How likely is it for effexor (venlafaxine) xr 150mg to trigger mania and to what degree?

Definitely can if: You are new to it and/or your dose was recently increased. This process of kindling can also happen with ssri's and psychostimulants. It is a matter of balance: mood needs to be stabilzed first in bipolar disorder or 1-2 months and then one of the above medications can be used for remainder anxiety, depression etc. I do not see appropriate mood stabilizer in your list.Please call ur psychiatrist.

Controversial: The use of antidepressants (AD) in bipolar d/o is controversial. Some physicians will never use an AD in bipolar d/o and instead prefer mood stabilizers with AD properties (lithium). Other physicians do use AD in bipolar d/o. It really depends on the patient and how he/she has responded in the past. However if an AD is used, the patient generally should be on a mood stabilizer to prevent mania.