Mood-Congruent and State-Dependent Memory

Snap Shot

• The question: Does a person’s mood or physiological state, at the time of an event or at the time of recall, affect what the person remembers, and does that matter for how witness accounts are taken and evaluated?
• What the research shows: Mood-congruent memory, the tendency to recall material whose emotional tone matches one’s current mood, is reliable across many studies and is also found in depression. Mood- and drug-state-dependent memory, better recall when the state at retrieval matches the state at learning, has been found mainly in free recall and under specific conditions.
• What it does not show: State-dependent effects are modest, have produced inconsistent results across studies, and are weak or absent in recognition and cued recall. The research does not show that reinstating a mood or an intoxicated state will recover accurate memories, or that a witness’s mood made a particular account inaccurate.
• The law: Testimony on mood and memory is assessed under Rule 702 and, in courts-martial, Houser; in Arizona, Chapple and Nordstrom allow general memory testimony in the court’s discretion, and Lindsey bars opinions on a particular witness’s credibility.
• Issues for each side: Prosecutors can explain that mood-congruent recall describes which memories come to mind, not that those memories are false, and that open-ended interviewing aids accurate recall; defense counsel can examine whether mood at interview, depression, or intoxication at encoding shaped an account, and each side should keep these modest group effects in proportion.

A person’s internal state is part of the context in which a memory is formed. Mood, arousal, alertness, and the effects of alcohol or other drugs are encoded along with the event and can affect later recall. Three related ideas describe this. State-dependent memory refers to better retrieval when a physiological condition present during learning, such as intoxication, is present again at testing. Mood-dependent memory is the emotional counterpart: remembering may be easier when a person is in the same mood at testing as during learning. Mood-congruent memory is different. It is the tendency to learn or recall more readily material whose emotional tone matches one’s current mood, so that a sad person more easily recalls sad events, whenever and in whatever mood those events were experienced.

These effects reach court because witnesses are often interviewed while distressed, complainants and accused persons may have been drinking or using drugs at the time of the events, and some witnesses have depression or other mood disorders. The parties may argue that a witness’s mood colored an account, that an intoxicated witness can remember more when intoxicated again, or that an interview technique recovered more detail by reinstating the witness’s state of mind. The research supports some of these claims in limited form and does not support others.

This paper summarizes the early findings, their uneven record across later studies, state dependency with alcohol and other drugs, memory biases in depression, how interview methods use the underlying principle, and the limits of the evidence. External settings as retrieval cues are covered in the Context Effects paper, and alcohol’s broader effects on memory are covered in Alcohol and Memory and Intoxication and Memory.

Early Findings and the Underlying Principle

In an influential series of studies, Bower (1981) induced happy or sad moods in participants and reported both mood-dependent recall, with better recall of material when the mood at test matched the mood at learning, and mood-congruent learning and recall, with better memory for material matching the participant’s mood. Bower proposed that moods act as nodes in an associative memory network, so that an active mood spreads activation to memories linked with it. The proposal tied these findings to the broader principle of encoding specificity, under which a retrieval cue helps to the extent that it overlaps with what was encoded (see Context Effects). A mood present at encoding can become one of those cues.

The two phenomena have fared differently since then. Mood-congruent memory has been found repeatedly. Mood-dependent memory has proved much harder to obtain; a later review noted that it had been shown only sometimes, that the conditions producing it were not well understood, and that it remained controversial (Eich, 1995). A meta-analysis of mood-state-dependent memory studies found evidence of the effect overall, with considerable variation across studies and procedures (Ucros, 1989), although later reviews, including the one noted above, found it inconsistent.

Mood-State-Dependent Memory: Elusive but Not Absent

Research by Eich and colleagues identified conditions under which mood-dependent memory does appear. Their account holds that the effect is more likely the more a person must rely on internal resources, rather than external aids, both to generate the events and to generate the cues for retrieving them. In three experiments testing that principle, participants in an induced pleasant or unpleasant mood generated personal memories in response to neutral words and, two or three days later, freely recalled those memories in the same or the other mood; recall was more likely when the moods matched (Eich et al., 1994). A later study found that simulated moods, in which participants only acted happy or sad, did not produce mood-dependent effects, suggesting that genuine, strong moods are required (Eich & Macaulay, 2000).

