Did I lock the door? The cognitive neuroscience of Obsessive-Compulsive Disorder

Hampshire College

Brain and Cognition

Introduction

Obsessive-Compulsive Disorder (OCD) is a common disorder that appears in both children and adults. It consists of obsessions, compulsions, or both. Obsessions consist of recurring thoughts or impulses that are intrusive and unwarranted by the environment (but still perceived as originating from the patients own mind, distinguishing them from “though-insertion”), causing distress or anxiety, and compulsions are repetitive behaviors the obsessive-compulsive feels he/she must perform. Compulsions are often related to the obsessions, and are meant to neutralize the distress caused by such obsessions. Some of the most common obsessions include germaphobia, fear of causing harm to oneself or to others, and worrying that important tasks have been left undone, for example being unsure whether one has locked the door, and compulsions include behavior such as hand washing, counting, and checking. The patient is usually aware of the absurdity of their thoughts and actions, but nevertheless feels powerless to stop them (American Psychological Association, 2000).
In this paper, I will discuss the neurocognitive findings regarding OCD, particularly as they relate to the SEC/OCD model proposed by Huey et al (2008). I will begin with an overview of some of the brain studies of OCD, moving on to some popular models of the disorder. Finally, I will discuss the SEC/OCD model.

The Brain Regions Implicated in OCD and their Functions

Despite copious amounts of research, the precise neuropsychology of OCD is uncertain (Markarian et al, 2010). Different studies often provide different and even contradictory results. Despite this, there are some generally agreed upon neuroanatomical features of OCD. Specifically, it has been consistently found that obsessive-compulsives reveal anatomical and functional abnormalities in the orbitofrontal cortex and the anterior cingulate cortex, and also the basal ganglia, prefrontal cortex, and thalamus (Markarian et al, 2010; Huey et al, 2008).

Several studies have reported reduced bilateral orbitofrontal cortex volumes in obsessive-compulsives, and there seems to be a correlation between greater reductions and worse symptoms (Maia, Cooney, & Peterson, 2008). The orbitofrontal cortex seems to be involved in reward learning and emotions, and the regulation of complex behavior. It has been found that the orbitofrontal cortex responds to reward stimuli, but not when the desire for the stimuli has been satiated. Macaques with orbitofrontal have difficulty learning the reward value of stimuli, and are slow to change their behavior when reward conditions change (Huey et al, 2008).

There is evidence of increased anterior cingulate cortex activation in obsessive-compulsives (Fitzgerald et al, 2005). The anterior cingulate cortex is implicated in decision-making. In particular, it acts as a conflict and error detector, responding when there is a discrepancy between expected and actual events. Activation of the anterior cingulate cortex seems to lead to negative emotional states, such as anxiety (Huey et al, 2008).

It has been found that damage to the basal ganglia through infection can lead to obsessive-compulsive symptoms. The basal ganglia seem to play an important role in the generation and regulation of motor activities. Specifically, it has been suggested that the basal ganglia acts as a sort of gate for motor signals, facilitating certain motor actions while suppressing others (Huey et al, 2008).

The thalamus shows higher activation in subjects with OCD compared to controls, and has been reported to be larger in obsessive-compulsives (Maia, Cooney, & Peterson, 2008; Huey et al, 2008)). The thalamus seems to be a gateway for interactions between brain areas involved in OCD (Huey et al, 2008).

Some Models of Obsessive-Compulsive Disorder

Based on behavioral and neuroanatomical evidence, there have been numerous models proposed for OCD.

The Cognitive-Behavioral Model: According to this model, OCD arises from dysfunctional beliefs regarding the importance of thoughts. Almost everyone has had intrusive thoughts that are perceived as inappropriate: for example, the fleeting, unwarranted, and unwanted mental image of stabbing a loved one with a knife. Healthy subjects recognize this as just meaningless junk in the stream of consciousness. However, obsessive-compulsives, according to the cognitive-behavioral model, incorrectly view these thoughts as highly significant—for example, as evidence that one will, in fact, lose control and stab someone. Because of the importance attached to these thoughts, they develop into obsessions, and compulsions arise as a way to attempt to get rid of these unwanted thoughts and/or neutralize the danger associated with such thoughts. These compulsions are then reinforced by the temporary reduction in anxiety they cause and the fact that they prevent the obsessive-compulsive from learning that harmful consequences will not arise as the result of their thoughts (McKay & Abramowitz, 2010). This model has gathered a lot of support (with some exceptions), but does not provide a neuropsychological explanation.

