Mood disturbance and dysthymia are part of the clinical syndrome of hypogonadism. Epidemiological studies have found a positive association between testosterone levels and mood, and depressed aging males have lower testosterone levels than controls (Barrett-Connor, Von Muhlen et al 1999). Furthermore, induction of a hypogonadal state during treatment of men for prostate cancer leads to an increase in depression scores (Almeida et al 2004). Trials of testosterone treatment effects on mood have varied in outcome. Data on the effects on men with depression are conflicting (Seidman et al 2001; Pope et al 2003) but there is evidence that testosterone treatment of older hypogonadal men does result in improvements in mood (Wang et al 1996) and that this may occur through changes in regional brain perfusion (Azad et al 2003).
Inaccurate or misinterpreted test results can either falsely diagnose or miss a case of testosterone deficiency. Your testosterone level should be measured between 7 am and 10 am, when it's at its peak. Confirm a low reading with a second test on a different day. It may require multiple measurements and careful interpretation to establish bioavailable testosterone, or the amount of the hormone that is able to have effects on the body. Consider getting a second opinion from an endocrinologist.

Studies of the effects on cognition of testosterone treatment in non-cognitively impaired eugonadal and hypogonadal ageing males have shown varying results, with some showing beneficial effects on spatial cognition (Janowsky et al 1994; Cherrier et al 2001), verbal memory (Cherrier et al 2001) and working memory (Janowsky et al 2000), and others showing no effects (Sih et al 1997; Kenny et al 2002). Other trials have examined the effects of testosterone treatment in older men with Alzheimer’s disease or cognitive decline. Results have been promising, with two studies showing beneficial effects of testosterone treatment on spatial and verbal memory (Cherrier et al 2005b) and cognitive assessments including visual-spatial memory (Tan and Pu 2003), and a recent randomized controlled trial comparing placebo versus testosterone versus testosterone and an aromatase inhibitor suggesting that testosterone treatment improves spatial memory directly and verbal memory after conversion to estrogen (Cherrier et al 2005a). Not all studies have shown positive results (Kenny et al 2004; Lu et al 2005), and variations could be due to the different measures of cognitive abilities that were used and the cognitive state of men at baseline. The data from clinical trials offers evidence that testosterone may be beneficial for certain elements of cognitive function in the aging male with or without cognitive decline. Larger studies are needed to confirm and clarify these effects.
There are studies that show Soy consumption in humans leads to lower sperm count, but unfortunately they did not look at testosterone levels in the study (40). This (41) particular study compared the estrogen production of men drinking soy protein to those drinking whey. After two weeks they found the estradiol levels were equal, however soy drinkers had LOWER Testosterone levels and HIGHER cortisol levels (both bad).

The sexual hormone can encourage fair behavior. For the study, subjects took part in a behavioral experiment where the distribution of a real amount of money was decided. The rules allowed both fair and unfair offers. The negotiating partner could subsequently accept or decline the offer. The fairer the offer, the less probable a refusal by the negotiating partner. If no agreement was reached, neither party earned anything. Test subjects with an artificially enhanced testosterone level generally made better, fairer offers than those who received placebos, thus reducing the risk of a rejection of their offer to a minimum. Two later studies have empirically confirmed these results.[75][76][77] However men with high testosterone were significantly 27% less generous in an ultimatum game.[78] The Annual NY Academy of Sciences has also found anabolic steroid use which increase testosterone to be higher in teenagers, and this was associated with increased violence.[79] Studies have also found administered testosterone to increase verbal aggression and anger in some participants.[80]
This common kitchen spice can actually play a role in testosterone production.  It has been said that through supplementing with ginger, that users have the ability to not only increase testosterone production naturally, but also improve sexual function and drive, improve sperm health, as well as increasing sperm count.  This is great for infertile men as well as those looking for another avenue when it comes to boosting natural testosterone levels.  
Testosterone is significantly correlated with aggression and competitive behaviour and is directly facilitated by the latter. There are two theories on the role of testosterone in aggression and competition.[81] The first one is the challenge hypothesis which states that testosterone would increase during puberty thus facilitating reproductive and competitive behaviour which would include aggression.[81] Thus it is the challenge of competition among males of the species that facilitates aggression and violence.[81] Studies conducted have found direct correlation between testosterone and dominance especially among the most violent criminals in prison who had the highest testosterone levels.[81] The same research also found fathers (those outside competitive environments) had the lowest testosterone levels compared to other males.[81]
Most Americans today are sleep deprived, which may be a contributing factor to declining testosterone levels in men. See, our body makes nearly all the testosterone it needs for the day while we’re sleeping. That increased level of T that we experience at night is one of the reasons we wake up with “Morning Wood.” (If you don’t have Morning Wood on a consistent basis, you might have low T).

Vitamin D, a steroid hormone, is essential for the healthy development of the nucleus of the sperm cell, and helps maintain semen quality and sperm count. Vitamin D also increases levels of testosterone, which may boost libido. In one study, overweight men who were given vitamin D supplements had a significant increase in testosterone levels after one year.5

Hypogonadism is a disease in which the body is unable to produce normal amounts of testosterone due to a problem with the testicles or with the pituitary gland that controls the testicles. Testosterone replacement therapy can improve the signs and symptoms of low testosterone in these men. Doctors may prescribe testosterone as injections, pellets, patches or gels.