The practical implication is narrow. Mood-dependent effects are most likely in free recall of self-generated material under strong, genuine moods, and least likely when a person is asked specific questions, shown items to recognize, or given other strong cues. That describes the reverse of most forensic questioning, in which witnesses are asked about particular details and shown photographs or lineups.

Mood-Congruent Memory

Mood-congruent memory is better established. A meta-analytic review found reliable mood-congruent recall of emotionally toned material in both clinically depressed people and people in whom a mood had been induced, with nondepressed people tending to recall relatively more positive material (Matt et al., 1992). A more recent systematic review of studies that induced moods in healthy participants found that mood-congruent memory appears in several forms: better memory for previously encoded material that matches the mood, preferential recall of personal events that match the mood, and sometimes false memories for mood-congruent items that were never presented (Faul & LaBar, 2023). The same review described conditions in which people instead recall mood-incongruent material, as when they try to repair a negative mood.

For witnesses, mood-congruent memory bears on which memories come to mind and how they are framed, not on whether a particular remembered event occurred. A distressed witness may more readily recall distressing aspects of an event, and a witness interviewed in a calmer state may report a somewhat different emphasis. The finding that mood can also increase false recognition of mood-congruent items comes from laboratory studies of word lists and similar materials (Faul & LaBar, 2023), and it does not show that emotional witnesses generally report events that did not happen.

Depression and Memory Biases

Memory biases are a well-documented feature of depression. A meta-analysis of 153 studies found a small overall explicit memory bias in depression (Hedges’ g = 0.24) that varied with the emotional tone of the material and the memory task; among people whose depression had remitted, the bias was not significant under ordinary conditions but appeared after a mood or stress induction, and the authors concluded that the bias may persist beyond a depressive episode (Everaert et al., 2022). A meta-analysis of 20 studies of implicit memory found that depressed groups showed preferential implicit memory for negative information and nondepressed groups for positive information, with self-relevance an important moderator (Gaddy & Ingram, 2014). People with depression and other emotional disorders also tend to recall personal memories in an overgeneral way, summarizing categories of events (“I always argued with him”) rather than retrieving a single specific occasion, a pattern linked to rumination, avoidance of distressing material, and reduced executive control (Williams et al., 2007).

These findings have forensic relevance in both directions. Overgeneral recall can make it harder for a witness with depression to supply the date, sequence, or specific details of one occasion; the research does not allow an expert to say whether any particular difficulty reflects depression, ordinary forgetting, or something else; and a negative memory bias can shape the emphasis of an account. Neither finding shows that a person with depression is an unreliable witness, and the research concerns group tendencies in recall, not the accuracy of what a particular person reports. Questions about a particular witness’s mental health and capacity raise individualized issues beyond the scope of this paper.

Alcohol, Drugs, and State-Dependent Retrieval

The drug version of state dependency has a longer history. In an early study, male volunteers learned material while sober or after drinking and were tested the next day sober or intoxicated. On recall tasks, performance was better when participants were intoxicated at both sessions than when they were intoxicated only at learning, but on a recognition task changing state had no significant effect (Goodwin et al., 1969). A review of the drug literature concluded that state-dependent effects appear mainly when retrieval must be generated from internal cues, as in free recall, and largely disappear when effective external cues are provided, as in cued recall and recognition (Eich, 1980).

These effects must be kept separate from the larger effect of alcohol and many drugs, which is to disrupt encoding at the outset. Material that was poorly encoded because of intoxication is not recovered by becoming intoxicated again, and state dependency is not a basis for re-intoxicating a witness. Recent work also cautions against simple assumptions in the other direction. In a 2026 quasi-experimental study of 131 adults who watched a mock crime video, regular cannabis users intoxicated at both viewing and interview, users intoxicated only at interview, sober users, and sober non-users did not differ statistically in recall or identification performance when interviewed with the Sketch Cognitive Interview; stronger subjective intoxication was associated with poorer memory performance, and participants intoxicated at both sessions showed inflated confidence in their errors on target-absent lineups (Kloft-Heller et al., 2026). Intoxication at encoding, its effects on recall and identification, and alcohol-related blackouts are addressed in Alcohol and Memory and Intoxication and Memory.