The Standard Model: The standard neuroanatomical model of OCD proposes that the disorder arises as a dysfunction of elements of a post-frontal cortex-basal ganglia-thalamic loop. This model is consistent with most of the data collected on the neuroanatomy of OCD and forms the basis of many following models. However, it does not explain the psychological mechanisms of OCD (Huey et al, 2008).

The “Feeling of Knowing” Model: Szechtman & Woody (2004) propose a model wherein OCD is caused by an inability to create the “feeling of knowing” that a task has been completed. Specifically, they argue that the common symptoms of OCD—washing, checking, fear of causing harm, etc.—are those that evolutionarily would have been related to the security of the organism and its fellows. This need for security leads to the evolution of a security-seeking system. Because there are no external stimuli that indicate the completion of a security-seeking task (for example, there could always a predator that the animal has missed), the completion of such tasks is indicated by an internally generated “feeling of knowing”. Obsessive-compulsives have a deficit in generating this subjective sensation, leading to the odd phenomena in which the obsessive-compulsive is perfectly aware, objectively, that, for example, their hands are perfectly clean, but they do not feel clean, leading to further washing.

The SEC/OCD Model

Huey et al’s (2008) model of OCD expands on Szechtman &Woody’s model and also on their own earlier work where they propose that complex behaviors with beginnings, middles, and ends are stored in the prefrontal cortex in the form of Structured Event Complexes, of SECs. For example, the knowledge of how to correctly eat dinner at a restaurant—finding a seat, ordering, eating, paying the bill, leaving—would be an SEC. SECs are usually implicitly recalled, and in this respect are similar to procedural memory. SECs are stored when a complex sequence of behavior leads to a reward, in order that such a sequence may be repeated. As evidence of these SECs, patients with damage to the prefrontal cortex have often reported difficulty with ordering and sequencing events and actions.

Just as the completion of an SEC can be rewarding, so too can the inability to complete an SEC can feel punishing. Furthermore, there are SECs that are themselves punishing but which bring about the removal of punishment: for example, few people feel good about doing their taxes, but most are relieved when their taxes are finally done.

In the SEC/OCD model, it is proposed that the initiation of an SEC is accompanied by a motivational signal, experienced as anxiety encouraging the animal to complete the SEC. In healthy subjects, the completion of the SEC is accompanied by a reward signal. According to the model, obsessive-compulsives have a deficiency in this latter process. Although the SEC is complete, the obsessive-compulsive does not have the sensation that it is done. This leads the anterior cingulate cortex to produce an error signal. The orbitofrontal cortex responds to this error as punishment, leading to a feeling of anxiety. This feeling is unconscious, leading the obsessive-compulsive to attempt to assign an explicit cause to it. This interpretation forms the basis of an obsession. The compulsion is caused by the fact that the completion of an SEC, for example hand washing, gives the obsessive-compulsives only partial relief, so that they feel they must repeat the SEC.

In regards to the basal ganglia, Huey et al suggest that just as it facilitates some motor actions while suppressing others, so too does it gate SECs. It is proposed that the basal ganglia sets thresholds for the activation of SECs, and when this threshold is lowered, for example by damage, it can lead to the overactivation of SECs, causing symptoms of OCD.

Conclusion

The cognitive neuroscience of OCD is still in its infancy. Much work is still to be done. However, Huey at al’s model provides a useful paradigm for further work. It shares and integrates elements from many of the previous models: along with expanding on Szechtman & Woody, it provides an explanation of why undue importance would be attached to fleeting thoughts as per the cognitive-behavioral model (the brain is looking for an explicit source of anxiety), and explains the possible psychological mechanisms of OCD that the standard model leaves out.

