Depression and Learned Helplessness Author Paul Kenyon Lecture outline The nature of depression Seligman's theory Learned helplessness theory Response contingency space Cognition and helplessness Weiss' theory Learned helplessness and human depression The motor activation deficit explanation of learned helplessness Testing the theories Stress and norepinephrine Test of the two theories Results Afterword References Further reading Visit the SALMON Bookshop for recommended books on this topic

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The Nature of Depression

Many people experience sadness following major trauma such as death in the family, divorce or job loss. This is not depression. Depression resembles sadness, but it is more severe and intense. In addition, whereas there is usually a reason for sadness, it can be difficult to account for the severity and intensity of depression in the light of the life events experienced by the sufferer.

Learned Helplessness Theory

Martin Seligman is responsible for the Learned Helplessness theory which had a major influence on psychological research into depression in the 1970s. Seligman discovered helplessness by accident whilst studying the effects of inescapable shock on active avoidance learning in dogs.

Seligman restrained dogs in a pavlovian harness and administered several shocks (UCS) paired with a conditioned stimulus (CS) - this is the conventional CS-UCS pairing procedure used to study classical conditioning . Then these dogs were placed in a shuttle-box where they could avoid shock by jumping over a barrier. The shuttle-box was used to study the role of operant conditioning in learning. Most of the dogs failed to learn to avoid shock.

From Swenson "Observational Learning Basics and history"

Seligman argued that prior exposure to inescapable shock interfered with the ability to learn in a situation where avoidance or escape was possible. Seligman used the term Learned Helplessness to describe this phenomenon.

It is important to emphasize that helplessness is > not an all-or-none phenomenon. Seligman studied the behaviour of about 150 dogs between 1965 and 1969. About 100 (2/3rds) were helpless after the administration of unavoidable electric shock in the pavlovian situation. The remaining 1/3rd were completely normal and learned to avoid shock in the avoidance learning test. There was no intermediate outcome - dogs either learnt to avoid, or passively accepted shock in the shuttle-box. Furthermore, about 5% of naive dogs that had never received inescapable shock, exhibited helplessness when first exposed to shock in the operant learning situation.

The central idea in the Learned Helplessness theory is the notion that all animals (including humans) are able to learn that reinforcers are > uncontrollable . This marks a sharp change in direction from previous studies of learning which had focussed on learning in controllable situations (Seligman,1992).

Response contingency space

Cognition and helplessness

It is important to appreciate that although cognition is at the heart of Seligman's theory, learned helplessness affects other psychological processes:

• motivation - reduced, no incentive to try new coping responses
• cognition - inability to learn new responses to overcome prior learning that trauma is uncontrollable
• emotion - the helpless state resembles depression

Seligman argues that there are similarities between the symptoms of depression in humans and helplessness

This concludes my very brief introduction to Learned Helplessness. I have had to omit many important ramifications of the theory, in particular predictions from the theory about the causes of depression and how it could be treated. Seligman goes into these topics in his very readable book: Seligman,M.E.P., > Helplessness , Freeman, New York, 1992.

I want to focus on one aspect of helplessness and depression that has posed problems for Seligman's theory: the physiological basis of Learned Helplessness. Seligman points out similarities between the physiological basis of depression and helplessness:

Weiss believes that 'learned helplessness' is produced by "some form of stress-induced 'debilitation'". He called this the > Motor Activation Deficit hypothesis (Weiss & Glazer, Psychosomatic Medicine, 37, p501, 1975). He highlights one important observation made by Overmier and Seligman in their original report of learned helplessness:

"They reported that poor avoidance-escape performance in the dogs was evident 24 hr after the session of inescapable shock but was totally absent if the dogs were first tested 48 hr after shock ."

(Weiss & Glazer, Psychosomatic Medicine, 37, p501, 1975, emphasis added)

Weiss has studied the effects of exposure to uncontrollable situations on norepinephrine (NE) metabolism in the brain (e.g. Weiss, J.M. et al, Psychosomatic Medicine, 37, 522-533, 1975).

Stress and norepinephrine

Weiss argues that rapid dissipation of the learned helplessness effect is not characteristic of learning, but instead indicates a short-term physiological imbalance that corrects itself with the passage of time from exposure to trauma. In support of this argument the diagram shows that NE level in the brain is: reduced shortly after exposure to inescapable shock, but recovers over the next 48 hours This suggests that the reason Seligman's dogs did not exhibit helplessness when tested 48 hr after uncontrollable shock was because brain NE had returned to normal by this time.

However, the effects of shock on brain chemistry depend upon prior experience.

Previous research has revealed that NE levels are not depleted if animals are given repeated exposure to uncontrollable shock.

Weiss used this information to design a clever experiment to test the two competing explanations of helplessness.

Rats were given repeated exposure to uncontrollable shock before being tested for their ability to learn an avoidance response in a shuttle-box.

• Learned Helplessness theory predicts that these rats should be helpless and should not be able to acquire the avoidance response
• The Motor Activation Deficit hypothesis predicts these rats should have normal NE levels and should acquire the avoidance response

This table is a simplified version of the treatments given to separate groups of rats in the experiment :

The results of Weiss & Glazers' experiment (Psychosomatic Medicine, 37, 523-534, 1975) together with the predictions made by the two theories are shown below in an interactive table that allows you to separately view the results of each experimental treatment. Click on the group names (S-S, NS-S, and NS-NS) to view the results for each independent group in the experiment. Compare each groups actual performance with the predictions made by the two theories.

Test of the two theories

		Theoretical Predictions
	Group	Learned Helplessness Theory	Motor Activation Deficit Hypothesis
	S-S	These helpless rats should not learn avoidance response	NE levels recovers with chronic shock. Rats should learn avoidance response
	NS-S	These helpless rats should not learn avoidance response	NE levels reduced. Rats should not learn avoidance response
	NS-NS	Rats should learn avoidance response	Rats should learn avoidance response
	Notes	Higher latencies indicate poorer learning. Short latencies indicate learning to avoid shock in presence of conditioned stimulus (CS) Click on blue underlined text to view individual group results Show all groups

The crucial group is the one given chronic exposure to shock before being tested in the shuttle-box (Group S-S) .

Results :

• Both theories predict that
  1. a single exposure to shock (Group NS-S) should interfere with learning in the shuttle-box
  2. rats with no prior experience with shock (Group NS-NS) should learn in the shuttle-box
• Both these predictions are confirmed by the results, therefore these results do not distinguish between the two theories.

However, contrary to the prediction of Learned Helplessness theory ,

• chronic exposure to inescapable shock (Group S-S) did not induce a state of helplessness that interfered with learning in the shuttle-box. this result supports the prediction made by Weiss' Motor Activation Deficit account of helplessness .

Afterword

In the late 1970s, Seligman's theory of depression was reformulated within the framework of attribution theory (Gilbert, 1984). Briefly depression will occur if:

• the individual is aware of uncontrollable factors in their environment
• the individual views the situation as unchangeable
• they blame themselves for their helplessness - internal attribution

This Wikipedia page has a useful discussion of "attributional reformulation" of learned helplessness

References

• Gilbert, Depression:From Psychology to Brain State, Lawrence Erlbaum Associates, London, 1984
• Lickey and Gordon, Medicine and Mental Illness , Freeman, New York, 1991
• Seligman, Helplessness , Freeman, New York, 1992
• Weiss, J.M. et al, Psychosomatic Medicine, 37, 522-533, 1975
• Weiss & Glazer, Psychosomatic Medicine, 37, p501, 1975,