Prairie Voles Again!
I do hope that we are all properly appreciative of the scientific contribution of these cute little creatures. I mentioned them in one of my Valentine’s Day posts, but you will find a picture and an accompanying story here.
Thomas Insel’s group at the National Institute of Mental Heath in Bethesda have spent years working on pair formation and partner preference in these little fur balls.
It seems that pouring dopamine into a region of their brains known as the nucleus accumbens makes male prairie voles seek out girlfriends. There are at least seven major subgroups of dopamine receptors. But in these little creatures D2 receptors are involved in approach behavior that is associated with the formation of a pair-bond, and D1 receptors maintain the bond. While forming a relationship the little vole’s brain actually changes.
I am always a bit worried about trying to read too much into these experiments, because human behavior really is a great deal more complicated. But I have a couple of thoughts:
1. Dopamine receptors are proteins, so they are products of genes that get switched on by the formation of a relationship. Might some people have a genetic reason for having difficulties in relationship formation, and how would that play with environmental factors? You may well know some people who seem cold and uninterested in relationships, and indeed, there are some personality disorders in which people have chronic difficulties in forming relationships. Yet certain types of psychological therapy can help them.
2. Some antipsychotic medications block D2 receptors. Is that a further explanation for the relationship difficulties of some people receiving these medicines?
3. I think that we should thank the Prairie Vole Kingdom for their help…..
Technorati tags: relationships, dopamine, love, science of love
Sleep and Mood
The interaction between sleep and mood is fascinating, complex and supremely practical.
I have received a couple of queries and comments. Let me start with one from a physician:
“I have a question about sleep disorders. My patients seem to suffer from this even after their depression is better.”
This is an extremely interesting issue.
Every healthcare student has been taught about the sleep disturbances that may occur in association with mood disorders. The classic problems in depression are early morning wakening, difficulty in getting off to sleep and sometimes waking in the early hours. Some others will sleep for very long periods, and there has been speculation that this may be a form of hibernation behavior. People with abnormally elevated mood can often stay awake for days at a time. There is also the well-known problem of seasonal affective disorder, in which the long winter nights can cause depression. Fortunately the depression is often relieved by the use of a light box.
Many experts now consider that the disturbances of sleep are often the primary problem, which then cause depressed or elevated mood. This is actually not a new idea: one of the old fashioned treatments for depression was sleep deprivation and many of us who have worked all night have experienced the mildly manic symptoms of sleep deprivation. On early morning rounds at the hospital I commented that it was easy to tell if some of the residents had been working all night, even before they presented their reports. The giggling, high energy and disturbances in thought patterns were not at all what one sees when someone is tired.
It is not just the sleep deprivation, but also light. It is well known that people suffering with bipolar disorder are more likely to get manic episode in the spring and early summer, as the amount of ambient light increases. It is the converse of the seasonal affective disorder problem.
So what often happens is that antidepressant medications do indeed help with the depressed mood, but the underlying sleep problem takes much longer to correct itself. This is also one of the reasons why people who have seen their mood improve on treatment still have cognitive problems that can go on for months after the mood symptoms have been corrected. It is probably a combination of sleep deprivation and also the impact of corticosteroids that can rise in some sufferers causing transient damage to some key regions of the brain.
It would be nice if we could modulate people’s sleep/wake cycles and thereby treat the mood problems directly, but at the moment, despite the enormous advances in pharmacological treatments of sleep problems, we are still not able to do that reliably.
Technorati tags: Sleep, Mood, bipolar disorder, Depression,
Nutrition and Mental Health
Our brains are delicate organs sustained by a fine balance of fatty and amino acids, minerals and vitamins.
Virtually everyone of us has had the experience of a mood change if we become hypoglycemic, or sleepiness after eating chocolate or tryptophan-containing turkey. The scientific literature is full of reports about the impact of different foods and combinations of food on mood, alertness and cognition. Some of the links are not obvious. I was brought up with the old wives tale that children become sleepy after lunch or dinner because blood was being diverted to the intestines. Not so: sugary and fatty foods cause sleepiness by altering the secretion of insulin by the pancreas, which in turn effects the uptake of key amino acids in the brain, which in turn impact the synthesis of some neurotransmitters.