References

American Psychiatric Association (2000). Diagnostic and Statistical Manual of Mental Disorders: DSM-IV-TR, 4th ed Washington, DC: American Psychiatric Association Text Revision.

Fitzgerald, K., Welsh, R. C., Gehring, W. J., Abelson, J. L., Himle, J. A., Liberzon, I., & Taylor, S. F. (2005). Error-Related Hyperactivity of the Anterior Cingulate Cortex in Obsessive-Compulsive Disorder. Biological Psychiatry, 57(3), 287-294.

Huey, E. D., Zahn, R., Krueger, F., Moll, J., Kapogiannis, D., Wassermann, E. M., & Grafman, J. (2008). A psychological and neuroanatomical model of obsessive- compulsive disorder. The Journal of Neuropsychiatry and Clinical Neurosciences, 20(4), 390-408.

Maia, T. V., Cooney, R. E., & Peterson, B. S. (2008). The neural bases of obsessive- compulsive disorder in children and adults. Development and Psychopathology, 20(4), 1251-1283.

Markarian, Y., Larson, M. J., Aldea, M. A., Baldwin, S. A., Good, D., Berkeljon, A., & ... McKay, D. (2010). Multiple pathways to functional impairment in obsessive– compulsive disorder. Clinical Psychology Review, 30(1), 78-88.

McKay, D., Taylor, S., & Abramowitz, J. S. (2010). Obsessive-compulsive disorder. In D. McKay, J. S. Abramowitz, S. Taylor, D. McKay, J. S. Abramowitz, S. Taylor (Eds.) , Cognitive-behavioral therapy for refractory cases: Turning failure into success (pp. 89-109). Washington, DC US: American Psychological Association.

Szechtman, H., & Woody, E. (2004). Obsessive-Compulsive Disorder as a Disturbance of Security Motivation. Psychological Review, 111(1), 111-127.

