Graham et al of both glucose and insulin concentrations in determining glucose uptake (Gottesman et al 1982). Insulin, anxiety, and depression There is a correlation between substance misuse and inappropriate compliance with treatment in chronic medical conditions, which can induce anxiety and depressive disorders (Weiss et al 1998). Insulin dependent diabetics (type 1) have higher co-morbid substance misuse compared with the general population (Kovacs et al 1997) and their compliance with their medical management is reduced (Morris et al 1997). Insulin dependent diabetics have an increased incidence of a psychiatric disorder, predominantly in the early course of their condition (Kovacs et al 1997). Treating the psychiatric disorder improves diabetic control (Lustman et al 1997). Hypoglycemia is a regular occurrence in insulin- dependent diabetics (Potter et al 1982) and may be associated with cognitive and affective outcomes (Gonder-Freerick et al 1997). Mood changes induced by ﬂuctuations in glycemic control are characteristically individual, with depressive and anxiety affective states being most prevalent, however euphoria can also occur (Gonder-Freerick et al 1989). The literature is interspersed with cases of deliberate misuse of insulin, associated with either suicide, parasuicide or facti- tious illness (Kaminer and Robbins 1989; Cassidy et al 1997). Even intelligent individuals have abused their therapeutically prescribed insulin to induce feelings of “happiness, disori- entation, drunkenness, altered perception of helplessness, and euphoria” (Cassidy et al 1997). However, there always appears to be an underlying mood or personality disorder (Scaramuzza et al 1996). There appears to be a class of individuals who are not diabetic and inject insulin to induce euphoria, to alter perception and for the “exquisite pleasure” associated with the risk of death (Odie 1968; Retsas 1972; Scarlett et al 1977). A cohort of patients referred to a deliberate self-harm team was asked to complete the HADS questionnaire. The HADS gave a sensitivity of 88% and a positive predictive value of 80% (Hamer 1991). Eighty percent of 56 hypogly- cemic patients admitted to an urban teaching hospital in a 12 month period were diabetics receiving insulin. Twenty percent were as a consequence of deliberate self-poisoning with insulin and had a history of psychiatric disorder (Hart and Frier 1998). A bodybuilder, who took 70 IU insulin for its anabolic effect, suffered hypoglycemic convulsions due to neuroglycopaenic coma (Konrad et al 1998). 594 Insulin effects on anthropometry, strength, and exercise performance Glucose metabolism significantly increased following exogenous insulin in trained athletes. V˙O2 peak also signiﬁ- cantly increased (Sato et al 1986). Insulin’s anabolic actions are believed to improve per- formance, by increasing protein synthesis (Bonadonna et al 1993; Kimball et al 1994) and inhibiting protein catabolism and enhancing transport of selected amino acids in human skeletal muscle (Biolo et al 1995). Physiological hyperin- sulinemia stimulates the activity of amino acid transport in human skeletal muscle, thereby stimulating protein synthesis (Bonadonna et al 1993). Insulin-treated diabetics are known to have increased lean body mass versus controls (Sinha et al 1996). In addi- tion to its role in regulating glucose metabolism, insulin increases amino acid transport into cells. Its stimulation of lipogenesis, and diminished lipolysis, is one of the reasons why bodybuilders and athletes will take rhGH in conjunction, to counteract this adverse effect, whilst optimizing protein synthesis (Sonksen 2001). It is the inhibition of proteolysis that the athlete is inter- ested in and the physiology of the diabetic patient has been extrapolated by the athlete to the sporting arena. Insulin administration is protein anabolic in the insulin-resistant state of chronic renal failure. It inhibits proteolysis and when administered with amino-acids, it increases net protein synthesis (Lim et al 2003). The administration of exogenous insulin, establishes an in-vivo hyperinsulinemic clamp, increasing muscle glyco- gen before and in the recovery stages of strenuous exercise. This may increase power, strength, and stamina and assist in recovery from strenuous exercise. Secondly, by inhibiting muscle protein breakdown and in conjunction with a high protein and high carbohydrate diet, insulin will have the action of increasing muscle bulk, potentially improving performance. Conclusion Strength and performance increase by the administration of rhGH and insulin in healthy young adults would appear possible by pharmacological manipulation, however cur- rent review of the literature suggests otherwise, in young, healthy, drug-naive individuals . Psychological improvement in abstinent AAS abusers by rhGH has been demonstrated (Graham et al 2007a), but no published research has been conducted in interventive insulin abuse in sport. Further research into the continued abuse of these drugs may assist Therapeutics and Clinical Risk Management 2008:4(3)