Depression is a common debilitative psychiatric condition ranked high in prevalence among all mental health conditions . Lifetime prevalence may be as high as 20%  and, at any one time, 5–10% of the world’s population meets diagnostic criteria for a major depressive episode . Depression is projected to be the second leading cause of disability worldwide in 2020 .
Clinical depression is common in primary care with rates of prevalence among older adults ranging between 4–24% [5, 6]. Untreated elderly patients are at higher risk of morbidity and mortality  and experience slower rates of recovery [6, 8]. Moreover, chronic depression is a significant risk factor for dementia .
Given that depression is amenable to treatment, valid and reliable screening tools are necessary to identify this patient population. Among existing instruments, the clinician-administered Hamilton Depression Rating Scale (HAM-D) was first developed to assess the efficacy of the first generation of antidepressant medications ; the HAM-D has since become the gold standard for measuring symptom severity and change in randomized clinical trials. Among various formats (17, 21, 24 & 28 items) [10, 11], the 17-item (HAM-D17) has been used most frequently. Scale items measure mood, insomnia, anhedonia, agitation, gastro-intestinal and other somatic symptoms, weight change, suicidal ideation, hypochondriasis, anosognosia, and psychomotor and cognitive retardation.
Despite widespread usage, various researchers have questioned whether the HAM-D17 is a unidimensional or multidimensional instrument [12–15]. This is problematic as multi-factorial measurement may impede the detection of symptom change over time, treatment response characteristics  and the ability to distinguish the relative efficacy of treatments . This assertion is supported by meta-analytic study findings indicating that certain scale items are less sensitive to measurement of symptom severity. In addition, some items have comparatively poor inter-rater and retest reliability, and the response-option format may not be optimal . In light of these findings, some have suggested that the 17-item HAM-D may be less than ideal for clinical research applications [14, 15, 17, 18].
These limitations have led researchers to propose abridged versions of the HAM-D that are quick to administer yet sensitive to measurement of symptom levels, change over time and relative differences in treatment efficacy. For instance, Maier and Philipp  proposed a 6-item version of the HAM-D. More recently, an 8-item version was devised by Gibbons and colleagues  by applying item response theory. Research to date suggests that both versions are sensitive to change over time and can identify patients in remission [21, 22]. Recently, a scale consisting of 7 items was also suggested . The items were empirically identified on the basis of response frequency and sensitivity to change of the individual HAM-D items with depressed samples .
Among the abridged versions of the Hamilton scale, the most frequently used was developed by Bech et al. (HAM-D6) . Using item analysis, these researchers  have proposed a 6-item HAM-D as a unidimensional measure of depressive symptomatology . This HAM-D6 is composed of items measuring core symptoms of depression (i.e., depressed mood, self-esteem and feelings of guilt, social interaction and interests, psychomotor retardation, anxiety, and somatic symptoms). Compared to the HAM-D17, this assessment appears to measure a unidimensional construct [13–15, 17, 25, 26], and it is as sensitive  or more sensitive in detecting drug–placebo or drug–drug differences [27, 28]. The authors of a recent study with older adults that compared six depression scales concluded that the HAM-D6 was the only one to demonstrate total scalability, and that it had the greatest external validity .
This scale, may be especially appropriate for use by both older persons and clinicians; its relative brevity makes it comparatively easy for older persons to complete and clinicians to administer. However, to the best of our knowledge, the psychometric properties of responses to the Hebrew HAM-D6 had yet to be examined. Thus, the current study examined and compared self-report and clinician responses to the Hebrew HAM-D6 for elderly patients.