Personal Pronouns

Hampshire College Psychology of Language Introduction Consider the following statement: “You asked me to go to the store to pick up some eggs for grandma. I picked them up for her.” For a normal adult speaker of English, this sentence is completely comprehensible; furthermore, it is a statement that would be easily and naturally produced. However, imagine that you are an alien with no understanding of English. Your English-speaking companion makes this statement, helpfully pointing at you when she says “you”, herself when she says “me” and “I”, and grandma when she says “her”. After a few conversations like this, you think you have gotten the hang of English. Walking up to your companion (who is sick at home) after giving grandma a ride, you proudly state: “You drove grandma to the store. Her picked up some eggs for her. Oh! Are I sick? You hope me get better!” From a theoretical standpoint, pronouns should be hard, and it is remarkable children can use them properly. When using pronouns, one must decide what 1. person & gender to use (are you talking about yourself [1st Person]: “I/me/my/mine”; to someone else [2nd Person]: “you/your/yours”; or about someone else entirely [3rd Person]: “he/him/his/she/her/hers/it/its”? In regards to 3rd Person, is the referent a person [“he/she”] or an object [“it’], and is it male or female?) and what 2. case to use (what function does the pronoun have in the sentence? Is the sentence about something the referent does [Nominative, Subjective]: “I/you/he/she/it”; something that is being done to the referent [Objective]: “me/you/her/him/it”; describing something as the property of the referent [Adjectival Genitive] or naming it as such [Nominal Genitive]: “my/your/his/her/its” or “mine/your/his/hers/its”; or something the referent is doing to itself [Reflexive]: “myself/yourself/himself/herself/itself”) and whether you are talking about one person or thing or more than one person or thing. You must also realize that although you can freely interchange 3P pronouns and names, it is not acceptable to refer to yourself or the person you are talking to by name (Chiat, 1986). The issues that will be focused on in this paper are those related to shifting reference, pronoun reversal, and the use of names or pronouns amongst typically developing children and children with autism. Shifting reference Most words name things: more importantly, they always name the same thing. A table is a table, Mr. Jones is Mr. Jones, the teacher is the teacher, regardless of whether you are talking, your friend is talking, you are reading a book, etc. One thing might have multiple names, or one name might signify multiple things, but the meaning of the name does not change depending on who is speaking (Clark 1978; Fay and Schuler, 1980; Ricard et al., 1999). Children learning a language must comprehend, through some means, that the person the words “you”, “I”, or “me” refer to changes depending on who is speaking to whom (Bates, 1990; Chiat, 1986; Clark, 1978; Ricard, Girouard, and Gouin-Decarie, 1999). How do children understand these rules? This question has intrigued psycholinguists for some time in regards to the light in might show on the connections between language, the conceptions of self and other, and theory of mind. Charney (1980) noted three ways in which children might understand pronouns: speech-role referring, person referring, and person-in-speech-role-referring. In a role-referring understanding, the child correctly understands the pronouns to refer to different members of the discourse depending on who is speaking. This understanding requires that the child have some sort of non-egocentrism, allowing it to take the point of view of others. In a person-referring understanding, the child understands the pronouns as a sort of name (see below). In a person-in-speech-role understanding, the child learns the pronouns most relevant to itself. The child understands pronouns in relation to the child’s own speech roles, i.e., it understands that “I” refers to it when it is speaking, but may not understand that “I” refers to others when they are speaking. This last theory is the one Charney supports. Pronoun use by typically developing children A natural assumption would be that children, on hearing themselves referred to as “you” and their parents referring to themselves as “I”, would assume that these terms are a type of name (Clark, 1976): our alien in the introduction made precisely this type of error. The child would assume that it is “you” and either its parent or adults in general are “I”. This phenomenon has been referred to as “pronoun reversal” (although “nonreversal” might be a more accurate term [Fay and Schuler, 1980; Fay, 1982], as the error in fact stems from the child not reversing pronouns to accommodate speaker roles). Interestingly, pronoun errors of this type are rare; even more interestingly, despite their rarity they are still found amongst typically developing children, often enough to be well documented in the literature (Clark 1978; Cruttenden, 1977; Chiat, 1986). According to Bates “it is quite common at age twenty to twenty-four months for a child to say ‘carry you/hold you/help you’ to mean ‘carry me/hold me/help me’” (1990). Cooley (1908) noted in a diary study that his third daughter would use “she” and “I” to refer to herself from the age of 1;11-2;3, such as in the statement “I carry you”, expressing the desire to be carried. Inconsistent reversals were also noted, such as “I want to take a walk with me”. Chiat (1981) performed a case study in 3 sessions with the subject, Matthew. The sessions took place at ages 2;4.16, 2;4.24, and 2;5.11, and Matthew’s comprehension and production were tested, the latter naturalistically in the 2nd session and with some attempts to elicit pronouns in the third. In the second session, Matthew’s use of 1P pronouns was usually correct, but he almost never used the correct pronoun for the addressee, as in the examples “I cry”=you’ll cry. This was particularly true in possessive contexts, such as “That my umbrella”=that’s your umbrella. 