Depression Is Not Just a "Bad Mood": What Happens in the Brain and How to Treat It

If someone has a broken leg, nobody says "just walk." If someone's heart is hurting, nobody says "just stop being afraid." Yet with depression, "just pull yourself together" is treated as obvious common sense. But depression is not a mood. It is a state of the brain.

Neurobiology: What Is Really Happening

MRI studies have documented structural changes in the brain during chronic depression. Sheline et al. (PNAS, 1996) demonstrated that women with recurrent depression showed a 9–13% reduction in hippocampal volume compared to a control group. The hippocampus is responsible for memory, learning, and mood regulation.

At the neurochemical level, at least three systems are involved:

• Serotonin — regulates mood, sleep, and appetite. In depression, serotonergic transmission is reduced.
• Dopamine — responsible for motivation and the experience of pleasure. Depression "switches off" the ability to enjoy things that were once pleasurable (anhedonia).
• Noradrenaline — concentration, energy, stress response. Its dysregulation explains fatigue and the "brain fog" that many sufferers describe.

"Depression is not a lack of willpower. It is a condition in which neurochemical changes physically impair the expression of any willpower" — Malhi & Mann, The Lancet, 2018

Signs Worth Knowing

According to DSM-5 criteria, a diagnosis of a major depressive episode requires at least 5 of 9 symptoms present for 2 or more weeks:

1. Depressed mood for most of the day
2. Markedly diminished interest or pleasure in all or almost all activities
3. Significant weight change or change in appetite
4. Sleep disturbance (insomnia or hypersomnia)
5. Psychomotor agitation or retardation
6. Fatigue and loss of energy
7. Feelings of worthlessness or excessive guilt
8. Difficulty concentrating or making decisions
9. Recurrent thoughts of death or suicide

Important: this list is not for self-diagnosis. It is a reference for understanding when to seek professional help.

What Works: The Evidence Base

A meta-analysis by Cuijpers et al. (World Psychiatry, 2019), encompassing 522 studies (over 116,000 participants), compared the effectiveness of various approaches:

• CBT (cognitive-behavioural therapy) — effect size 0.71, among the most effective approaches
• Behavioural activation — effect size 0.74 (a simple yet powerful activity-scheduling technique)
• Antidepressants (SSRIs) — effect size 0.30, lower than psychotherapy
• Combined therapy and medication — best outcomes for moderate to severe depression

Why Early Help Matters

Every untreated depressive episode increases the risk of the next one — and makes it harder to overcome. Post (Journal of Psychiatric Research, 1992) described the "kindling" mechanism: the brain becomes progressively more vulnerable to depression after each episode. Early intervention literally protects the brain from further damage.

In Ukraine, since 2022, rates of depression and PTSD have risen significantly. A 2023 WHO study found that one in three Ukrainians experiences signs of an anxiety or depressive disorder. Seeking help from a psychologist is not a luxury, nor does it mean something is "wrong with your head." It is a normal act of self-care.

Sources:

• Sheline Y.I. et al. (1996). Hippocampal atrophy in recurrent major depression. PNAS, 93(9). doi:10.1073/pnas.93.9.3908
• Malhi G.S., Mann J.J. (2018). Depression. The Lancet, 392(10161). doi:10.1016/S0140-6736(18)31948-2
• Cuijpers P. et al. (2019). Comparing psychotherapies for adult depression. World Psychiatry, 18(1). doi:10.1002/wps.20600