There has also been another yet more serious issue that has been turning up in the literature for decades, and that is the inter-relationships between diet, nutrition and mental illness. Epidemiological studies have found a clear relationship between the consumption of fish and the incidence and prevalence rates around the world: high fish consuming countries tend to have less depression. This relationship has held up in studies around the globe, so it is unlikely that it is simply that people living by the ocean in warm sunny countries are less likely to become depressed. These observations were part of what led Dr Andrew Stoll at Harvard to first study the impact of fish oils, containing omega-3 fatty acids, on mood. The results of the early studies were more impressive than the later ones, but the fact remains that fish oils have been helpful in a proportion of patients. The experimental work continues, in order to try and find the best and most effective mixture of fatty acids.
There is a theoretical reason why this might be: fish oils can change the characteristics of the membranes of many cells, including those in the brain, and thereby influence the firing and response of some neurotransmitters important in the maintenance of mood.
There have been recent reports from well-conducted studies of the impact on nutritional supplementation on reducing violence in prisons and that work is also continuing. The BBC has picked up on an eagerly awaited report from the Mental Health Foundation and Sustain. Called Feeding Minds this report by mental health advocates and food campaigners is ambitious and presents a good summary of the current state of the evidence, though its findings are sure to be controversial.
The report points out that changes in the composition of Western diets with the proliferation of industrialized farming and pesticide use and the depletion of some essential nutrients in the soil has coincided with a continuing increase in the incidence and prevalence rates of mental illness. It is always difficult to prove causality with research like this, since there have been many other social changes which could equally account for a rise in the rates of mental illness, to say nothing of ever-changing diagnostic criteria, that have sometimes labeled people with mental illness who would at one time have been described just as “different” or “eccentric” or “difficult.” But it is also fair to say that few people doubt the link between cigarette smoking and lung cancer, but to prove causality is bound to be difficult. This is very different from the situation with infectious diseases. Here we have had a set of four criteria which we can use to show whether or not an infectious organism is the cause of a disease. Known as Koch’s Postulates, which have guided us for 122 years and have so far been proven time and time again. These postulates have been modified over the years, yet still formed the basis of the work which lead to the 2005 Nobel Prize in Physiology or Medicine.
Sad to say, things are not so clear when looking at nutrition and mental illness. But let’s look at a few key items in the report:
1. Depression: I have mentioned this one already, and the report also emphasizes the link between depression and low consumption of fish that are high in omega-3 fatty acids
2. Schizophrenia: A link between some fatty acids and schizophrenia was first proposed by the late Dr. David Horrobin in the 1970s, and increasing epidemiological evidence has shown that sufferers have lower levels of polyunsaturated fatty acids (PUFA). There have been many studies which have attempted to modulate them to treat the disease, with some measure of success. Just this month there is a report in the British Journal of Psychiatry on the adjunctive use of PUFAs in the closely related condition of bipolar disorder.
3. Alzheimer’s disease: Some studies have suggested that a high consumption of vegetables, particularly those containing folate, can protect against or slow the progression of this brain disorder.
4. Attention deficit and/or hyperactivity disorder: Research shown that some children with these disorders are low in iron and fatty acids, though it is not so clear whether treatment with these agents will help these children.
In my book Healing, Meaning and Purpose, I talk at length about the dietary and other physical changes over the last 100 years, and this report adds more. In the last 50 years, our consumption of omega-3 rich fish has fallen by two thirds, and over the same time course we have dropped our consumption of vegetables by 34%. There is something else more subtle, that I did not see in the report. In the decades after the second world war, British children were routinely given daily cod liver oil tablets rich in omega-3 fatty acids, as well as free school milk.
