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I have paper already written but it needs some help to it!I will give more information!kanl;f;lem;lf;e;f;efde;kfl;edm;lfm;ldef;ked;kf;de;fk;edf;kfkfkfkffkfe;k;ked;fk;efkekfkaed;fkfkdsfkskkdefkdkf;k;kfkfkfs;sks;fksfkskfkskfsksk antidepressant_effects_of_physical_activity__1_.docx Unformatted Attachment Preview Antidepressant Effects of Physical Activity / 1 Antidepressant Effects of Physical Activity Physiological Foundations in Exercise Training and Rehabilitation Antidepressant Effects of Physical Activity / 2 Abstract Objective – To evaluate the short term effects of a training program on patients with moderate to severe major depression (Dimeo el at., 2001). Methods – Twelve patients (five men, seven women), mean age of 49, with major depressive episode according to the Diagnostic and Statistical Manual of the American Society of Psychiatry (DSM IV). The average duration of the depressive episode was 35 weeks (range 1296). Training consisted of walking on a treadmill following an interval training pattern and was carried out for 30 minutes a day for 10 days (Dimeo el at., 2001). Results – at the end of the training program, there was a clinically relevant and statistically significant reduction in depression scores (Dimeo el at., 2001). Conclusions – Aerobic exercise can produce considerable improvement in mood in patients with major depressive disorders in a short time (Dimeo el at., 2001). Introduction Depression has been ranked the leading cause of disability in the United States, with over $40 billion being spent each year on medical treatment and lost workplace productivity. Depression affects roughly 9\% of the U.S. adult population each year, and approximately 17\% of the U.S. population will suffer from a major depressive episode at some point in their lifetime. In between the years of 1987 and 1997, the rate of outpatient treatment has tripled and health care costs continue to rise associated with Major Depressive Disorder (Craft & Perna, 2004). Major Depressive Disorder (MDD) is an affective disorder that is characterized by a variety of symptoms including feelings of sadness, irritability, sleep deprivation, loss of appetite, Antidepressant Effects of Physical Activity / 3 feelings of worthlessness, loss of pleasure from enjoyable activities, and psychomotor impairment. Depression is twice as prevalent in females as in males, and a risk of reoccurrence can be as high as 50-90\% (Craft, 2005). With adolescents, depressive episodes are likely related to substance abuse, high levels of neuroticism, academic underachievement, unemployment, early parenthood, and suicide (Nabkasorn et al., 2005). About 10\% of those diagnosed with MDD commit suicide (Ernst et al., 2006). Treatment for MDD has primarily included psychotherapy and pharmacological interventions, predominately pharmacological therapy. Unfortunately, not always have these treatments been effective. For some, many have produced negative side effects. Furthermore, changes in health care have led to time constraints for therapy and limits in payment for mental health services (Craft, 2005). Since the 1990s, medical practitioners and researches have begun to examine exercise as a possible treatment alternative for MDD (Craft & Perna, 2004). The involvement in exercise has shown promise in alleviating symptoms of clinical depression. Early case studies have concluded that moderate-intensity exercise should be beneficial for depression and result in positive mood. Egil Martinsen (2008) compared aerobic exercise with occupational therapy for depressed patients and found exercise to be significantly effective. An important issue that has arisen with exercise having antidepressant effects is the type of exercise that has the best effect when treating depression. Many colleges have found no significant differences between non-resistance and resistance training as forms of treatment with those suffering from clinical depression. Martinsen (2008) also compared aerobic exercise with non-aerobic exercise and like many other researchers have found no significant difference Antidepressant Effects of Physical Activity / 4 between the two forms of training. Though different types of training can show similar effectiveness, other researchers have investigated that higher intensity training can be more alleviating than low intensity training. Some studies have been conducted to show the amount of energy expended during a workout has much to do with alleviating depression. Those with higher energy expenditures had larger depression reductions than those exercising at a lower intensity (Martinsen, 2008). Though knowledge about the relationship between physical activity and mental health are limited and varies greatly, there are many underlying mechanism that are hypothesized. The proposed mechanisms have been consistently research, but the underlying antidepressant effects of exercise still remain unclear. Physiological or biological mechanisms include the thermogenic hypothesis, the monoamine