PSYCH 115 Lecture Notes - Lecture 2: Olanzapine, Psy, Atypical Antipsychotic
Document Summary
Bipolar disorder develops across a wide range of ages but tends to appear at two times. The second, slightly less common time, is between 35-45. Early onset tends to have a stronger family history and have a more severe presentation. As usual the vulnerability stress (i. e. : diathesis stress) model is preferred. However, there is more evidence for a heavy genetic contribution than in mdd. As in the case of schizophrenia, there is no clear evidence for a triggering effect of stressful events, but rather a broad indication that something more than genetics is at a play. Twin studies support a similar pattern to that of schizophrenia: 40-60% concordance for identical twins and only 4-10% concordance for fraternal twins. Family linkage studies looking at the likelihood of developing bipolar disorder if one has a. First degree relative with the disorder is 6x greater risk. Some research suggests that the genetic contribution to bipolar disorder is even stronger than for schizophrenia.
