How to increase serotonin in the human brain without drugs.

For the last 4 decades, the question of how to manipulate the serotonergic system with drugs has been an important area of research in biological psychiatry, and this research has led to advances in the treatment of depression. Research on the association between various polymorphisms and depression supports the idea that serotonin plays a role, not only in the treatment of depression but also in susceptibility to depression and suicide. The research focus here has been on polymorphisms of the serotonin transporter, but other serotoninrelated genes may also be involved. In the future, genetic research will make it possible to predict with increasing accuracy who is susceptible to depression. Much less attention has been given to how this information will be used for the benefit of individuals with a serotonin-related susceptibility to depression, and little evidence exists concerning strategies to prevent depression in those with such a susceptibility. Various studies have looked at early intervention in those with prodromal symptoms as well as at population strategies for preventing depression. Obviously, prevention is preferable to early intervention; moreover, although population strategies are important, they are ideally supplemented with preventive interventions that can be used over long periods of time in targeted individuals who do not yet exhibit even nonclinical symptoms. Clearly, pharmacologic approaches are not appropriate, and given the evidence for serotonin’s role in the etiology and treatment of depression, nonpharmacologic methods of increasing serotonin are potential candidates to test for their ability to prevent depression. Another reason for pursuing nonpharmacologic methods of increasing serotonin arises from the increasing recognition that happiness and well-being are important, both as factors protecting against mental and physical disorders and in their own right. Conversely, negative moods are associated with negative outcomes. For example, the negative mood hostility is a risk factor for many disorders. For the sake of brevity, hostility is discussed here mainly in relation to one of the biggest sources of mortality, coronary heart disease (CHD). A meta-analysis of 45 studies demonstrated that hostility is a risk factor for CHD and for all-cause mortality. More recent research confirms this. Hostility is associated not only with the development of CHD but also with poorer survival in coronary artery disease (CAD) patients. Hostility may lead to decreased social support and social isolation, and low perceived social support is associated with greater mortality in those with CAD. Effects are not just limited to CHD. For example, the opposite of hostility, agreeableness, was a significant protective factor against mortality in a sample of older, frail participants. The constitution of the WHO states “Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.” This may sound exaggerated but positive mood within the normal range is an important predictor of health and longevity. In a classic study, those in the lowest quartile for positive emotions, rated from autobiographies written at a mean age of 22 years, died on average 10 years earlier than those in the highest quartile. Even taking into account possible confounders, other studies “found the same solid link between feeling good and living longer.” In a series of recent studies, negative emotions were associated with increased disability due to mental and physical disorders, increased incidence of depression, increased suicide and increased mortality up to 2 decades later. Positive emotions protected against these outcomes. A recent review including meta-analyses assessed cross-sectional, longitudinal and experimental studies and concluded that happiness is associated with and precedes numerous successful outcomes. Mood may influence social behaviour, and social support is one of the most studied psychosocial factors in relation to health and disease. Low social support is associated with higher levels of stress, depression, dysthymia and posttraumatic stress disorder and with increased morbidity and mortality from a host of medical illnesses.