The exploratory model is based on the stress model that was developed by Lazarus and Folkman (
10) and on previous research and clinical observation. In our model, family burden during an acute episode was hypothesized to influence clinical outcome, both directly and indirectly, through the family's affective response toward the patient, as represented by expressed emotion (
6). Because studies have consistently demonstrated that higher levels of expressed emotion predict relapse among patients who have either affective illness or schizophrenia (
11,
12) and have found that expressed emotion and its components are positively correlated with measures of family burden (
13,
14), we examined the relationship of these two constructs in relation to patient outcome. Consistent with the stress and coping theory (
10), which suggests that cognitive and affective evaluation of the degree of threat posed by the stressor precedes the individual's response, we placed family burden ratings, which consist of both a cognitive and an affective appraisal of the degree of problems posed by the patient's illness (
15), antecedent to expressed emotion scores, which reflect the family's behavior toward the patient (
6). Because some studies have shown differential associations of the main expressed emotion components—critical comments and emotional overinvolvement—with burden (
13), we represented these dimensions separately in our model. However, we hypothesized that higher levels of burden would be associated with higher levels of both critical comments and emotional overinvolvement.
We included an evaluation of medication adherence at baseline and at the seven-month follow-up in our model because adequate pharmacotherapy is an important predictor of clinical outcome among patients with bipolar disorder (
16,
17,
18,
19). Because clinical observation suggests that medication adherence is a frequent object of disagreement between patient and family, we hypothesized that burden, critical comments, and emotional overinvolvement would affect clinical outcome both directly and indirectly through an effect on medication adherence. Specifically we hypothesized that higher levels of burden would be associated with higher levels of both critical comments and emotional overinvolvement.
Finally, we included as covariates variables that previous studies have found to predict burden (symptom severity, whether the patient lives with the caregiver, and caregiver stigma) (
4,
5,
20,
21,
22) or critical comments and emotional overinvolvement (the caregiver's relationship to the patient) (
23). However, we did not hypothesize direct effects of these variables on clinical outcome because we did not believe that these variables would have a direct effect on outcome. Higher levels of symptom severity and caregiver stigma as well as living with the patient and being a spouse were hypothesized to be related to higher levels of burden, critical comments, or emotional overinvolvement. Clinical outcome was indexed by whether or not the patient met diagnostic criteria for a current affective episode of either pole at the 15-month follow-up point. Because our study was exploratory and had a limited sample size, we did not include all possible paths but selected those with primary theoretical relevance or previous research associations.