"Initial signs that anabolic steroids are being abused may include rapid weight gain and unusual mood swings. Emotions may include increased aggressiveness. Acne is almost always seen.
The side effects of steroids can be explained by the excess androgen and anabolic drug levels present in the body.
The use of steroids suppresses .... more here
Oscar Pistorius's brutal killing of his girlfriend immediately reminded me of the the "Roid Rage" that is often experienced when taking anabolic steroids. As more detail comes to light, the more it seems he totally lost the plot.
Steroid use is most effective out of season during the bulking and strength phases of an athlete's conditioning. This would fit timing-wise with regards to Pistorius's preparations for the up-coming season.
It will be interesting to see what comes out in the court proceedings.