2P pronouns were used to refer to himself, as in “You’ll cry”=I’ll cry. Also, pronouns were occasionally inconsistent, with both the correct and incorrect forms used in a single utterance, similarly to Cooley’s observations. In the 3rd session, reversals of pronouns in regards to the addressee were still present, but had become rare, with Matthew often correcting himself. Despite these errors in production, Matthew’s performance on tests of comprehension was perfect. In a cross-sectional and longitudinal study by Loveland (1984) a correlation was found between mastery of different spatial points of view and pronoun errors, with some reversal errors observed amongst those children who did not understand different points of view. These errors often happened in contexts where the child was asked a question and repeated the pronoun used, e.g. “What do I have?” “I have cup”. Errors in comprehension were noted. Jordan (1989), in a comparison of autistic, typical, and mentally handicapped children, noted errors made by a few of the typical children in comprehension and production, with two typical children misunderstanding “you” as referring to the speaker and 3 children making errors in the production of “you”, one of them also making an error in the production of “me”. Oshima-Takane’s (1992) case study followed a pronoun reversing child, David, from age 1;11-2;10. The data they collected were his performance on comprehension tasks, 45-minute to 2 hour samples of his speech, and information from interviews with his mother and babysitter. At age 1;11 David’s mother had noticed that he was making consistent pronominal errors. At that time, he would use 1P pronouns to refer to the addressee 94% of the time and 2P pronouns to refer to himself 100% of the time. By the age of 2;10 his errors had almost completely disappeared. However, the development of the correct use of 1P and 2P pronouns was significantly different: while the error rate for 1P pronouns declined regularly between the 2;4-2;10, the error rate for 2P pronouns remained pretty much constant until 2;8, dropping dramatically between 2;8 and 2;10. In regards to comprehension, up until 2;4 he understood “you” as referring to himself even when he wasn’t the one being addressed. Oshima-Takane attributed David’s errors to a lack of experience with people using pronouns when talking to each other and not to him, making it difficult for him to generalize. Fraiberg and Adelson (1977) noted that blind children, capable in all other respects, often reversed pronouns well into their 5th year, which she attributed to the difficulties of forming a concept of self without the visual modality. And, in perhaps the most striking example of pronoun reversal, a deaf child was noted to make reversal errors in pointing, even interpreting all “you” signs as referring to herself (Bates 1990)! However, as stated before, pronoun errors are exceedingly rare amongst typically developing children (Huxley, 1970; Charney, 1980). Much more commonly, children will use names instead of pronouns. This might reflect a confusion about pronouns that causes the child to avoid them altogether, as evidenced by the fact that children who use names master pronouns more quickly when they begin to use them (Bates, 1990)—suggesting these children were using the time to work out what pronouns actually mean. It might also be caused by the fact that the nominal style is what the child often hears, as parents will often use names in order to effectively get the child’s attention (Chiat, 1986; Bates, 1990). Interestingly, there seems to be a distinction in the child’s use of names vs. pronouns when they use both, where the name refers to the physical body and the 1P pronoun to the self as an actor (Cooley, 1908). Autism and personal pronouns Whereas pronoun reversal is rare amongst typically developing children, amongst autistic children it is common enough that it is often considered pathognomic of the disorder (Jordan, 1989; Hobson, 1990). As Kanner wrote (qtd. in Lee et. Al., 1994): Personal pronouns are repeated just as heard, with no change to suit the altered situation. The child, once told by his mother “Now I will give you your milk,” expresses the desire for milk in exactly the same words. Consequently, he comes to speak of himself always as “you,” and of the person addressed as “I”. What Kanner described here is the phenomenon of echolalia, where the autistic child associates statements with the situation as they, the child, perceive it, and not with the parent’s mental state or intentions (Charney, 1981; Hobson, 1990). It is also possible that the child’s errors may be traced to their difficulties in gestural behavior and joint attention (Fay and Schuler, 1980). Autistic difficulties with pronouns are well documented in the literature (Fay and Schuler, 1980). Jordan (1989) found that while errors were rare amongst typical and mentally handicapped children, 9 out of the 11 autistic children made the maximum number of possible errors in the experiment in the production of both 1P and 2P pronouns. 