Interviewing and Reinstating the Witness’s State of Mind

The principle that internal and external context can serve as retrieval cues is applied in the Cognitive Interview, which asks a witness to mentally recreate the setting of the event, including the witness’s own thoughts and feelings at the time, before giving a free narrative (Fisher & Geiselman, 1992; Fisher & Schreiber, 2007). Mental reinstatement is one component alongside rapport building, transferring control to the witness, encouraging a complete report, and open-ended questioning. A meta-analysis found that the Cognitive Interview reliably increased correct information with a smaller increase in incorrect details (Memon et al., 2010), and Lane and Houston (2021, pp. 130–131) summarize that research as showing more correct information without a loss of accuracy. The Cognitive Interview has had little effect on identification accuracy (Fisher & Schreiber, 2007).

Asking a witness to recall feelings at the time is not the same as inducing a mood, and the evidence for the Cognitive Interview concerns the full procedure rather than mood reinstatement specifically. The mood-dependent memory research does not show that deliberately making a witness distressed, or recreating an intoxicated state, will improve accurate recall. The practical lessons are more modest: interview conditions that let the witness generate a free narrative with open prompts suit the conditions under which state effects appear, and a witness’s mood at interview is worth noting because it may affect which aspects of an event the witness emphasizes.

Limits of the Evidence

Most of this research uses university students, induced moods of short duration, and word lists or brief personal memories, tested over minutes to days. Real-world moods surrounding crimes are stronger and more complex, and real delays are longer; the research does not settle how state effects operate under those conditions. Findings on mood-dependent memory have been inconsistent across studies and procedures (Eich, 1995; Ucros, 1989), and state-dependent effects of drugs appear mainly in free recall and fade with strong cues (Eich, 1980). The alcohol state-dependency literature rests largely on older laboratory studies with small samples, beginning with Goodwin et al. (1969), and should be described as dated. Depression findings concern group differences in which memories are retrieved and how specifically, not the accuracy of particular reports. No method allows an expert to determine whether a particular witness’s mood or state at encoding or at interview altered a particular detail.

Questions to Ask About This Research

When Goodwin et al. (1969) is offered for the idea that a person who had been drinking during an event would recall more after drinking again, counsel should ask whether the conclusion follows and whether it has held up: the effect appeared in recall but not recognition, later reviews found such effects mainly when retrieval cues are weak (Eich, 1980), and the larger effect of intoxication is impaired encoding. When mood-congruent memory is invoked to claim that an upset witness emphasized the negative, counsel should ask how large the effect is and whether it applies to this person, since meta-analyses describe average differences in which material is recalled, not errors in a given account (Matt et al., 1992; Faul & LaBar, 2023). When Bower (1981) is cited for mood-dependent recall, counsel should ask how much evidence supports the claim today, given the inconsistent findings and continuing controversy Eich (1995) reviewed. When depression is said to undermine a witness’s memory, counsel should ask what exactly was measured, because overgeneral recall concerns specificity, not whether events occurred (Williams et al., 2007). These questions are explained in “Reading Research Claims: A Guide for Attorneys” on this site.

Mood-Congruent and State-Dependent Memory and the Law

Federal and Military Standards

Expert testimony about mood, state, and memory is governed by Federal Rule of Evidence 702, as amended December 1, 2023, under which the proponent must show the court that it is more likely than not that the rule’s requirements are met, including that the opinion reflects a reliable application of reliable methods to the case. Daubert v. Merrell Dow Pharmaceuticals, Inc. (1993) made the trial judge a gatekeeper, and Kumho Tire Co. v. Carmichael (1999) extended that gatekeeping obligation to all expert testimony, including testimony based on technical or other specialized knowledge. In courts-martial, Military Rule of Evidence 702 tracks the federal rule, and the 2023 federal amendment took effect in the military rule in 2025 through Military Rule of Evidence 1102 (Joint Service Committee on Military Justice, 2025); practitioners should confirm current text. Military judges apply the six factors of United States v. Houser (1993). The uneven replication record of mood- and state-dependent memory bears on whether testimony relying on those effects rests on sufficient facts and reliable principles and whether it fits the facts of the case.

Arizona

Arizona Rule of Evidence 702 adopted the federal formulation and the Daubert standard effective January 1, 2012, and was amended effective January 1, 2024, to conform to the 2023 federal amendment (Ariz. Sup. Ct. Order R-23-0004). State v. Chapple (1983) is Arizona’s leading case on expert testimony about the reliability of memory and eyewitness accounts: excluding a qualified expert was an abuse of discretion on its facts, while admission generally remains within the trial court’s discretion, and State v. Nordstrom (2001) approved limiting such an expert to general factors without opinions on the accuracy of a particular witness. Experts may not opine on whether a particular witness is truthful or quantify how often witnesses of a given type are truthful (State v. Lindsey, 1986, 149 Ariz. at 475–76).

