Srimadbhagwad Gita clearly mentions anger as door for hell. Even Charak Samhita refers anger to be avoided by wise people. Modern medical science deals it as feeling of annoyance, displeasure and hostility. Excessive anger is related with many of psychological problems including attention deficit disorder, conduct disorder, psychotic disorder, personality disorder, bipolar disorder etc.
Bipolar disorder is easily identified with extreme shifts in mood. It may be resulted from changing neurochemicals due to various reasons viz., altered brain structure, genetics, environmental etc. A study has observed structural brain abnormalities in prefrontal cortex while another study finds family history responsible for affective disorder. Limbic and extrapyramidal circuit is involved in this case following cortico-ganglio-thalamo-cortical tracks. The limbic system deals with emotions and memory while extrapyramidal circuit is related to motor cortex through the pyramids of medulla for involuntary actions. A separate study reveals more stimulation of left hemisphere of brain during anger.
Recently in a study done at University of Valencia, it is revealed that anger is linked with increased testosterone and decreased cortisol. Increased testosterone is proven for its negative and positive stimuli while decreased cortisol is associated with mood swing through hypothalamic-pituitary-adrenal axis. Interestingly, the levels of testosterone were found decreased in male and increased in female suffering from bipolar depressive disorder. Both bipolar disorder and anger are connected with levels of metabolites in cerebrospinal fluids, monoamine depletion and neuroendocrine.
Meditation is best way to control anger and anger-associated bipolar disorder. Larger amount of gray matters in hippocampus and frontal areas of brain are found affiliated with meditation. It is further proven that gray matters are interconnected with positive emotions. Positive emotions are an important tool to control anger.