hypothesis, the endorphin hypothesis, and neurogenesis hypothesis. Along with physiological mechanisms, psychological mechanism may have beneficial effects. These hypotheses have been proposed to explain beneficial effects of physical activity on mental health. The psychological hypotheses include the distraction hypothesis and the self-efficacy hypothesis. Literature Review Physiological Mechanisms Thermogenic hypothesis states that the rise in core body temperature following exercise is responsible for the reduction in symptoms of depression. The rise in temperature in specific brain regions, such as the brain stem, can lead to an overall feeling of relaxation and reduction in muscular tension (Craft & Perna, 2004). Though the idea of increased body temperature has been proposed as a mechanism for the relationship between exercise and depression, the research Antidepressant Effects of Physical Activity / 5 conducted on the thermogenic hypothesis has only been examined on the effect of exercise and anxiety. The monoamine hypothesis is known to be the most promising among the physiological mechanisms. The hypothesis states that exercise leads to an increase in the availability of neurotransmitters (e.g. serotonin, dopamine, norepinephrine), which is how antidepressant drugs function. The occurrence of depression is cause by the diminishing of these neurotransmitters. These neurotransmitters are thought to maintain mood balance and emotional responses. Animal studies have shown that exercise increase serotonin and norepinephrine levels in various brain regions (Craft & Perna, 2004). Exercise has shown to elevate tryptophan hydroxylase (enzyme involved in the synthesis of serotonin) in the brain stem. Running has been found to increase the levels of tryptophan in the brain, which may lead to better mental health (Ernst et al., 2006). Endorphins are related to a positive mood and an overall enhanced sense of well-being. The endorphin hypothesis predicts that exercise has a positive effect on depression due to an increase in the release of endorphins following exercise. This hypothesis is mostly related to the feeling of runner’s high. Endorphins act as analgesics and sedatives, necessarily blocking the perception of pain. Several studies have shown increased levels of endorphins in acute and chronic exercise (Craft & Perna, 2004). The most recent hypothesis developed based on the biological mechanism of antidepressant effect of exercise is the neurogenesis hypothesis. Neurogenesis refers to the growth of new neurons in the adult brain. It has been hypothesized that a decrease in neurons in the hippocampus (bilateral structure in the brain known for learning and memory process) may be linked to MDD, and the action of antidepressant medications may promote neurogenesis. It Antidepressant Effects of Physical Activity / 6 has been discovered in animal studies that exercise increases the rate of neurogenesis and suggests a therapeutic effect of exercise on MDD (Ernst et al., 2006). With the development of new neurons, the neurons do not become fully functional until about four or five weeks. This latency period is similar to the onset of therapeutic treatment for those on antidepressant medications. There have been two distinct environmental influences that have been reported to stimulate neurogenesis. The first finding was that mice raised in an environment with toys and tunnels sustained levels of new neurons. The second was that the mice that were forced to learn a particular task were found to have more new neurons in comparison with those that did not learn new tasks. The animals that were engaged in exercise have been shown to undergo a sustained increase in neurogenesis in the hippocampus in comparison with those in a control group that did not engage in exercise. Mice that were given access to a running wheel for 2-4 months were found to have more than twice the number of new neurons than those in the control group with no running wheel (Ernst et al., 2006). Stated earlier, MDD is an affective disorder characterized by severe depressed mood and can disturb daily function, but pathologically MDD shows specific changes in the hippocampus. Brain scans have shown that MDD reduces the volume of the hippocampus in depressed patients than those compared with age-matched and sex-matched controls. These findings have only been found in a postmortem study. These findings are likely to be other precipitating factors that may contribute to these structural changes. Stress-induced hormones released from the adrenal gland (e.g. corticosteroids) can affect the hippocampus by decreasing neurogenesis. It has also been suggested that these hormones play a role in the decreased hippocampus volume. Too much Antidepressant Effects of Physical Activity / 7 stress can lead to immune dysfunction, depressed mood and changes in brain structure (Ernst et al., 2006). Psychological Mechanism The concept of distraction has been promoted as a possible mechanism for antidepressant effects of exercise. It has been thought that physical