Assessment of insight into delusional beliefs in schizophrenia using the Brown Assessment of Beliefs Scale

Dear Editors,

Insight has important diagnostic and prognostic value in schizophrenia (Amador et al., 1994). Several important scales evaluate insight in a variety of mental illnesses, including the Scale to Assess Unawareness of Mental Disorder (SUMD; Amador et al., 1994)and the Insight and Treatment Attitudes Questionnaire (McEvoy et al., 1989). The Brown Assessment of Beliefs Scale (BABS) is an efficient, seven-item, semi-structured, clinician-administered scale that measures insight/delusional thinking in a variety of mental illnesses (Eisen et al., 1998). It assesses the following components of insight/delusionality: conviction, perception of others’ views, explanation of differing views, fixity of beliefs, attempts to disprove beliefs, insight (recognition that the belief has a psychiatric/psychological cause), and referential thinking (referential thinking is not included in the total score). The BABS has strong psychometric properties, including sensitivity to change, inter-rater and test-retest reliability, internal consistency and convergent validity with other insight measures (Eisen et al., 1998).

In this report, we present pilot data using the BABS to assess insight into delusional beliefs in patients with schizophrenia. Prior to administration of the BABS, the patient’s dominant belief during the past week was established; the scale was completed in 10-15 min. Responses from the BABS were compared to the SUMD using Pearson’s correlation. A second rater measured global insight using an anchor from the Yale-Brown Obsessive Compulsive Scale (Goodman et al., 1989). Two additional measures of delusionality were administered: the Dimensions of Delusional Experience (DDE) scale (Kendler et al., 1983) and Characteristics of Delusional Experience Scale (CDES) (Garety and Hemsley, 1987). The BABS’ ability to discriminate insight from general psychosis was examined using the Brief Psychiatric Rating Scale (BPRS; Overall and Gorham, 1962) and the Scales for the Assessment of Positive Symptoms (SAPS; Andreasen, 1983) and Negative Symptoms (SANS; Andreasen, 1984).

Sixteen outpatients in various stages of treatment were recruited from the Providence Veterans Affairs Medical Center. DSM-IV diagnoses were made based on a clinical interview (by G.B.K.), extensive records, and the psychotic module of the Structured Clinical Interview for DSM-IV (First et al., 1996). Ten subjects were diagnosed with schizophrenia and 6 with schizoaffective disorder. Fifteen subjects were male. The mean age was 47.6 years, and all were receiving antipsychotic medication. The mean BPRS, SAPS, and SANS scores were 47.8, 40.3, and 43.6, respectively, indicating moderately severe psychosis and psychopathology.

The total BABS score correlated significantly with the SUMD score (r = 0.55; P b 0.05) (Table 1). The BABS’ conviction item was correlated with the conviction items on the DDE (r = 0.66; P b 0.001) and CDES (r = 0.62; P b 0.05). Cronbach’s alpha coefficient was 0.89, suggesting that the BABS is adequately homogenous. Correlations between each BABS item and the total BABS score minus that item’s score ranged from r = 0.48-0.78. All of these correlations were significant at P b 0.05 except for that between the BABS insight item and total BABS score, for which a trend was found (P = 0.06). The BABS total score was not significantly correlated with DDE or CDES total scores or the clinician’s independent global insight rating. The BABS total score was not correlated with scales measuring positive and negative symptoms and psychopathology in schizophrenia (BPRS, SANS, SAPS). This lack of correlation between the BABS and other scales could reflect discrimination between these measures or the small sample size.

Table 1.

Correlation matrix of Spearman r values for measures of insight, delusional beliefs, and psychopathology in patients with schizophrenia and schizoaffective disorder

Spearman r values	BPRS	SANS	SAPS	BABS	CDES	DDE	INSIGHT	SUMD
BPRS	1.00	0.41	0.53a	0.34	0.12	0.23	-0.13	0.52a
SANS		1.00	-0.13	0.17	-0.12	-0.26	-0.32	0.46
SAPS			1.00	0.23	0.44	0.71b	0.17	0.43
BABS				1.00	0.22	0.42	0.24	0.55a
CDES					1.00	0.74b	0.24	0.51
DDE						1.00	0.29	0.48
INSIGHT							1.00	0.25
SUMD								1.00

^aP <0.05.

^bP <0.005.

In this pilot study, the BABS was internally consistent and correlated with an established insight measure (SUMD). Further studies on the utility of the BABS in schizophrenia are warranted in larger samples. The BABS demonstrates utility across a range of mental illnesses, is easily and quickly administered, and assesses multiple components of delusional thinking.