lack of filtering of the pain response to our brain so we experience the full affects of the painful stimulus. This really has important  implications on how to manage pain. Getting good sleep should be a priority. Anyone who has spent the night in a hospital knows that it is a terrible place to get a good night of sleep. We should work to minimize anything that disturbs patient's sleep in the hospital. They need it to recover but it looks to also be important for their pain levels. 
It's Just Weed...
Cannabis use in adolescence and risk of depression, anxiety and suicidality
Cannabis is the most commonly used drug by adolescents with up to a fifth of adolescents using it and 7% of high school seniors report near daily use. Ten states and Washington, DC have now legalized marijuana for recreational use for adults over 21. Although laws prohibit use prior to 21, as we know with alcohol, it is available to younger teens. What are the effects of cannabis on the still developing brain? This systematic review and meta-analysis looked at this question in regards to depression, anxiety and suicidal behavior in 23,000 subjects between the ages of 18-35. They found those who used cannabis under age 18 had a 37% higher risk of depression and 3.5-fold higher risk of attempting suicide than non-users. 

  • Importance  Cannabis is the most commonly used drug of abuse by adolescents in the world. While the impact of adolescent cannabis use on the development of psychosis has been investigated in depth, little is known about the impact of cannabis use on mood and suicidality in young adulthood.
  • Objective  To provide a summary estimate of the extent to which cannabis use during adolescence is associated with the risk of developing subsequent major depression, anxiety, and suicidal behavior.
  • Data Sources  Medline, Embase, CINAHL, PsycInfo, and Proquest Dissertations and Theses were searched from inception to January 2017.
  • Study Selection  Longitudinal and prospective studies, assessing cannabis use in adolescents younger than 18 years (at least 1 assessment point) and then ascertaining development of depression in young adulthood (age 18 to 32 years) were selected, and odds ratios (OR) adjusted for the presence of baseline depression and/or anxiety and/or suicidality were extracted.
  • Data Extraction and Synthesis  Study quality was assessed using the Research Triangle Institute item bank on risk of bias and precision of observational studies. Two reviewers conducted all review stages independently. Selected data were pooled using random-effects meta-analysis.
  • Main Outcomes and Measures  The studies assessing cannabis use and depression at different points from adolescence to young adulthood and reporting the corresponding OR were included. In the studies selected, depression was diagnosed according to the third or fourth editions of Diagnostic and Statistical Manual of Mental Disorders or by using scales with predetermined cutoff points.
  • Results  After screening 3,142 articles, 269 articles were selected for full-text review, 35 were selected for further review, and 11 studies comprising 23,317 individuals were included in the quantitative analysis. The OR of developing depression for cannabis users in young adulthood compared with nonusers was 1.37 (95%CI, 1.16-1.62; I2 = 0%). The pooled OR for anxiety was not statistically significant: 1.18 (95% CI, 0.84-1.67; I = 42%). The pooled OR for suicidal ideation was 1.50 (95% CI, 1.11-2.03; I2 = 0%), and for suicidal attempt was 3.46 (95% CI, 1.53-7.84, I2 = 61.3%).
  • Conclusions and Relevance  Although individual-level risk remains moderate to low and results from this study should be confirmed in future adequately powered prospective studies, the high prevalence of adolescents consuming cannabis generates a large number of young people who could develop depression and suicidality attributable to cannabis. This is an important public health problem and concern, which should be properly addressed by health care policy.

Marijuana  use has become more accepted over the past few years both in a medicinal setting and recreationally. Ten states have now legalized recreational cannabis and use is more acceptable than it was a few years ago. The percentage of teens using cannabis had be decreasing for several years but is now increasing again. The cannabis available today is more potent that what was available years ago. This study found a significantly increased risk of depression and greatly increased risk of suicide in teen cannabis users. While we can't prove causation and there is always the question of self-medication, this should raise some red flags for us as a society. I do believe that there are legitimate medical uses of cannabis/CBD/hemp. But we need to be aware of what use and especially heavy use (7% of high school seniors use nearly daily) means and the risks that are involved. At this point we don't understand all the effects on the developing brain and like the use of all mood altering substances (including prescription medications), we need to think ahead and take these effects into consideration. We also need to monitor heavy users as they progress into young adulthood as they are at higher risk of depression and suicide. 

Thank you for taking the time to read through this newsletter. I hope you have found this information useful as we work together to optimize your health. Feel free to pass this on to anyone you think would benefit from this information. 

You can find previous newsletters archived on my website here


As always, if you have questions about anything in this newsletter or have topics you would like me to address, please feel free to contact me by email , phone, or just stop by! 

To Your Good Health,
Mark Niedfeldt, M.D.