3 of these children made pronoun reversals. The autistic children were also much more likely to use a name instead of “you”, while their results for names vs. pronouns in referring to themselves were more scattered. One child used her name 3 times and the experimenter’s names 7 times for “you”, with the numbers being reversed for “me”, indicating confusion about identity. Lee et al. (1994) found, in preparation for their study, that teachers reported several cases of pronoun reversal amongst autistic students, such as the student who told a teacher on return from sick leave “I’m better now”. Lee et al. (1994), in comparing autistic children with other mentally disabled children, found a tendency amongst autistic children to use proper names instead of the pronouns “I”, “me”, and “you”, that was not found amongst the other children. There was also a tendency to use the pronoun “I” instead of “me”. There were however no significant cases of pronoun reversal, although two autistic subjects did respond to the question “who can see X?” with the response “I can’t” as opposed to “you can”. Strangely, though, one of the subjects who had performed capably throughout the experiment said, on leaving, “Thank you for seeing you, Tony”. Lee et al. interpreted these results to a lack of a sense of “me-ness” or “you-ness”: the autistic subjects, according to their interpretation, lacked the sense of self (and other) as actor that Cooley (1908) had described. This also could explain why those autistic subjects who performed well could still experience occasional lapses, and their use of names for pictures of themselves and others. Proposal for future studies The fact that pronominal errors are rare amongst typically developing children means that systematic, large-scale experiments have rarely been done. Most information on personal pronoun difficulties has come, instead, from detailed case studies. Strangely, though, I did not encounter such case studies in regards to autistic children. I propose that such a study be performed, testing both production and comprehension. Diary studies such as Cooley’s (1908) would also be insightful. This would allow for a comparison between the pronoun use of otherwise typically developing children with pronominal errors and autistic children with pronominal errors. As the cognitive reasons for the errors made by autistic children are fairly easily understood but the cognitive reasons that some children should reverse pronouns when they have the same capabilities as their peers are not, such a comparison could shed light on the latter. For example, it could distinguish whether the reasons for pronoun errors amongst typically developing children are primarily cognitive or based on abnormal experience of pronoun use (as Oshima-Takane [1992]) suggests. It would also give a more in depth understanding of autistic pronouns. References Bates, E. (1990). Language about me and you: pronominal reference and the emerging concept of self. In, D. Cicchetti and M. Beeghly (Eds.), The Self in transition: infancy to childhood (165-182). Chicago: The University of Chicago Press. Charney, R. (1980). Speech roles and the development of personal pronouns. Journal of Child Language, 7, 509-528. Charney, R. (1981). Pronoun errors in autistic children-support for a social explanation. British Joumal of Disorders of Communication, 15(1), 39-43. Chiat, S. (1981). If I were you and you were me-the analysis of pronouns in a pronoun- reversing child. Journal of Child Language, 9, 359-379. Chiat, S. (1986). Personal pronouns. In, P. Fletcher and M. Garman (Eds.), Language acquisition: studies in first language acquisition, 2nd Ed. (339-355). New York: Cambridge University Press. Clark, E. (1978). From gesture to word: on the natural history of deixis in language acquisition. In, J. Bruner and A. Garton (Eds.), Human growth & development: Wolfson College Lectures, 1976 (85-120). Oxford: Oxford University Press. Cooley, C. H. (1908). A study of the early use of self-words by a child. The Psychological Review, 15(6), 339-57. Cruttenden, A. (1977). The acquisition of personal pronouns and language 'simplification'. Language and Speech, 20(3), 191-197. Fay, W.H., & Schuler, A. L. (1980). Emerging language in autistic children. Baltimore: University Park Press. Fraiberg, S. & Adelson, E. (1977). Self-representation in language and play. In, S. Fraiberg, Insights from the blind (248-270). New York: Basic Books, Inc. Hobson, R. P. (1990). On the origins of self and the case of autism. Development and Psychopathology, 2, 163-181. Huxley, R. (1970). The development of the correct use of subject personal pronouns in two children. In, G. B. Flores d'Arcais & W. J. M. Levelt (Eds.), Advances in psycholinguistics. New York: American Elsevier Publishing Company, Inc. Jordan, R. R. (1989). An experimental comparison of the understanding and use of speaker-addressee personal pronouns in autistic children. British Journal of Disorders of Communication, 24, 169-179. Lee, A., Hobson, R., & Chiat, S. (1994). I, you, me, and autism: An experimental study. Journal of Autism and Developmental Disorders, 24(2), 155-176. Loveland, K. A. (1984). Learning about points of view- spatial perspective and the acquisition of 'I/you'. Journal of Child Language, 11, 535-556. Oshima-Takane, Y. (1992). Analysis of pronominal errors-a case study. Journal of Child Language, 19, 11-131. Ricard, M., Girouard, C. P., & Gouin-Decarie, T. (1999). Personal pronouns and perspective taking in toddlers. Journal of Child Language, 26, 681-697.