Special Issues in Legal Practice

The principles described above apply with equal force to every party in a legal proceeding. The science operates the same way regardless of who is asking the questions, and the research summarized here does not by itself favor either side. What differs between the parties is not the science but the vantage point — the particular places where these issues tend to surface, and the particular errors each party is best positioned to guard against. The two summaries below identify those recurring issues. They are offered for orientation, not as litigation strategy; in every case the controlling question is what the evidence in that case will, and will not, support, and the expert’s role is to inform the trier of fact rather than to advocate for either side.

Special Issues for Prosecutors

The research supports several propositions prosecutors can legitimately present. Mood-congruent memory concerns which memories come to mind and what a witness emphasizes, not whether remembered events occurred, so a distressed witness’s focus on distressing details can occur with ordinary memory processes and does not by itself show whether the account is accurate. Overgeneral recall in witnesses with depression can make it hard to isolate one occasion, and difficulty supplying dates or sequences does not by itself show fabrication, nor does it show accuracy; the research cannot say whether a particular error or gap reflects ordinary memory, depression, or something else. Open-ended interviewing consistent with the Cognitive Interview, including mental reinstatement of the setting, reliably yields more correct information with a smaller increase in errors (Fisher & Geiselman, 1992; Memon et al., 2010), and in one recent study cannabis-using mock witnesses interviewed this way did not differ as groups from sober witnesses in recall accuracy or completeness (Kloft-Heller et al., 2026). Investigators can strengthen the record by noting a witness’s emotional state and any substance use at the time of the events and at each interview.

The research also counsels caution. Testimony that reinstating a witness’s mood or feelings recovered particular accurate details goes beyond the evidence, which concerns the full interview procedure and does not isolate mood. Mood-congruent effects can include false recognition of congruent material in laboratory tasks, and a witness’s mood at interview may shape emphasis. Intoxication at encoding generally impairs memory, and state-dependency research offers little basis for treating details recalled by a previously intoxicated witness as recovered memories, and none for re-creating the state.

Special Issues for Defense

The research supports several propositions defense counsel can legitimately present. A witness’s mood at interview can influence which aspects of an event are recalled and how they are framed, and depression is associated with a small bias in memory for emotional material that may persist beyond an episode under some conditions. Intoxication at encoding generally impairs encoding at the levels tested, mainly reducing how much is recalled (in the 2026 cannabis study, intoxicated and sober groups did not differ in recall or identification), state-dependent retrieval appears mainly when cues are weak, and in one recent study participants intoxicated with cannabis when they viewed an event and when they were interviewed were more confident in their lineup errors (Kloft-Heller et al., 2026). Expert testimony explaining these principles, tied to evidence of the witness’s state at encoding and at each interview, can help the factfinder evaluate an account.

The research also counsels caution about the limits that apply to the defense. Mood- and state-dependent effects are modest, condition-specific, and inconsistent across studies, and they do not show that a witness’s account is inaccurate. Mood-congruent recall concerns emphasis and accessibility, not fabrication, and depression does not make a witness unreliable. The same principles apply to the accused, whose own mood, depression, or intoxication may affect what he or she recalls. An expert cannot tell the factfinder that a particular detail was produced or distorted by a witness’s mood or state.

This paper is for educational purposes only and is not legal advice. The author is a psychologist, not an attorney; summaries of law are general and must be verified against current authority or with a licensed attorney.

References

Bower, G. H. (1981). Mood and memory. American Psychologist, 36(2), 129–148. https://doi.org/10.1037/0003-066X.36.2.129

Eich, E. (1995). Searching for mood dependent memory. Psychological Science, 6(2), 67–75. https://doi.org/10.1111/j.1467-9280.1995.tb00309.x

Eich, E., & Macaulay, D. (2000). Are real moods required to reveal mood-congruent and mood-dependent memory? Psychological Science, 11(3), 244–248. https://doi.org/10.1111/1467-9280.00249

Eich, E., Macaulay, D., & Ryan, L. (1994). Mood dependent memory for events of the personal past. Journal of Experimental Psychology: General, 123(2), 201–215. https://doi.org/10.1037/0096-3445.123.2.201

