events. Aripiprazole was the first drug approved by the US Food and Drug Administration for adjunctive treatment of MDD in adults with inadequate response to antidepressant therapy in the current episode. Recommended doses of aripiprazole range from 2 mg/d to 15 mg/d based on 2 large, multicenter randomized, double-blind, placebo-controlled studies, which were later supported by a third large trial. Most conventional antipsychotics, such as the phenothiazines, work by blocking the D2 Dopamine receptors. Atypical antipsychotics, such as clozapine block both the D2 Dopamine receptors as well as 5HT2A serotonin receptors. Atypical antipsychotics are favored over conventional antipsychotics because they reduce the prevalence of pseudoparkinsonism which causes tremors and muscular rigidity similar to Parkinson’s disease. The most severe side effect of antipsychotics is agranulocytosis, a depression of white blood cell count with unknown cause, and some patients may also experience photosensitivity. Antidepressant Early antidepressants were discovered through research on treating tuberculosis and yielded the class of antidepressants known as monoamine oxidase inhibitors (MAO). Only two MAO inhibitors remain on the market in the United States because they alter the metabolism of the dietary amino acid tyramine which can lead to a hypertensive crisis. Research on improving phenothiazine antipsychotics led to the development of tricyclic antidepressants which inhibit synaptic uptake of the neurotransmitters norepinephrine and serotonin. SSRIs or selective serotonin reuptake inhibitors are the most frequently used antidepressant. These drugs share many similarities with the tricyclic antidepressants but are more selective in their action. The greatest risk of the SSRIs is an increase in violent and suicidal behavior, particularly in children and adolescents. In 2006 antidepressant sales worldwide totaled $15 billion USD and over 226 million prescriptions were given. Research on the effects of physical activity on mental illness Research completed As increasing evidence of the benefits of physical activity has become apparent, research on the mental benefits of physical activity has been examined. While it was originally believed that physical activity only slightly benefits mood and mental state, overtime positive mental effects from physical activity became more pronounced. Scientists began completing studies, which were often highly problematic due to problems such as getting patients to complete their trials, controlling for all possible variables, and finding adequate ways to test progress. Data were often collected through case and population studies, allowing for less control, but still gathering observations. More recently studies have begun to have more established methods in an attempt