The report makes a point that I have before in entries here: people cannot be held totally responsible for maintaining healthy diets: some food and farming policies have lead to a situation in which people may no longer have access to healthy and nutritious foods. And that will likely cause further increases in some mental illness. And artificial supplements can rarely replace the real thing.
The evidence base associating nutrient intake and mental health is in its infancy, but it is clearly an area that needs a great deal more attention.
The recommendations in the new report are eminently sensible, and few would quibble with any of them. Before making any nutritional changes, always discuss them with your health care provider.
I would like to make a final point that I am going to amplify elsewhere:
If any health intervention is good for you, it should help more than one system of the body. So a diet that is good for mental health should also be good for the health of blood vessels, heart and skin. A diet like Nicholas Perricone’s, that aims to help skin aging, should also be good for the brain and the cardiovascular system. This is always a good way of checking to see if something is good for you and whether to adopt someone’s advice.
Technorati tags: Mentall health Nutrition Feeding Minds
Non-Pharmacological ADHD Treatments
There is a recently launched weblog, BrainWaves, being written by Zach Lynch of Neuroinsights that is becoming a “must read.” He is clearly following my policy of only writing about things that he has checked out himself. There is a terrific article on a new non-pharmacological technology for helping attention deficit disorder (ADD).
For some years I had my doubts about the diagnosis of ADD, and whether it was just a label for behaviors that some people didn’t like. But I am now convinced that it is a real problem, which if left untreated, can cause a lot of avoidable difficulties in life. Medication will not work for everyone, and the side effects can sometimes be troubling, so any new approaches are welcome. In a future entry, I shall review the research on some of the other non-pharmacological and whole-person approaches to treating ADD.
Technorati: attention deficit, attention deficit disorder, ADHD
Cannabis And Mental Illness
The debate about a possible relationship between smoking cannabis and developing mental illness – in particular schizophrenia – has been going on since the 1960s. For a long time it looked to many people as if "Cannabis psychosis" was a myth. But I’ve never been so sure. I have seen too many people who have smoked a lot of cannabis and then become psychotic.
The whole issue is now becoming clarified. We have known for years that cannabis can precipitate psychosis in people already suffering from mental illness, but over the last five years, a series of papers (article 1, article 2, article 3 –there are many more) from Scandinavia have looked at young army conscripts and found an association between the number of times that they had used cannabis and their subsequent risk of developing schizophrenia. If they had smoked more than 50 times by the age of 18, their risk of developing schizophrenia was as much as six times higher. A new study from Cambridge in England has found that repeated use in children is also associated with a 2-3 fold increased risk.
I once talked about some of this data at a meeting in Northern California and had a "vigorous" debate with some indignant colleagues who claimed that cannabis was perfectly safe. Perhaps it is in well-adjusted adults, but I’m not so sure.
And this new research raises a number of important points:
1. The cannabis that is now used by young people is much stronger than that which was on offer in the 1960s and 1970s, and is sometimes also adulterated with other substances.
2. The age at which cannabis is smoked appears to be crucial: the data suggests that it is a problem if used during the vulnerable period of brain development that occurs during early and mid-adolescence.
3. Can we say that the cannabis is having a causal role in triggering mental illness? The answer is that we can no more prove it than prove that smoking causes lung cancer. In my book Healing, Meaning and Purpose I discuss the myth of "uni-causality," the idea that there is one cause for an illness. Apart from trauma, there are extremely few examples of one illness being caused by just one deranged gene, one missing nutrient or one external toxin. There will likely be genetic, social and environmental factors that will together determine whether or not cannabis could cause psychosis.
4. Could this just be self-medication? People taking cannabis to try and treat their symptoms? That is possible, though we then have to ask why we are not seeing a similar relationship with any other substances like alcohol or Ecstasy.
5. Finally, there is some recent evidence that one of the key active ingredients in cannabis, tetrahydrocannabinol (THC), can disrupt the normal development of the microtubules that guide the development of neurons in some regions of the brain.
