Psychometric properties of the Subjective Well-Being Under Neuroleptics scale and the Subjective Deficit Syndrome Scale

Abstract

Rationale: Subjective experience of antipsychotic drugs is relevant for medication compliance and quality of life. There is, however, sparse knowledge about the assessment of subjective experience.

Objectives: To examine the internal consistency, test-retest reliability, sensitivity to medication change and concurrent validity of two test instruments: the Subjective Well-Being Under Neuroleptics (SWN) and the Subjective Deficit Syndrome Scale (SDSS).

Methods: Both instruments were used at admission and after 6 weeks of medication stabilization in 105 consecutively admitted patients diagnosed with DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th edn) diagnoses of recent-onset schizophrenia, schizophreniform disorder or schizoaffective disorder.

Results: Almost all patients were capable of reproducing their subjective experience in a consistent way both before and after medication stabilization. The internal consistency of both instruments was high. The test-retest reliability was high if medication was not changed, especially for the SWN. The SWN was sensitive for changes in medication and dosage. The short form of the SWN (SWN-20 items) had comparable psychometric qualities to the original instrument (SWN-38 items). The concurrent validity of the SWN and the SDSS was good, indicating that both tests measure the same concept.

Conclusions: The assessment of subjective experience with the SWN (both versions) may be used in evaluating differential effects of anti-psychotics and dose on subjective well-being.