” Further studies are needed in which patients are instructed to watch the fish.”

I previously noted a brief reference in a book on high rise life to the role of aquaria in fighting loneliness. There is a fair amount written about the calming effects of contemplating aquaria. This paper attempts to study the phenomenon empirically in a (very) particular patient group. It is also an example of an abstract selling a result in the way the paper doesn’t support… “trend towards significance” indeed!

Anthrozoös Vol. 16 , Iss. 3,2003


This study investigates the effect of an aquarium on pre-treatment anxiety, fear. frustration, and depression in electroconvulsive therapy (ECT) patients. Forty-two patients consecutively referred for ECT were rotated between rooms with and without aquariums. Self report measures of depression, anxiety, fear, and frustration were obtained, along with heart rate and blood pressure measurements. Preliminary mixed-model, repeated measures analysis of variance (ANOVA) revealed no significant differences between the aquarium and control conditions on any of the dependent measures. A trend toward significance was found for self reported anxiety (p=0.08) and further data were collected. Subsequent mixed model, repeated measures ANOVA confirmed the trend toward differences (p=0.08) in anxiety between the aquarium and control conditions. Factoring out demographic factors, the average patient experienced 12% less anxiety in the presence of an aquarium.

The authors describe how ECT is an effective, evidence-based psychiatric treatment, but that pre-treatment anxiety is an issue. Prior interventions have not been found significantly effective:

Educational interventions have been primarily developed to address this fear and anxiety; however, conflicting results have been reported regarding their effectiveness. One study focused on the effect of emotional support, provided by a psychiatric nurse in an educational context, on the anxiety levels of 32 ECT patients (Cohen 1970). The results revealed no significant difference in anxiety levels between patients receiving the intervention and those who did not. Another study involving 37 veteran psychiatric patients reported that while knowledge and behavioral intent showed positive changes following an educational ECT video, there was no reduction in fear (Battersby, Ben-Tovim and Eden 1993). Contrary results were reported using a continuous quality improvement model in which an educational video and written information were found to reduce anxiety. These findings are based on follow-up telephone interviews from15 patients (Harrison and Kaarsemaker 2000).

The authors describe animal-assisted therapy:

One environmental intervention, animal-assisted therapy (AAT), has been found to calm patients in some circum-; the benefits of interacting with companion animals are receiving increased attention in the healthcare industry. Studies have documented an association between pet ownership and reduced cardiovascular risk factors,improved one-year survival rates following myocardial infarction, reduction in minor health problems, and lower physician utilization (Friedmann et al.1980; Siegel 1990; Serpell 1991; Anderson, Reid and Jennings 1992). More recently, randomized controlled studies have shown a positive effect of pet ownership, or the presence of pets, on physiological indicators of reactivestress (Allen et al. 1991; Allen 2000; Allen, Shykoff and Izzo 2001; Allen,Blascovich and Mendes 2002). Interacting with companion animals has also been associated with reduced anxiety levels for non-psychiatric as well as inpatient psychiatric populations (Wilson 1991; Barker and Dawson1998). A significant reduction in anxiety was reported in a study involving 241 hospitalized psychiatric patients with a broad range of diagnoses fol-lowing 30 minutes of animal-assisted therapy (Barker and Dawson 1998).A more recent study found a significant reduction in fear following a 15-minute interaction with a therapy dog and its handler for 35 psychiatric patients waiting for electroconvulsive therapy (Barker, Pandurangi and Best 2003). No significant differences were found for anxiety or depression.

The authors describe the limitations of this study. One strikes me as fairly fundmental – patients were not asked to look at, or engage with the aquarium…. and in fact couldn’t, by and large, actually see it :

Similar to the results reported by Katcher, Segal and Beck (1984),blood pressure and heart rate readings were not significantly different for the patients in the aquarium and control conditions: the presence of an aquarium was not associated with reduced physiological measures of anxiety in patients waiting for ECT. However, unlike the earlier Katcher, Segaland Beck study, patients in this study were not asked to look at, or in anyway attend to, the aquarium, nor was it suggested to them that the aquarium would have a calming effect. Instead, the purpose of this study was to assess the impact of the mere presence of a fish aquarium. Further studies are needed in which patients are instructed to watch the fish.

The lack of significant findings in the present study may also be in part due to the background role of the aquarium. As patients were not seated in front of the aquarium or asked to look at it, they were not intentionally exposed to the potentially calming effect of watching the fish, unless they deliberately chose to do so. Most patients tended to lie down while in the holding rooms. In order to view the fish in this position, they would have to deliberately lie on one side. It may be necessary for patients to focus on the aquarium to derive benefit; a task that may be difficult for severely depressed patients. Also, the aquarium may not represent a powerful enough stimulus to distract patients from thoughts of their upcoming ECT treatment.

As neither study resulted in a significant reduction in anxiety, it maybe that the anxiety related to the ECT procedure is not amenable to the calming effects of animal-assisted activities. Also, the global nature of the visual analog scales used in both studies may not be sensitive to anxiety changes resulting from animal-assisted activities.

It does strike me that, as ECT is now reserved for specific indications and, by definition, those most severely ill, the anxiety and distress associated is likely to be at the more severe end of the spectrum – and less likely to respond to the passive presence of an aquarium.