activity serves as interference from worries, anxiety, and depressing thoughts. Distraction refers to a response cycle in which an individual busies oneself in engaging in activity in attempt to focus on something other than depressive thoughts. An effective distracting activity engages the individual and has a high probability of providing opportunities for positive reinforcement. In general, the use of distracting activities as means of coping with depression has been shown to have a more positive influence on the management of depression than the use of more self-focused or introspective activities. When exercising, people usually focus on training goals or focus on somatic changes such as breathing, heart rate, or sore muscles and fatigue. Furthermore, the antidepressant effects of exercise may result from the ability of exercise to provide a periodic distraction from negative thoughts and feelings of depression (Craft, 2005). Exercise has been compared with other distracting activities such as relaxation, assertiveness training, health education, and social interaction. Results have been inconclusive, with exercise being more effective than the activities mentioned (Craft & Perna, 2004). Rumination is termed opposite of distraction as the tendency to passively and repeatedly focus on one’s negative thoughts. Rumination is thought to have a negative influence on the course of depression and may lead to continued depressed mood. Those who continue to focus on negative thoughts are at risk for prolonged bouts of depression. With continued rumination, Antidepressant Effects of Physical Activity / 8 the depressed person may experience helplessness, lowered self-esteem, and lack of motivation. Those who ruminate generally have more severe and longer lasting episodes of depression than those who use distraction as a response style (Craft, 2005). Research has shown that women spend more time ruminating than men, and that men tend to use distraction more than women. (Craft, 2005). Self-efficacy has been proposed as one mechanism by which exercise may help reduce symptoms of clinical depression. Self-efficacy refers to the level of confidence one feels when a challenge is met (Craft, 2005). It is believed that one possess the necessary skills to complete a task as well as the confidence that the task can actually be complete with the desired outcome one hopes. An efficacy belief directs the affective response through ones behavior, persistence, motivation, and effort of the chosen goal or task. Albert Bandura (1997) stated that healthy individuals are able to regulate their thoughts, feelings, and emotions toward seeking a completion of a goal or task. The belief one has to control a stressful situation and regulate their reactions to the situation is a primary determinant of how they will respond. Low levels of self-control can cause people to approach situations with anxiety and with little confidence. With low levels of self-efficacy, someone with depression can lead to negative ruminations and faulty styles of thinking. Furthermore, depressed individuals tend to blame themselves for negative life occurrences and can be prolonged with worsen depression (Craft, 2005). Several different factors can influence efficacy beliefs. The best source of efficacy comes from mastery of experiences. Those who can stay the course of action and follow a plan until a desired outcome is reached, will likely feel highly successful. Although on the contrary, repeated Antidepressant Effects of Physical Activity / 9 failures at mastery attempts can lead to feelings of depression (Craft, 2005). It can be argued that mastery of a new skill can lead to enhanced self-efficacy and reduction of depression. While learning new skills or hobbies and engaging in a mastery experience may lead to improvement in self-control. This can include mastering other health related skills (e.g. nutrition, weight management, health education) to enhance reduce depression level and improve quality of life. Craft (2005) has believed that enhancement of coping self-efficacy should be an important component of treating depression. The involvement in exercise programs provides meaningful mastery experience. If exercise is used as a therapy treatment of clinical depression, mastery should as well be emphasized. Overtraining Syndrome Peluso and Andrade (2005) developed an article on the negative side effects of exercise and how exercise can lead to depression and decreased mental health. Rather than biological and psychological mechanisms having the ability to improve mood, exercise and physical training can put restraints on social interaction. Some individuals train excessively and weight lifting becomes an obsession, thus leading to interference with personal and occupational relationships. Overtraining has even been defined as a factor when dealing with depressed patients. Overtraining symptom has pushed athletes to improve performance and reach his or her limits of physical capacity, or even slightly beyond. With excessive training, athletes