Non-pharmacological strategies encompass a large variety of highly heterogeneous approaches. Many guidelines and various experts recommend non-pharmacological treatments as first-line treatment, but fail to recommend specific options [80-90, 93-95]. Synthesizing data in the form of, for example, meta-analyses is difficult since intervention methodologies vary, outcome measures differ, and the populations and settings are not comparable, or there is a lack of methodological rigor that limits evaluation of the efficacy of treatment [86, 87] . Moreover, evaluating the efficacy of non-pharmacological treatment on specific behaviors such as aggression, agitation, irritability, and hyperactivity is also hampered further by the fact that most studies examine the effects on BPSD in general. In this context, it is pertinent to highlight that lack of evidence does not equate to lack of efficacy.
In addition, the clinician may meet obstacles to implementing non-pharmacological approaches, which will need to be addressed in the first place. For example, carers may prefer drugs to non-pharmacological approaches due to their perception of the effectiveness of the latter and the fear that the patient they are caring for may become violent. Other obstacles include staff insufficiently trained in the use of non-pharmacological strategies and the time-consuming nature of the strategies.
As stated non-pharmacological strategies are heterogeneous and no consensus exists on the classification of treatments, in contrast to pharmacological treatments, which are often classified based on the mechanisms of action. Kales et al. (2015)  suggested dividing treatments into three categories: interventions aimed at the patient with dementia, interventions aimed at the carers, and interventions aimed at the environment. Livingston et al. (2014)  conducted a systematic review of non-pharmacological interventions with regard to their efficacy in treating agitation in patients with dementia. Here, interventions were divided into interventions working with the person with dementia, sensory interventions, working through care home staff, exercise, and training caregivers without supervision.