Background Late onset hypogonadism negatively impacts on men's psychological well-being.This study was conducted to examine the interrelationship among symptoms of testosterone deficiency,psychological well-being,and quality of life.Methods Eligible subjects were randomized into active treatment and control groups,and were asked to complete the following questionnaires at baseline and month 6:aging male's symptoms (AMS) rating scale,hospital anxiety and depression scale (HADS),perceived stress scale (PSS) and the short form health survey-12 (SF-12).In this study,men were treated and monitored for 6 months with oral testosterone undecanoate (TU) capsules or vitamin E/C capsules in a single-blinded fashion.All in the active treatment group were administered a total of 120-160 mg TU orally on a daily basis.Total and free T levels between baseline and month 6 were compared.Results One hundred and sixty eligible subjects were recruited and followed up.In the active treatment group,total serum testosterone concentrations before and after intervention were (7.98±0.73) nmol/L and (13.7±1.18) nmol/L.The mean HADS anxiety subscale scores for the subjects at baseline and at month 6 were 3.47±0.4 and 1.72±0.2,respectively (t=1.526,P＜0.05).Additionally,the mean HADS depression subscale scores were 4.91±0.6 and 2.39±0.3,respectively (t=3.466,P＜0.05).The mean scores on PSS for the subjects at baseline and at month 6 were 12.88±2.1 and 9.83±1.7,respectively (t=4.009,P＜0.05).Significantly improved SF-12 could be observed (t=1.433 and 1.118,respectively; both P＜0.05).No significant changes were observed in the control group at month 6.Conclusion Androgen replacement not only improves androgen deficiency associated symptoms,but also enhances comprehensive improvement in psychological issues.(No.ChiCTR-TRC-11001811)