NEWSLETTER - DECEMBER 2012
PREVENTIVE HEALTH - Screening for Mental Illness
Mental, emotional or psychological illnesses constitute the largest single health problem in most western societies. The incidence of mental illness has been estimated at 20-30% of the population, of which one quarter will be seriously disabled. Mortality from mental illness is mainly attributed to suicide. Suicide accounts for 30,000 deaths each year in the US compared with 18,000 from homicides and 40,000 from motor vehicle accidents.
Suicide is the main cause of death in males <35 years in the UK. The high rates of substance, alcohol and cigarette abuse and homelessness amongst the mentally ill, results in a high incidence of associated illness and a significantly reduced life expectancy.
The current plague of mental illness in western societies has coincided with the closure of many dedicated mental hospitals causing a significant reduction in hospital beds for the mentally ill. It was decided that the policy of treating mentally ill patients in separate institutions was undesirable and the mentally ill should be returned to the community. The lack of alternative provision for these patients means that most of them now end up as homeless or in prison. Estimates of mental illness amongst prison inmates vary from 70 to 90%. The high incidence of mentally ill individuals who are homeless or in prison has had the unfortunate consequence of converting a health problem into a social or law enforcement problem both in terms of cost and perception.
Any reading of the current mental health statistics in most western societies would conclude that the social and financial impact of mental illness is substantial, and yet mental illness remains one of the most neglected and underfunded areas of health provision. Under these circumstances it is not surprising that preventive measures, such as screening, receive scant support or attention.
At a more personal level, the impact of mental illness on family, friends and work colleagues can vary from irritating to devastating.
Difficulties in dealing with mental illness at a personal and governmental level can partly be attributed to two striking characteristics of this condition, the difficulty in establishing a precise and acceptable diagnosis and the social stigma attached to the illness.
Mental illness is different from other medical conditions because the diagnosis rests on symptoms reported by the patient or their family or friends. These symptoms such as “feeling depressed or “behaving oddly”, cannot be accurately measured, and require considerable linguistic skills to accurately convey the magnitude and effect of the symptom; linguistic skills that many individuals do not possess. The lack of measurement or test systems to
corroborate symptoms means that there are no reliable diagnostic tests. In many cases, this lack of independent confirmation can leave both doctor and patient wondering if the condition is imaginary.
The stigma attached to mental illness is considerable and prevents most patients from even considering such a diagnosis. Their condition, usually
expressed as abnormal behaviour, it often evident to close associates who are invariably reluctant to raise the possibility of mental illness, and therefore the condition remains undiagnosed and untreated.
A friend or relative who raises the possibility of mental illness is likely to be rebuffed and their friendship jeopardised. The standard response is often “what is normal”, or a total denial of unusual or inappropriate behaviour. A diagnosis of mental illness is often delayed until there is serious deterioration in interpersonal or professional relationships or aberrant behaviour results in some other major crisis.
Action of neurotransmitters in passage of nerve impulse
Many of the problems associated with the diagnosis and treatment of mental illness would be resolved if these conditions were recognised and accepted as physical ailments, with the same status as cardiovascular, musculoskeletal or other physical ailments. This would remove much of the fear and stigma and help to devise a standardised system of diagnosis and treatment.
There is growing recognition and acceptance of the fact that most, if not all mental illness can be explained by abnormal brain biochemistry, particularly abnormal levels of neurotransmitters. Neurotransmitters are chemicals which help to regulate and transmit impulses between nerve cells and target cells, and therefore control all body functions, particularly all brain functions.
Neurotransmitters such as serotonin, dopamine, epinephrine, norepinephrine, melatonin and gamma-aminobutyric acid (GABA) control a variety of mental and emotional functions or responses including mood, alertness, memory, cognition, appetite, aggression, submission, pleasure, reward, arousal and motor control. It is therefore not surprising that alteration to the function or levels of these neurotransmitters can have a marked effect on mental or emotional status.
Many of the medications used to treat mental illness act directly or indirectly on these neurotransmitters.
Antidepressants Norepinephrine, serotonin
Antipsychotic Serotonin, dopamine, histamine
MAOI Serotonin, epinephrine, norepinephrine, melatonin
Abnormalities of the neurotransmitter system may be inherited, may arise during development or may be the result of brain injury or other disease process.