The moral of the story? Cannabis isn’t good for you, and it can be REALLY BAD for people during the vulnerable period of brain development.
Addendum Dec. 22, 2005: Hot off the presses! Another article on cannabis and schizophrenia.
Technorati tags: marijuana, mental illness
Addiction, Learning and Genes
Many of us have been mourning the death of George Best at the age of just 59. Arguably one of the most skillful players ever to kick a soccer ball, he finally succumbed to the slow suicide of alcohol abuse. Yet in the midst of all the opinion pieces that have tried to unravel the reasons for his alcohol abuse, all seem to have missed out on something very important. It has been missed because so many people have become wedded to the simple notion that there is one cause for one problem.
We have all seen so many television programs on which people have tearfully recounted the traumas that have befallen them, and we are then told that their current problems, whether of addiction, or of an inability to trust, or of serial infidelity, are all the result of having learned these behaviors, usually in childhood. So a person becomes an alcoholic because they saw their father drinking. An awful lot of therapy, and self-help is based upon that faulty premise. Why is it faulty? Because these people also share the same genes, and because, try as we might, we cannot reduce the whole of human behavior to ONLY learning, or ONLY genes. Most of the genes in the brain do not so much force you into behaving in a certain way; they instead predispose you to the way that you will handle something in your immediate environment.
So in the case of George Best, virtually all the tributes have said that the poor man become an alcoholic because he could not deal with all the fame, adulation and pressure that accompanied becoming soccer’s first real superstar. And doubtless, those were factors. But there is something else: his mother also died of complications of alcoholism, when she was 58 years old. Her drinking was attributed to watching her son succeed and then crash and burn. Possibly. But it is far more likely that it happened because they were both genetically predisposed to alcoholism.
When we try to understand a problem like this, it is essential not just to focus on the obvious cause: stress, or trauma, but also to look at the physical predisposition to reacting to the stress or trauma. Some people can be assailed by the most dreadful events, and come out smiling, while others have their lives ruined. It is also essential to look at the social context. George Best was brought from Belfast to Manchester when he was only 15 years old, and went home after two days because he was so homesick. He was persuaded to return to Manchester, and everyone tried to create a surrogate family for him, but it was obviously very difficult for him. It is also important to know that alcohol and substance abuse can cause havoc in the subtle systems of the body. That is why, when we treat people suffering form these illnesses, we encourage them to do some work, like Qigong or Yoga, to strengthen their subtle systems. Finally there is often a spiritual component to these problems. It is no coincidence that “spirits” as in alcohol and “spirit” as in spirituality, come from the same Latin root, in recognition of the ancient worship of the god Bacchus. Bill Wilson and Bob Smith recognized this link when they founded Alcoholics Anonymous in 1935. Many people who have struggled with addictions have been able to achieve sobriety once they discover and acknowledge the spiritual aspect of their lives, or in some cases that their substance abuse has been a reaction to a deep spiritual hunger.
Newsweek has an excellent article on the progress being made in our understanding of the physical components of addiction. The article highlights the complexity of the illness and the extraordinarily high relapse rates of sufferers.
There is only one quibble that I have with the article, and that is that it perpetuates the idea that substances of abuse hijack the “reward systems” of the brain. The reason why this is not quite correct is that it is a bit of a misnomer to talk about “reward systems.” These days we prefer to talk about salience systems. What does this mean? If something pleasurable happens to you, then the dopamine and GABA systems of the brain are indeed stimulated. And it appears that in substance abusers this system does not respond properly. So that they self-medicate because they have a form of sensory deprivation in these systems and that is the only way to get the dopamine levels that they need. But we now learn that dopamine also rises in the self same regions of the brain in response to threat. So what this system is doing is deciding what is salient, or important in the environment, and then focusing on and responding to it. It is these salience systems that seem to be under some genetic control, and can predispose someone to becoming a substance abuser.
Technorati tags: George Best alcoholism energy medicine