Eich, J. E. (1980). The cue-dependent nature of state-dependent retrieval. Memory & Cognition, 8(2), 157–173. https://doi.org/10.3758/BF03213419

Everaert, J., Vrijsen, J. N., Martin-Willett, R., van de Kraats, L., & Joormann, J. (2022). A meta-analytic review of the relationship between explicit memory bias and depression: Depression features an explicit memory bias that persists beyond a depressive episode. Psychological Bulletin, 148(5–6), 435–463. https://doi.org/10.1037/bul0000367

Faul, L., & LaBar, K. S. (2023). Mood-congruent memory revisited. Psychological Review, 130(6), 1421–1456. https://doi.org/10.1037/rev0000394

Fisher, R. P., & Geiselman, R. E. (1992). Memory-enhancing techniques for investigative interviewing: The cognitive interview. Charles C Thomas.

Fisher, R. P., & Schreiber, N. (2007). Interview protocols to improve eyewitness memory. In M. P. Toglia, J. D. Read, D. F. Ross, & R. C. L. Lindsay (Eds.), The handbook of eyewitness psychology: Vol. 1. Memory for events (pp. 53–80). Lawrence Erlbaum Associates.

Gaddy, M. A., & Ingram, R. E. (2014). A meta-analytic review of mood-congruent implicit memory in depressed mood. Clinical Psychology Review, 34(5), 402–416. https://doi.org/10.1016/j.cpr.2014.06.001

Goodwin, D. W., Powell, B., Bremer, D., Hoine, H., & Stern, J. (1969). Alcohol and recall: State-dependent effects in man. Science, 163(3873), 1358–1360. https://doi.org/10.1126/science.163.3873.1358

Joint Service Committee on Military Justice. (2025). Amendments to the Military Rules of Evidence since 1984 (G. E. Maggs, Ed.; 2025 ed.). https://jsc.defense.gov/Portals/99/MRE%20Amendments%202025.pdf

Kloft-Heller, L., Junk, A., Dando, C. J., Sauerland, M., Otgaar, H., & Ramaekers, J. G. (2026). Cannabis intoxication does not impair eyewitness recall with the Sketch Cognitive Interview but increases confidence in lineup errors. Scientific Reports, 16, Article 10203. https://doi.org/10.1038/s41598-026-45069-0

Lane, S. M., & Houston, K. A. (2021). Understanding eyewitness memory: Theory and applications. New York University Press.

Matt, G. E., Vázquez, C., & Campbell, W. K. (1992). Mood-congruent recall of affectively toned stimuli: A meta-analytic review. Clinical Psychology Review, 12(2), 227–255. https://doi.org/10.1016/0272-7358(92)90116-P

Memon, A., Meissner, C. A., & Fraser, J. (2010). The cognitive interview: A meta-analytic review and study space analysis of the past 25 years. Psychology, Public Policy, and Law, 16(4), 340–372. https://doi.org/10.1037/a0020518

Ucros, C. G. (1989). Mood state-dependent memory: A meta-analysis. Cognition and Emotion, 3(2), 139–169. https://doi.org/10.1080/02699938908408077

Williams, J. M. G., Barnhofer, T., Crane, C., Hermans, D., Raes, F., Watkins, E., & Dalgleish, T. (2007). Autobiographical memory specificity and emotional disorder. Psychological Bulletin, 133(1), 122–148. https://doi.org/10.1037/0033-2909.133.1.122

Legal Authorities

Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993).

Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999).

State v. Chapple, 135 Ariz. 281, 660 P.2d 1208 (1983).

State v. Lindsey, 149 Ariz. 472, 720 P.2d 73 (1986).

State v. Nordstrom, 200 Ariz. 229, 25 P.3d 717 (2001).

United States v. Houser, 36 M.J. 392 (C.M.A. 1993).

Fed. R. Evid. 702.

Mil. R. Evid. 702.

Mil. R. Evid. 1102.

Ariz. R. Evid. 702.

Ariz. Sup. Ct. Order R-23-0004 (amending Ariz. R. Evid. 702, effective Jan. 1, 2024).

Related topic papers: Context Effects · Alcohol and Memory · Intoxication and Memory · Emotion, Stress, Trauma, and Memory · Improving Eyewitness Memory · Fading Affect Bias

Related topics from Arizona Forensic Services: Alcohol Blackouts: Alcohol Blackout / Amnesia