The greatest advance in the diagnosis, treatment and social or cultural acceptance of mental illness will occur if and when these illnesses are unequivocally demonstrated to be physical ailments with a clearly defined mechanism that explains their symptoms.
Screening for mental illness will remain problematic as long as the social stigma remains, however there are a number of question and answer screening tests available on the internet which can be downloaded and completed in private. A positive screening test should prompt a visit to your medical practitioner to seek further advice.
Screening tests are available at http://www.mentalhealthscreening.org/ or www.mayoclinic.com/health/mental-illness or http://www.depressionscreening.org/
NEWS – Fibroblast Growth Factor implicated in schizophrenia
A number of recent studies have implicated yet another of the body’s chemical pathways in the development of mental or illness. Evidence is increasing that fibroblast growth factor 2 (FGF2) plays a major role in schizophrenia and mood disorders such as depression and bipolar disorder.
FGF2 is found mainly in the brain and is responsible for the protection and regeneration of neurons. It is also involved in the regrowth of glial cells which support and nourish neurons and produce the myelin that forms a protective sheath round the axon of nerve cells.
A decreased level of FGF2 has been shown to increase the severity of damage to neurons in brain injury, and to prevent or delay the regeneration of neurons.
It appears that neurons in the brain that wish to establish new connections or which require replacement after injury or death requires FGF2. Failure to replace damaged or dead neurons or to reinforce or establish new nerve connections will obviously affect how the brain functions.
Post-mortem studies in patients treated with selective serotonin reuptake inhibitors (SSRI’’s) have shown increased levels of FGF2 in the brain and administration of SSRI’s or clozapine (an antipsychotic) to rats has resulted in increased levels of FGF2 in the brain
Studies in rats have also shown that animals with high levels of anxiety have decreased levels of FGF2.
DID YOU KNOW – Serotonin controls digestion
Serotonin, one of the brains most important neurotransmitters is widely distributed in nature and is found in many animals and plants.
In primitive life forms such as the roundworm, serotonin regulates the rate at which food is ingested and pumped through the intestine, by controlling the rate at which the digestive muscles contract. When the worm encounters large populations of bacteria serotonin levels increase, allowing the worm to rapidly ingest the microorganisms.
Serotonin signal transmission between neurons
The role of serotonin in food digestion is maintained in evolved species such as modern humans. The majority (80%) of serotonin is secreted by enterochromaffin cells lining the digestive tract. These cells excrete serotonin in response to the presence of food allowing the nerves to trigger muscle contractions which pump the food through the intestine. When the intestine has received as much food as it can process, the excess serotonin triggers a feeling of satiety or fullness The presence of toxic or irritant substances in food increases serotonin secretion, speeding up the pumping mechanism to rapidly expel the food. If this process is not sufficient to remove the irritant food the excess serotonin will trigger the enteric and vagus nerves to induce vomiting.
In humans, serotonin levels are affected by diet, particularly by ingestion of carbohydrates. The ingestion of food rich in carbohydrates triggers the release of insulin which is responsible for the breakdown and storage of glucose and fats. Insulin also increases the absorption of amino acids with the exception of tryptophan. This effectively increases the concentration of
tryptophan in the amino acid pool and results in increased uptake of tryptophan across the blood brain barrier. Tryptophan in the brain is rapidly converted to serotonin.
Tryptophan is found in a variety of foods, however the ratio of tryptophan to other amino acids is more important than the concentration, as amino acids are competitively absorbed. Foods with a high level of tryptophan and a low level of other competing amino acids will produce an increase in serotonin when ingested. Examples are bananas, dates and papaya. Foods with a lower level of tryptophan and a high level of competing amino acids will cause a reduction in serotonin when ingested. Examples are wheat products and rye bread.
Serotonin can also be found in a number of plant seeds, where its presence may stimulate rapid passage of the seed through the digestive tract, when the fruit containing the seed is ingested. This may maintain the integrity of the seed and allow future germination.
Serotonin is a component of bee and wasp stings, where it is thought to be responsible for the pain sensation caused by vasoconstriction.