Why are we sad? Why do we commit suicide? Psychology 320

Moving on… to Sadness Thought questions for today What kinds of things make us sad? What is the difference between sadness, grief, and depression? Is there any evolutionary advantage to experiencing any of these? What do we do when we are sad? What do we feel (physiologically)?

Moving on… to Sadness Arguably the most negative, aversive emotion Also referred to as “distressed” Arises from failure or separation What is ”failure” (or separation) if not the result of an incorrect prediction? What are predictions if not “associations” that have been conditioned? The sensation is so intense, that we desperately seek “negative reinforcement” We often seek to restore things to “the way they were” before the sadness came on “I wish I could go back” Serves as heavily adaptive To restore an “environmental homeostasis” To ensure no failure To ensure social cohesion

Sadness in social context Most often, sadness is the result of failure in some social context Most often, in a social context, saddness is associated with “grief” Death Break up/divorce Argument Grief is not just social Grief is, essentially, the “sadness” associated with loss Grief is so predictable, that we have 5 stages (Kubler-Ross & Kessler, 2005) Denial Bargaining Anger Depression – often the longest stage Acceptance

Sadness We could talk about sadness in gradations Disappointed Sad Distraught Heartbroken Hopeless Grief-stricken As sadness continues, it gradually leads to more and more inactivity, lethargy, and eventually, withdrawal Withdrawal can occur in all aspects of life, though social is most evident

Sadness And “arousal”… Enhanced or increased neural activation Generally speaking, arousal is a good, positive thing Though can be negative, i.e. fear and anger Sadness is associated with reduced arousal – which kinda makes sense…

Sadness “Depression” = a neural depression of activity So, not surprising that: If sadness = reduced arousal And “Depression” is “depressed neural activity” That “Depression” = pervasive sadness Depression is often associated with “lack of motivation” And “motivation” or “being motivated” is most always associated with a drive to act, or in essence, arousal

Sadness – when there’s too much… Depression is often associated with: Lack of motivation (arousal) General cortical depression; systemic dysfunction; hightened HPA (and, perhaps – exhaustion) Feeling of despair (no goals will come to fruition; no expectations will be met) Learned helplessness – Seligman and Maier, 1967 Disruption of PFC and downstream targets (i.e. amygdala and dorsal raphe nucleus) Probably a misnomer Lack of desire The pursuit of something and/or feeling of want/wish Disruption of PFC and nucleus accumbens; amygdala Anhedonia The lack of desire and/or enjoyment of things pleasurable

Sadness and the Brain Sadness associated with a disruption in predictive power of associations PFC are especially lowly active

Sadness and the Brain Depression is associated with decreased cortical volume (thus grey matter) of the: PFC Cingulate Cortex Hippocampus Depression is associated with decreased connectivity (thus white matter) of: PFC-dependent, top-down inhibitory control of emotion Reward pathway (mesolimbic pathway) Depression is associated with: Increased activity in the amygdala Dysfunction of the “Dorsal Raphe Nuclei” A brainstem region that is responsible for making and projecting serotonin

The Brain and Suicide Recall again what we have going on in cases of depression (but also PTSD, Bipolar, and as we’ll see in a coming lecture, drug abuse and alcoholism): Decreased PFC control Increased Amygdala So what does that mean? Decreased logic and reason; Decreased ability to effectively predict causality; Decreased inhibition of amygdala More fear; More irrationality; More “Act now, Think later” Taken together – More Impulsivity

The Brain and Suicide So what is “impulsivity” So what do we know about suicide? 10th leading cause of death worldwide Approximately 43,000 deaths in US in 2014 Approximately 10-20 million attempts per year worldwide 3 of 4 deaths are male but 4 of 5 attempts are female In US, it is most often attempted by adolescents

The Brain and Suicide So what do we know about suicide? Most describe feeling “despair”, “hopeless”, “sad”, “depressed”, “alone”, etc. Approximately 2/3 of suicide victims are clinically depressed But how can we truly trust this statistic isn’t higher? Brains of suicide victims have decreased serotonin Brains of suicide victims have increased GABA Suicidality corresponds with structural abnormalities of PFC and PFC dysfunction including deficits in executive function Behavioral inhibition Spatial working memory Visuospatial conceptualization Visual attention Increased impulsivity Increased amygdala size (though equivocal – that is to say, the research is back and forth on this) Probably not causal but merely correlational

The Brain and Suicide Recall that more young people attempt suicide in US Increased stress on youth? Increased attention on suicide? Increased access to methods? Increased pressure from peers? Decreased PFC function!!!! Irrespective of sadness/depression/suicide risk – the PFC is not fully “online”, not fully developed until around age 25. Adolescents are behind the 8 ball already, let alone when their stress levels and/or depression start negatively influencing PFC activity. Males tend to be more impulsive than females Perhaps why males are “successful” more often – perhaps due to method

Well… this is depressing So what can we do to help this? Given what we know about depression, at-risk youth, and the brain… what kinds of things can we do to minimize the risk of suicide? In adolescents? In adults? Consider “learned helplessness hopefulness” Hypothetically – what could we do to manipulate the brain (at a reductionistic level) to overcome depression, sadness, and/or suicide?