Utilitarianism

It is my belief that human beings do things for one of two reasons: pleasure or impulse/habit. Let me specify: by "pleasure" I mean only what they BELIEVE will cause them more pleasure than pain (however human beings are often quite horrid at making such judgements), and it is also the case that even though they may rationally believe that something will more pain than pleasure in the long term--such as drug use--nevertheless for psychological reasons the short-term net pleasure outweighs the long-term net pain. Indeed, all such pleasure/pain decisions are ultimately made in regards to how they make us feel right now, in the immediate future.
(And though it's irrelevant to this argument, by "impulse/habit" I mean those actions that come from no decision, such as reflex actions.)
Many would argue at this point that many times people resist doing what they believe will cause them the most pleasure because it is "wrong". But it seems to me that in cases like this the decision is made on the basis of net pleasure: when we avoid doing something we really want to do because it's "wrong", we are responding to something within us that we believe would cause us to experience pain in response to the "wrongness", and we find that this pain outweighs any potential pleasure. The inverse is true when we do something we would rather not because it's "right": we decide that the pain that would result from NOT doing what's right is greater than the pleasure. (By the way, "right" depends on one's value system, so for instant rationalists behave rationally because to not do so would violate their value system, causing pain.)
Some people get very upset at this point and say "does that mean that the only reason we are altruistic is because it makes us feel better?" to which I say: yes. However, there's an assumption here which I do not understand: the idea that there's something wrong with us performing altruistic actions because they make us feel good. What's in the least bit wrong with the fact that doing good things for other people makes us ourselves feel good? It seems to me that this is a great confirmation of the goodness of human nature!
(By the way, in regards to self-destructive behavior, once again my contention is that the pain is outweighed by the psycholgocial pleasure, or is outweighed by the pain that would be caused by not giving in to compulsion.)
That is my explanation of individual motivation. Now onto it's implications for ethics, which is utilitarianism. "What is good is what will ultimately cause the greatest amount of net pleasure for the greatest number of entities." (I use "entities" so that this definition can include pleasure beyond hat of human beings.) I am humbly following John Stuart Mill here, but adding a lot of my own touches.
First let me defend my assertion that pleasure=good. My observation is that this is, in fact, what human beings already believe, although perhaps not consciously. Consider: can you think of a single thing that is considered "good" that is not expected to cause pleasure? If we give medicine to people it's because we expect that it will cause them long-term pleasure (and this belief causes us pleasure). If we save someone's life it's because we believe that living is somehow more pleasurable than dying (and once again, when with this belief in mind we save someone's life, it makes us feel good). If someone is a selfish psychopath and considers killing people "good" it is only because, being incapable of taking others' pain into account, they derive pleasure from it. If people believe abortions are OK it is because they believe the potential pain of the mother is more important to avoid than the potential pain of the fetus (which may not even exist); if they are against abortion it's because they believe the opposite (this is a massive oversimplification of the issue, by the way). If someone tries to get people to turn to Christ it is because they believe that this will cause those people more long term pleasure when they are saved.
(Religion, in fact, depends on a certain hedonism, since all religions I know of offer some sort of ultimate reward and/or punishment to support their claims that you should do this and not that. Even religious people who are not concerned with this ultimate reward still behave in the way proscribed by their faith because to do otherwise would cause net pain.)
"The greatest pleasure for the greatest number of entities." The "greatest number of entities" part is a bit harder to justify, except that I once again believe it is a natural belief of humanity, and also I believe it is a logical consequence of hedonism if one recognizes the fuzziness of "self" (to be discussed in some future post).
Finally, I am not sure I believe Utilitarianism to be the ultimate form of morality, but I do believe it is an important part. I also think that it is of ultimate importance to qualify utilitarianism with a fundamental respect of individual rights, since otherwise it is very easy for forms of society such as dictatorships, fascist, communist, etc., to be justified. Of primary concern is the right to freedom of thought and speech, for reasons enumerated in my "Old FaceBook Note: My thoughts on the UU principles (for my fellow UUs)- Part 2", and also for more epistomolgical reasons which I will discuss later.