do not experience sufficient rest and in this case present evident problems such as sleep disturbance, loss of weight and appetite, reduced libido, and even depression. The incidence of these symptoms occurring is estimated to be 7\% to 20\% per training season. With elite runners, this incidence can occur as high as 60\%. With swimmers the incidence can rise to 30\% (Peluso and Andrade, 2005). Antidepressant Effects of Physical Activity / 10 Benefits from aerobic exercise in patients with major depression: a pilot study Dimeo and coworkers (2001) conducted a study with all participants suffering from MDD according to the Diagnostic and Statistic Manual of the American Society of Psychiatry (DSM IV). The goal of the study was to evaluate the short-term effects of endurance exercise in patients with MDD. Twelve patients participated in the study. All patients have not had any change in treatment in six week preceding the training, hospitalization for at least two weeks without improvement, and a score of 15 or more on the HAMD scale. All patients have a current depressive episode of 35 weeks. Ten of the patients were suffering from refractory depression, which is defined as a lack of improvement after treatment from at least two separate antidepressant medications. Patients had their maximal physical performance assessed at the beginning and at the end of the study with a modified Bruce treadmill test under electrocardiogram monitoring. All patients carried out the test until exhaustion. Heart rate was assessed along with blood pressure and lactate concentration every three minutes. Maximal oxygen uptake in ml/kg/min was calculated according to the American College of Sports Medicine guidelines (Dimeo et al., 2001). Training consisted of daily walking on a treadmill. Training was carried out for ten days starting on Monday with a break on Sunday. The program was designed according to an interval training pattern. Patients carried out five training bouts of three minutes each. Between running bouts, patients walked at half speed for three minutes to recover. The intensity was evaluated daily using the Borg Rate of Perceived Exertion Scale. Heart rate was continuously recorded. When heart rate decreased due to training adaptation, the treadmill elevation was increased to Antidepressant Effects of Physical Activity / 11 maintain training intensity. The selected training intensity corresponded to a value of 13-14 on the Borg Scale (somewhat hard). Interaction was limited to only general comments about walking and training technique (Dimeo et al., 2001). The severity of depression was rated at the beginning and at the end of the program by a psychiatrist using the Hamilton Rate Scale for Depression (HAMD). Patients rated their mood from 0 (I feel bad) to 10 (I feel good), at the start of training, on the fifth training day, and at the end of the training program using the Scale for Self-assessment of Depression (D-S). D-S is a very common instrument used for self-evaluation of mood in German speaking countries. A reduction of 50\% on the HAMD or a final score of 10 or less required therapeutic intervention (Dimeo et al., 2001). Discussion Many reports do not describe the type, intensity, or frequency of exercise programs used as therapeutic intervention. Many studies modeling the effects of exercise on depressed patients have difficulty reproducing the same results. Also, their needs to be care when applying these findings with patients with affective disorders. A problem that remains is the lack of information about the psychiatric diagnosis of participation. Most studies when measuring depression scores use scales such as the Beck Depression Inventory which does not define patients as clinically depressed. The patients in Dimeo and coworkers (2001) study all were clinically depressed based according to DSM IV criteria. All patients completed the program without interruption. Results showed substantial improvement in six patients and slight improvement in two. In four patients, the severity of depressive symptoms remained unchanged. At the final examination, depression Antidepressant Effects of Physical Activity / 12 scores as a whole were significantly reduced. Maximal physical performance did not change during the study (Dimeo et al., 2001). In selected patients with MDD, aerobic training produces substantial improvements in depressive symptoms in a short time. Antidepressant drugs, which may relieve symptoms in about 60\% of patients, have a latency period of two to four weeks before any therapeutic effect occurs (Knubben et al., 2006) The observed outcome indicates a clinical benefit from physical activity that was not obtainable with pharmacological treatment. A significant percentage of patients have not shown improvement despite optimal dosage of antidepressants. For these patients, aerobic training can be offered a safe therapeutic option (Dimeo et al., 2001), or as a complementary treatment for the first 3 weeks of hospitalization until the antidepress ... Purchase answer to see full attachment