SR4a pg 191 The Assensing Table
1 Hit can get you "The subject’s general emotional state or impression (happy, sad, angry)."
3 Hits can get you "A general diagnosis for any maladies (diseases or toxins) the subject suffers."
Street Magic pg 141
QUOTE
Toxic magicians are Awakened characters whose sanity, outlook, and magic have become tainted by environmental blight or human desolation.
As the toxic magician’s approach to magic transforms due to his personal insanity, he develops his own ways to practice magic. Toxic magicians still follow the basic rules of a tradition, but each toxic magician pursues his own personally-warped paradigm and concept—and thus follows a unique tradition that fits his agenda. This personal toxic tradition determines which five toxic spirits he can summon and which attribute is employed for Drain.
I'd call insanity an Emotional State or Malady.
So BishopMcQ is correct, there is no definiative Toxic Mage/Shamen Test roll. There are however many means to gather the components for your PCs to digest.